Navigating the complexities of your 2012 Ram 2500 diesel engine can sometimes feel like deciphering a secret language, especially when the check engine light illuminates. The on-board diagnostics system, or OBD2, is designed to help you understand what’s happening under the hood. When that light comes on, your truck is trying to communicate through OBD2 codes. This guide provides a detailed breakdown of OBD2 trouble codes specific to the 2012 Ram 2500 diesel, helping you understand potential issues and take informed action.
Understanding OBD2 Codes for Your 2012 Ram 2500 Diesel
The OBD2 system is standardized across most vehicles, including your Ram 2500. It monitors various systems within your truck, from the engine and transmission to emissions control. When a problem is detected outside of normal parameters, the system generates a trouble code, which is stored in the truck’s computer and often triggers the check engine light.
These codes are five-character alphanumeric codes. The first character indicates the system affected (P for Powertrain, B for Body, C for Chassis, U for Network). The second character specifies the code type (0 for generic, 1 or 2 for manufacturer-specific). The third character denotes the subsystem (e.g., fuel and air metering, ignition system). The last two characters are specific fault codes.
While this list is extensive, remember that diagnosing OBD2 codes is the first step. Proper repair often requires further investigation and testing by a qualified mechanic.
Comprehensive List of 2012 Ram 2500 Diesel Obd2 Codes
Below is a detailed list of OBD2 codes that may appear in your 2012 Ram 2500 diesel. This list includes generic codes and manufacturer-specific codes relevant to Dodge Cummins diesel engines.
| Code | Description | Potential Causes | Possible Symptoms |
|---|---|---|---|
| P0008 | ENGINE POSITION SYSTEM PERFORMANCE BANK 1 | Timing chain or belt issues, camshaft or crankshaft sensor problems, mechanical engine damage. | Engine performance issues, rough running, misfires, difficulty starting. |
| P000F | FUEL SYSTEM OVER PRESSURE RELIEF VALVE ACTIVATED | Excessive fuel pressure, faulty fuel pressure regulator, fuel system malfunction. | Fuel leaks, engine performance problems, potential engine damage. |
| P0016 | CRANKSHAFT/CAMSHAFT TIMING MISALIGNMENT – BANK 1 SENSOR 1 | Misaligned timing chain or belt, faulty camshaft or crankshaft position sensor, mechanical timing issues. | Engine performance problems, rough idle, misfires, difficulty starting, decreased fuel economy. |
| P0030 | O2 SENSOR 1/1 HEATER CIRCUIT OPEN | Faulty O2 sensor, wiring issue, blown fuse in the heater circuit. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0031 | O2 SENSOR 1/1 HEATER CIRCUIT LOW | Short circuit in the O2 sensor heater circuit, wiring issue, faulty ECM. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0032 | O2 SENSOR 1/1 HEATER CIRCUIT HIGH | Open circuit in the O2 sensor heater circuit, wiring issue, faulty ECM. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0036 | O2 SENSOR 1/2 HEATER CIRCUIT OPEN | Faulty O2 sensor, wiring issue, blown fuse in the heater circuit. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0037 | O2 SENSOR 1/2 HEATER CIRCUIT LOW | Short circuit in the O2 sensor heater circuit, wiring issue, faulty ECM. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0038 | O2 SENSOR 1/2 HEATER CIRCUIT HIGH | Open circuit in the O2 sensor heater circuit, wiring issue, faulty ECM. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P003A | TURBOCHARGER BOOST CONTROL MODULE POSITION EXCEEDED LEARNING LIMIT | Turbocharger boost control module malfunction, actuator issues, mechanical binding in the turbocharger. | Reduced engine power, poor acceleration, check engine light. |
| P0046 | TURBOCHARGER BOOST CONTROL CIRCUIT PERFORMANCE | Faulty turbocharger boost control solenoid, wiring issues, vacuum leaks, PCM malfunction. | Reduced engine power, poor acceleration, check engine light. |
| P0049 | TURBOCHARGER TURBINE OVERSPEED | Turbocharger malfunction, boost control issues, excessive exhaust flow. | Whining or whistling noise from the turbocharger, reduced engine power, potential turbocharger damage. |
| P0053 | O2 SENSOR 1/1 HEATER RESISTANCE | Faulty O2 sensor with incorrect heater resistance. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0054 | O2 SENSOR 1/2 HEATER RESISTANCE | Faulty O2 sensor with incorrect heater resistance. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P006E | TURBOCHARGER BOOST CONTROL MODULE SUPPLY VOLTAGE CIRCUIT LOW | Low voltage supply to the boost control module, wiring issues, faulty module. | Reduced turbocharger performance, decreased engine power, check engine light. |
| P006F | TURBOCHARGER BOOST CONTROL SUPPLY VOLTAGE CIRCUIT HIGH | High voltage supply to the boost control module, wiring issues, faulty module. | Overboost condition, potential turbocharger damage, check engine light. |
| P0071 | AMBIENT AIR TEMPERATURE SENSOR PERFORMANCE | Faulty ambient air temperature sensor, sensor reading out of range. | Inaccurate temperature readings, potential issues with climate control or engine management systems. |
| P0072 | AMBIENT AIR TEMPERATURE SENSOR CIRCUIT LOW | Short circuit in the ambient air temperature sensor circuit, wiring issue, faulty sensor. | Inaccurate temperature readings, potential issues with climate control or engine management systems. |
| P0073 | AMBIENT AIR TEMPERATURE SENSOR CIRCUIT HIGH | Open circuit in the ambient air temperature sensor circuit, wiring issue, faulty sensor. | Inaccurate temperature readings, potential issues with climate control or engine management systems. |
| P007B | CHARGE AIR COOLER TEMPERATURE SENSOR CIRCUIT PERFORMANCE | Faulty charge air cooler temperature sensor, sensor reading out of range. | Reduced engine performance, decreased fuel economy, potential overheating. |
| P007C | CHARGE AIR COOLER TEMPERATURE SENSOR CIRCUIT LOW | Short circuit in the charge air cooler temperature sensor circuit, wiring issue, faulty sensor. | Reduced engine performance, decreased fuel economy, potential overheating. |
| P007D | CHARGE AIR COOLER TEMPERATURE SENSOR CIRCUIT HIGH | Open circuit in the charge air cooler temperature sensor circuit, wiring issue, faulty sensor. | Reduced engine performance, decreased fuel economy, potential overheating. |
| P007E | CHARGE AIR COOLER TEMPERATURE SENSOR CIRCUIT INTERMITTENT/ERRATIC | Intermittent fault in the charge air cooler temperature sensor circuit, wiring issue, loose connection. | Intermittent engine performance issues, fluctuating temperature readings. |
| P0087 | FUEL RAIL PRESSURE TOO LOW | Fuel pump issues, fuel filter blockage, fuel pressure regulator malfunction, fuel leaks. | Engine performance problems, lack of power, difficulty starting, stalling. |
| P0088 | FUEL RAIL PRESSURE TOO HIGH | Faulty fuel pressure regulator, fuel pressure sensor malfunction, excessive fuel delivery. | Engine performance issues, rough running, potential engine damage. |
| P00AF | TURBOCHARGER BOOST CONTROL MODULE PERFORMANCE | Faulty turbocharger boost control module, actuator issues, mechanical binding in the turbocharger. | Reduced engine power, poor acceleration, check engine light. |
| P0101 | MASS AIR FLOW SENSOR “A” CIRCUIT PERFORMANCE | Dirty or faulty mass air flow (MAF) sensor, air intake leaks, wiring issues. | Poor fuel economy, rough idle, stalling, poor acceleration, check engine light. |
| P0102 | MASS AIR FLOW SENSOR “A” CIRCUIT LOW | Short circuit in the MAF sensor circuit, wiring issue, faulty MAF sensor. | Poor fuel economy, rough idle, stalling, poor acceleration, check engine light. |
| P0103 | MASS AIR FLOW SENSOR “A” CIRCUIT HIGH | Open circuit in the MAF sensor circuit, wiring issue, faulty MAF sensor. | Poor fuel economy, rough idle, stalling, poor acceleration, check engine light. |
| P0106 | MANIFOLD ABSOLUTE PRESSURE SENSOR PERFORMANCE | Faulty manifold absolute pressure (MAP) sensor, vacuum leaks, intake manifold leaks, wiring issues. | Poor engine performance, rough idle, stalling, check engine light. |
| P0107 | MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW | Short circuit in the MAP sensor circuit, wiring issue, faulty MAP sensor. | Poor engine performance, rough idle, stalling, check engine light. |
| P0108 | MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT HIGH | Open circuit in the MAP sensor circuit, wiring issue, faulty MAP sensor. | Poor engine performance, rough idle, stalling, check engine light. |
| P0111 | INTAKE AIR TEMPERATURE SENSOR 1 PERFORMANCE | Faulty intake air temperature (IAT) sensor, sensor reading out of range, wiring issues. | Poor fuel economy, reduced engine power, check engine light. |
| P0112 | INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT LOW | Short circuit in the IAT sensor circuit, wiring issue, faulty IAT sensor. | Poor fuel economy, reduced engine power, check engine light. |
| P0113 | INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT HIGH | Open circuit in the IAT sensor circuit, wiring issue, faulty IAT sensor. | Poor fuel economy, reduced engine power, check engine light. |
| P0116 | ENGINE COOLANT TEMPERATURE SENSOR PERFORMANCE | Faulty engine coolant temperature (ECT) sensor, thermostat issues, cooling system problems, wiring issues. | Overheating, inaccurate temperature gauge readings, check engine light. |
| P0117 | ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW | Short circuit in the ECT sensor circuit, wiring issue, faulty ECT sensor. | Overheating, inaccurate temperature gauge readings, check engine light. |
| P0118 | ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT HIGH | Open circuit in the ECT sensor circuit, wiring issue, faulty ECT sensor. | Overheating, inaccurate temperature gauge readings, check engine light. |
| P0128 | THERMOSTAT RATIONALITY | Thermostat stuck open or closed, faulty ECT sensor, cooling system issues. | Engine not reaching operating temperature, overheating, check engine light. |
| P0131 | O2 SENSOR 1/1 CIRCUIT LOW | Short circuit in the O2 sensor signal circuit, wiring issue, faulty O2 sensor, rich fuel mixture. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0135 | O2 SENSOR 1/1 HEATER PERFORMANCE | Slow response from the O2 sensor heater, faulty O2 sensor. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0137 | O2 SENSOR 1/2 CIRCUIT LOW | Short circuit in the O2 sensor signal circuit, wiring issue, faulty O2 sensor, rich fuel mixture. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0138 | O2 SENSOR 1/2 CIRCUIT HIGH | Open circuit in the O2 sensor signal circuit, wiring issue, faulty O2 sensor, lean fuel mixture. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P013A | O2 SENSOR 1/2 SLOW RESPONSE – RICH TO LEAN | Slow response from the O2 sensor, faulty O2 sensor, exhaust leaks. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P013B | O2 SENSOR 1/2 SLOW RESPONSE – LEAN TO RICH | Slow response from the O2 sensor, faulty O2 sensor, exhaust leaks. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0141 | O2 SENSOR 1/2 HEATER PERFORMANCE | Slow response from the O2 sensor heater, faulty O2 sensor. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0148 | FUEL DELIVERY ERROR | Fuel injection issues, fuel pump problems, fuel pressure regulator malfunction, PCM malfunction. | Engine performance problems, rough running, misfires, difficulty starting. |
| P014C | O2 SENSOR 1/1 SLOW RESPONSE – RICH TO LEAN | Slow response from the O2 sensor, faulty O2 sensor, exhaust leaks. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P014D | O2 SENSOR 1/1 SLOW RESPONSE – LEAN TO RICH | Slow response from the O2 sensor, faulty O2 sensor, exhaust leaks. | Check engine light, reduced fuel efficiency, possible emissions test failure. |
| P0169 | WATER IN FUEL DETECTED FOR TOO LONG | Water contamination in the fuel system, faulty water-in-fuel sensor. | Check engine light, potential fuel system damage, reduced engine performance. |
| P0191 | FUEL RAIL PRESSURE SENSOR CIRCUIT PERFORMANCE | Faulty fuel rail pressure sensor, sensor reading out of range, wiring issues. | Engine performance problems, lack of power, difficulty starting. |
| P0192 | FUEL PRESSURE SENSOR LOW | Short circuit in the fuel pressure sensor circuit, wiring issue, faulty sensor. | Engine performance problems, lack of power, difficulty starting. |
| P0193 | FUEL PRESSURE SENSOR HIGH | Open circuit in the fuel pressure sensor circuit, wiring issue, faulty sensor. | Engine performance problems, lack of power, difficulty starting. |
| P0201-P0206 | FUEL INJECTOR CIRCUIT/OPEN (Cylinders 1-6) | Faulty fuel injector, wiring issue, open circuit in the injector circuit, PCM malfunction. | Engine misfires, rough running, poor fuel economy, check engine light. |
| P020A-P020F | FUEL INJECTOR PERFORMANCE (Cylinders 1-6) | Clogged or faulty fuel injector, injector driver circuit issues. | Engine misfires, rough running, poor fuel economy, check engine light. |
| P0216 | INJECTION TIMING CONTROL CIRCUIT MALFUNCTION | Injection pump issues, timing control solenoid malfunction, PCM malfunction. | Engine performance problems, rough running, poor fuel economy, check engine light. |
| P0217 | COOLANT TEMPERATURE TOO HIGH | Overheating engine, low coolant level, cooling system malfunction (radiator, fan, water pump). | Overheating warning light, temperature gauge reading high, engine damage. |
| P0218 | HIGH TEMPERATURE OPERATION ACTIVATED | Engine operating at high temperature, heavy load conditions, towing, hot ambient temperatures. | Temperature gauge reading high, potential for overheating under continued stress. |
| P0219 | ENGINE OVERSPEED | Exceeding engine RPM limits, downshifting at high speed. | Engine noise, potential engine damage, check engine light. |
| P0251 | INJECTION PUMP FUEL VALVE FEEDBACK | Injection pump malfunction, fuel valve issues, PCM malfunction. | Engine performance problems, rough running, poor fuel economy, check engine light. |
| P0253 | INJECTION PUMP FUEL CONTROL CIRCUIT LOW | Short circuit in the injection pump fuel control circuit, wiring issue, faulty pump. | Engine performance problems, lack of power, difficulty starting. |
| P0254 | INJECTION PUMP FUEL CONTROL CIRCUIT HIGH | Open circuit in the injection pump fuel control circuit, wiring issue, faulty pump. | Engine performance problems, lack of power, difficulty starting. |
| P0255 | INJECTION PUMP FUEL CONTROL CIRCUIT PERFORMANCE | Injection pump control circuit malfunction, wiring issues, PCM malfunction. | Engine performance problems, rough running, poor fuel economy, check engine light. |
| P026A | CHARGE AIR COOLER EFFICIENCY BELOW THRESHOLD | Charge air cooler leak or blockage, reduced airflow, cooling system issues. | Reduced engine power, decreased fuel economy, potential overheating. |
| P0299 | MANIFOLD PRESSURE SENSOR OUT OF RANGE LOW | Vacuum leaks, intake manifold leaks, faulty MAP sensor. | Poor engine performance, rough idle, stalling, check engine light. |
| P02E1 | DIESEL INTAKE AIR FLOW CONTROL PERFORMANCE | Diesel intake air flow control valve malfunction, actuator issues, carbon buildup. | Reduced engine performance, poor acceleration, check engine light. |
| P02E2 | DIESEL INTAKE AIR FLOW CONTROL CIRCUIT LOW | Short circuit in the diesel intake air flow control circuit, wiring issue, faulty valve. | Reduced engine performance, poor acceleration, check engine light. |
| P02E3 | DIESEL INTAKE AIR FLOW CONTROL CIRCUIT HIGH | Open circuit in the diesel intake air flow control circuit, wiring issue, faulty valve. | Reduced engine performance, poor acceleration, check engine light. |
| P02E7 | DIESEL INTAKE AIR FLOW POSITION SENSOR PERFORMANCE | Faulty diesel intake air flow position sensor, sensor reading out of range. | Reduced engine performance, poor acceleration, check engine light. |
| P02E8 | DIESEL INTAKE AIR FLOW POSITION SENSOR CIRCUIT LOW | Short circuit in the diesel intake air flow position sensor circuit, wiring issue, faulty sensor. | Reduced engine performance, poor acceleration, check engine light. |
| P02E9 | DIESEL INTAKE AIR FLOW POSITION SENSOR CIRCUIT HIGH | Open circuit in the diesel intake air flow position sensor circuit, wiring issue, faulty sensor. | Reduced engine performance, poor acceleration, check engine light. |
| P0300-P0306 | MULTIPLE/SINGLE CYLINDER MISFIRE (Cylinders 1-6) | Spark plug issues (though diesel engines don’t use spark plugs, misfires can be due to injector problems, compression issues, etc.), ignition system problems, fuel delivery issues, vacuum leaks. | Rough idle, engine shaking, loss of power, check engine light, potential catalytic converter damage. |
| P0335 | CRANKSHAFT POSITION SENSOR CIRCUIT | Faulty crankshaft position sensor, wiring issues, loose connection. | Engine stalling, difficulty starting, check engine light. |
| P0336 | CRANKSHAFT POSITION SENSOR PERFORMANCE | Faulty crankshaft position sensor, sensor reading out of range, timing issues. | Engine stalling, difficulty starting, check engine light. |
| P0340 | CAMSHAFT POSITION SENSOR CIRCUIT – BANK 1 SENSOR 1 | Faulty camshaft position sensor, wiring issues, loose connection. | Engine stalling, difficulty starting, poor engine performance, check engine light. |
| P0341 | CAMSHAFT POSITION SENSOR PERFORMANCE – BANK 1 SENSOR 1 | Faulty camshaft position sensor, sensor reading out of range, timing issues. | Engine stalling, difficulty starting, poor engine performance, check engine light. |
| P0381 | WAIT TO START LAMP INOPERATIVE | Faulty wait-to-start lamp, wiring issue, PCM malfunction. | Wait-to-start lamp not illuminating during cold starts, potential starting issues in cold weather. |
| P0400 | EGR SYSTEM FLOW MALFUNCTION | EGR valve stuck open or closed, EGR system blockage, vacuum leaks, faulty EGR sensor. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0401 | EGR SYSTEM PERFORMANCE | Restricted EGR flow, carbon buildup in EGR passages, faulty EGR valve. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0402 | EGR FLOW EXCESSIVE DETECTED | EGR valve stuck open, excessive EGR flow, faulty EGR valve position sensor. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0403 | EGR CONTROL CIRCUIT/OPEN | Faulty EGR valve solenoid, wiring issues, open circuit in the EGR control circuit. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0404 | EGR POSITION SENSOR PERFORMANCE | Faulty EGR valve position sensor, sensor reading out of range. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0405 | EGR POSITION SENSOR CIRCUIT LOW | Short circuit in the EGR position sensor circuit, wiring issue, faulty sensor. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P040B | EXHAUST GAS RECIRCULATION TEMPERATURE SENSOR 1 CIRCUIT PERFORMANCE | Faulty EGR temperature sensor, sensor reading out of range. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P040C | EXHAUST GAS RECIRCULATION TEMPERATURE SENSOR 1 CIRCUIT LOW | Short circuit in the EGR temperature sensor circuit, wiring issue, faulty sensor. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P040D | EXHAUST GAS RECIRCULATION TEMPERATURE SENSOR 1 CIRCUIT HIGH | Open circuit in the EGR temperature sensor circuit, wiring issue, faulty sensor. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0420 | CATALYST EFFICIENCY BANK 1 | Faulty catalytic converter, exhaust leaks, O2 sensor issues, engine misfires. | Check engine light, potential emissions test failure, reduced engine performance. |
| P042E | EXHAUST GAS RECIRCULATION CONTROL STUCK OPEN | EGR valve stuck open, mechanical failure in the EGR valve. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0461 | FUEL LEVEL SENSOR 1 PERFORMANCE | Faulty fuel level sensor, sensor reading out of range, wiring issues. | Inaccurate fuel gauge readings, check engine light. |
| P0462 | FUEL LEVEL SENSOR 1 CIRCUIT LOW | Short circuit in the fuel level sensor circuit, wiring issue, faulty sensor. | Inaccurate fuel gauge readings, check engine light. |
| P0463 | FUEL LEVEL SENSOR 1 CIRCUIT HIGH | Open circuit in the fuel level sensor circuit, wiring issue, faulty sensor. | Inaccurate fuel gauge readings, check engine light. |
| P046C | EGR POSITION SENSOR PERFORMANCE | Faulty EGR position sensor, sensor reading out of range. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0471 | EXHAUST PRESSURE SENSOR 1 PERFORMANCE | Faulty exhaust pressure sensor, sensor reading out of range, exhaust leaks, wiring issues. | Reduced engine performance, check engine light. |
| P0472 | EXHAUST PRESSURE SENSOR 1 LOW | Short circuit in the exhaust pressure sensor circuit, wiring issue, faulty sensor. | Reduced engine performance, check engine light. |
| P0473 | EXHAUST PRESSURE SENSOR 1 HIGH | Open circuit in the exhaust pressure sensor circuit, wiring issue, faulty sensor. | Reduced engine performance, check engine light. |
| P0480 | COOLING FAN 1 CONTROL CIRCUIT/OPEN | Faulty cooling fan relay, wiring issues, open circuit in the fan control circuit, faulty fan motor. | Engine overheating, cooling fan not operating, check engine light. |
| P0483 | COOLING FAN SPEED | Cooling fan speed sensor malfunction, fan clutch issues, wiring issues. | Engine overheating, cooling fan operating at incorrect speed, check engine light. |
| P0487 | EGR AIRFLOW THROTTLE CONTROL CIRCUIT A OPEN | Faulty EGR airflow throttle valve, wiring issues, open circuit in the control circuit. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0488 | EGR AIRFLOW THROTTLE CONTROL CIRCUIT PERFORMANCE | EGR airflow throttle valve malfunction, actuator issues, carbon buildup. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P0489 | EGR CONTROL CIRCUIT LOW | Short circuit in the EGR control circuit, wiring issue, faulty EGR valve solenoid. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P049D | EGR CONTROL POSITION EXCEEDED LEARNING LIMIT | EGR valve actuator or position sensor issues, mechanical binding in the EGR valve. | Rough idle, poor fuel economy, check engine light, potential emissions test failure. |
| P04DB | CRANKCASE VENTILATION SYSTEM DISCONNECTED | Disconnected or leaking crankcase ventilation (PCV) system hoses or components. | Engine oil leaks, vacuum leaks, check engine light. |
| P0501 | VEHICLE SPEED SENSOR 1 PERFORMANCE | Faulty vehicle speed sensor (VSS), wiring issues, sensor reading out of range. | Speedometer malfunction, cruise control issues, transmission shifting problems, check engine light. |
| P0505 | ENGINE SPEED AT IDLE – DATA ERRATIC, INTERMITTENT OR INCORRECT | Idle air control (IAC) valve issues, vacuum leaks, throttle body issues, PCM malfunction. | Unstable idle speed, stalling, check engine light. |
| P0507 | IDLE CONTROL SYSTEM RPM – HIGHER THAN EXPECTED | Vacuum leaks, IAC valve stuck open, throttle body issues. | High idle speed, check engine light. |
| P0513 | INVALID SKIM/WIN KEY | Incorrect or faulty key, security system malfunction. | Engine starting problems, security light illuminated, check engine light. |
| P0514 | BATTERY TEMPERATURE SENSOR PERFORMANCE | Faulty battery temperature sensor, sensor reading out of range, wiring issues. | Inaccurate battery temperature readings, potential charging system issues. |
| P0516 | BATTERY TEMPERATURE SENSOR CIRCUIT LOW | Short circuit in the battery temperature sensor circuit, wiring issue, faulty sensor. | Inaccurate battery temperature readings, potential charging system issues. |
| P0517 | BATTERY TEMPERATURE SENSOR CIRCUIT HIGH | Open circuit in the battery temperature sensor circuit, wiring issue, faulty sensor. | Inaccurate battery temperature readings, potential charging system issues. |
| P051B | CRANKCASE PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE | Faulty crankcase pressure sensor, sensor reading out of range, PCV system issues. | Engine oil leaks, vacuum leaks, check engine light. |
| P051C | CRANKCASE PRESSURE SENSOR CIRCUIT LOW | Short circuit in the crankcase pressure sensor circuit, wiring issue, faulty sensor. | Engine oil leaks, vacuum leaks, check engine light. |
| P051D | CRANKCASE PRESSURE SENSOR CIRCUIT HIGH | Open circuit in the crankcase pressure sensor circuit, wiring issue, faulty sensor. | Engine oil leaks, vacuum leaks, check engine light. |
| P0521 | ENGINE OIL PRESSURE SENSOR PERFORMANCE | Faulty engine oil pressure sensor, sensor reading out of range, low oil pressure, wiring issues. | Low oil pressure warning light, inaccurate oil pressure gauge readings, check engine light. |
| P0524 | ENGINE OIL PRESSURE SENSOR CIRCUIT LOW | Short circuit in the engine oil pressure sensor circuit, wiring issue, faulty sensor. | Low oil pressure warning light, inaccurate oil pressure gauge readings, check engine light. |
| P0532 | A/C PRESSURE SENSOR CIRCUIT LOW | Short circuit in the A/C pressure sensor circuit, wiring issue, faulty sensor. | A/C system malfunction, check engine light. |
| P0533 | A/C PRESSURE SENSOR CIRCUIT HIGH | Open circuit in the A/C pressure sensor circuit, wiring issue, faulty sensor. | A/C system malfunction, check engine light. |
| P0541 | INTAKE AIR HEATER CONTROL CIRCUIT 1 LOW | Short circuit in the intake air heater control circuit, wiring issue, faulty relay, intake air heater malfunction. | Difficulty starting in cold weather, check engine light. |
| P0542 | INTAKE AIR HEATER CONTROL CIRCUIT 1 HIGH | Open circuit in the intake air heater control circuit, wiring issue, faulty relay, intake air heater malfunction. | Difficulty starting in cold weather, check engine light. |
| P0545 | EXHAUST GAS TEMPERATURE SENSOR CIRCUIT LOW – BANK 1 SENSOR 1 | Short circuit in the exhaust gas temperature sensor circuit, wiring issue, faulty sensor. | Reduced engine performance, check engine light, potential emissions system issues. |
| P0546 | EXHAUST GAS TEMPERATURE SENSOR CIRCUIT HIGH – BANK 1 SENSOR 1 | Open circuit in the exhaust gas temperature sensor circuit, wiring issue, faulty sensor. | Reduced engine performance, check engine light, potential emissions system issues. |
| P0560 | BATTERY SYSTEM VOLTAGE | Battery issues, alternator problems, voltage regulator malfunction, wiring issues. | Check engine light, charging system malfunction, electrical system problems. |
| P0562 | BATTERY VOLTAGE LOW | Low battery voltage, alternator problems, parasitic drain, wiring issues. | Check engine light, charging system malfunction, electrical system problems, difficulty starting. |
| P0563 | BATTERY VOLTAGE HIGH | High battery voltage, voltage regulator malfunction, alternator overcharging. | Check engine light, charging system malfunction, electrical system problems, potential battery damage. |
| P0571 | BRAKE SWITCH 1 PERFORMANCE | Faulty brake light switch, wiring issues, brake system problems. | Brake lights not working correctly, cruise control issues, transmission shifting problems, check engine light. |
| P0572 | BRAKE SWITCH 1 STUCK ON | Faulty brake light switch, brake pedal switch adjustment issues. | Brake lights staying on, cruise control issues, transmission shifting problems, check engine light. |
| P0573 | BRAKE SWITCH 1 STUCK OFF | Faulty brake light switch, brake pedal switch adjustment issues. | Brake lights not working, cruise control inoperative, transmission shifting problems, check engine light. |
| P0580 | SPEED CONTROL SWITCH 1 CIRCUIT LOW | Short circuit in the speed control switch circuit, wiring issue, faulty switch. | Cruise control malfunction, check engine light. |
| P0581 | SPEED CONTROL SWITCH 1 CIRCUIT HIGH | Open circuit in the speed control switch circuit, wiring issue, faulty switch. | Cruise control malfunction, check engine light. |
| P0585 | SPEED CONTROL SWITCH 1/2 CORRELATION | Mismatched signals from speed control switches, faulty switches, wiring issues. | Cruise control malfunction, check engine light. |
| P0592 | SPEED CONTROL SWITCH 2 CIRCUIT LOW | Short circuit in the speed control switch circuit, wiring issue, faulty switch. | Cruise control malfunction, check engine light. |
| P0593 | SPEED CONTROL SWITCH 2 CIRCUIT HIGH | Open circuit in the speed control switch circuit, wiring issue, faulty switch. | Cruise control malfunction, check engine light. |
| P0601 | INTERNAL MEMORY CHECKSUM ERROR / INVALID | PCM internal fault, programming error, PCM failure. | Check engine light, various engine and transmission problems, potential no-start condition. |
| P0602 | CONTROL MODULE PROGRAMMING ERROR/NOT PROGRAMMED | PCM programming issue, incorrect PCM programming, PCM replacement required programming. | Check engine light, various engine and transmission problems, potential no-start condition. |
| P0604 | INTERNAL CONTROL MODULE RAM ERROR | PCM internal fault, RAM failure. | Check engine light, various engine and transmission problems, potential no-start condition. |
| P0605 | INTERNAL CONTROL MODULE ROM | PCM internal fault, ROM failure. | Check engine light, various engine and transmission problems, potential no-start condition. |
| P0606 | INTERNAL CONTROL PROCESSOR | PCM internal fault, processor failure. | Check engine light, various engine and transmission problems, potential no-start condition. |
| P0607 | ECU INTERNAL PERFORMANCE | PCM internal fault, ECU performance issue. | Check engine light, various engine and transmission problems, potential no-start condition. |
| P0613 | INTERNAL TCM | Transmission control module (TCM) internal fault. | Transmission problems, shifting issues, check engine light, transmission warning light. |
| P0615 | STARTER CONTROL CIRCUIT/OPEN | Faulty starter relay, wiring issues, open circuit in the starter control circuit, faulty starter motor. | Engine starting problems, no-start condition, check engine light. |
| P061A | ETC LEVEL 2 TORQUE PERFORMANCE | Electronic throttle control (ETC) system malfunction, throttle position sensor issues, PCM malfunction. | Reduced engine power, poor acceleration, check engine light. |
| P061C | ETC LEVEL 2 RPM PERFORMANCE | Electronic throttle control (ETC) system malfunction, throttle position sensor issues, PCM malfunction. | Unstable idle speed, poor engine performance, check engine light. |
| P0622 | GENERATOR FIELD CONTROL CIRCUIT/OPEN | Faulty alternator, wiring issues, open circuit in the generator field control circuit, voltage regulator malfunction. | Charging system malfunction, battery not charging, check engine light. |
| P0625 | GENERATOR FIELD CONTROL CIRCUIT LOW | Short circuit in the generator field control circuit, wiring issue, faulty alternator. | Charging system malfunction, battery not charging, check engine light. |
| P0626 | GENERATOR FIELD CONTROL CIRCUIT HIGH | Open circuit in the generator field control circuit, wiring issue, faulty alternator. | Charging system malfunction, battery overcharging, check engine light. |
| P0627 | FUEL PUMP CONTROL CIRCUIT | Faulty fuel pump relay, wiring issues, open circuit in the fuel pump control circuit, faulty fuel pump. | Engine starting problems, fuel delivery issues, check engine light. |
| P0628 | FUEL PUMP CONTROL CIRCUIT LOW | Short circuit in the fuel pump control circuit, wiring issue, faulty fuel pump relay. | Engine starting problems, fuel delivery issues, check engine light. |
| P0629 | FUEL PUMP CONTROL CIRCUIT HIGH | Open circuit in the fuel pump control circuit, wiring issue, faulty fuel pump relay. | Engine starting problems, fuel delivery issues, check engine light. |
| P062C | ETC LEVEL 2 MPH PERFORMANCE | Electronic throttle control (ETC) system malfunction, throttle position sensor issues, PCM malfunction. | Reduced engine power, poor acceleration, check engine light. |
| P0630 | VIN NOT PROGRAMMED IN PCM | PCM replacement without proper programming, VIN mismatch. | Check engine light, potential communication issues with other modules. |
| P0633 | SKIM SECRET KEY NOT STORED IN PCM | Security system malfunction, key programming issues. | Engine starting problems, security light illuminated, check engine light. |
| P063C | GENERATOR VOLTAGE SENSE LOW | Low voltage reading from the generator voltage sense circuit, wiring issue, faulty alternator. | Charging system malfunction, battery not charging, check engine light. |
| P063D | GENERATOR VOLTAGE SENSE HIGH | High voltage reading from the generator voltage sense circuit, wiring issue, faulty alternator. | Charging system malfunction, battery overcharging, check engine light. |
| P0642 | SENSOR REFERENCE VOLTAGE 1 CIRCUIT LOW | Short circuit in the sensor reference voltage circuit, wiring issue, faulty PCM. | Multiple sensor malfunctions, check engine light, various engine system problems. |
| P0643 | SENSOR REFERENCE VOLTAGE 1 CIRCUIT HIGH | Open circuit in the sensor reference voltage circuit, wiring issue, faulty PCM. | Multiple sensor malfunctions, check engine light, various engine system problems. |
| P0646 | A/C CONTROL CIRCUIT LOW | Short circuit in the A/C control circuit, wiring issue, faulty A/C relay, A/C system malfunction. | A/C system malfunction, check engine light. |
| P0647 | A/C CONTROL CIRCUIT HIGH | Open circuit in the A/C control circuit, wiring issue, faulty A/C relay, A/C system malfunction. | A/C system malfunction, check engine light. |
| P064C | GLOW PLUG MODULE INTERNAL PERFORMANCE | Glow plug control module internal fault. | Difficulty starting in cold weather, glow plug system malfunction, check engine light. |
| P064D | O2 SENSOR MODULE INTERNAL PERFORMANCE | O2 sensor control module internal fault. | Check engine light, emissions system malfunction, reduced fuel efficiency. |
| P0652 | SENSOR REFERENCE VOLTAGE 2 LOW | Short circuit in the sensor reference voltage circuit, wiring issue, faulty PCM. | Multiple sensor malfunctions, check engine light, various engine system problems. |
| P0653 | SENSOR REFERENCE VOLTAGE 2 HIGH | Open circuit in the sensor reference voltage circuit, wiring issue, faulty PCM. | Multiple sensor malfunctions, check engine light, various engine system problems. |
| P065A | GENERATOR SYSTEM PERFORMANCE | Alternator malfunction, charging system issues, voltage regulator problems. | Charging system malfunction, battery not charging, check engine light. |
| P0686 | POWER ENABLE CONTROL CIRCUIT LOW | Short circuit in the power enable control circuit, wiring issue, PCM malfunction. | Engine stalling, no-start condition, electrical system problems, check engine light. |
| P0691 | COOLING FAN 1 CONTROL CIRCUIT LOW | Short circuit in the cooling fan control circuit, wiring issue, faulty fan relay. | Engine overheating, cooling fan not operating, check engine light. |
| P0692 | COOLING FAN 1 CONTROL CIRCUIT HIGH | Open circuit in the cooling fan control circuit, wiring issue, faulty fan relay. | Engine overheating, cooling fan not operating, check engine light. |
| P0693 | COOLING FAN 2 CONTROL CIRCUIT LOW | Short circuit in the cooling fan control circuit, wiring issue, faulty fan relay. | Engine overheating, cooling fan not operating, check engine light. |
| P0694 | COOLING FAN 2 CONTROL CIRCUIT HIGH | Open circuit in the cooling fan control circuit, wiring issue, faulty fan relay. | Engine overheating, cooling fan not operating, check engine light. |
| P0698 | SENSOR REFERENCE VOLTAGE 3 CIRCUIT LOW | Short circuit in the sensor reference voltage circuit, wiring issue, faulty PCM. | Multiple sensor malfunctions, check engine light, various engine system problems. |
| P0699 | SENSOR REFERENCE VOLTAGE 3 CIRCUIT HIGH | Open circuit in the sensor reference voltage circuit, wiring issue, faulty PCM. | Multiple sensor malfunctions, check engine light, various engine system problems. |
| P06A4 | SENSOR REFERENCE VOLTAGE 4 CIRCUIT LOW | Short circuit in the sensor reference voltage circuit, wiring issue, faulty PCM. | Multiple sensor malfunctions, check engine light, various engine system problems. |
| P06A5 | SENSOR REFERENCE VOLTAGE 4 CIRCUIT HIGH | Open circuit in the sensor reference voltage circuit, wiring issue, faulty PCM. | Multiple sensor malfunctions, check engine light, various engine system problems. |
| P0700 | TRANSMISSION CONTROL SYSTEM (MIL REQUEST) | Transmission problem detected by the TCM, TCM requesting the check engine light to illuminate. | Check engine light, transmission problems, shifting issues, transmission warning light. |
| P0702 | TRANSMISSION CONTROL SYSTEM ELECTRICAL | Electrical fault within the transmission control system, wiring issues, TCM malfunction. | Check engine light, transmission problems, shifting issues, transmission warning light. |
| P0706 | TRANSMISSION RANGE SENSOR RATIONALITY | Faulty transmission range sensor (TRS), sensor reading out of range, transmission linkage issues. | Transmission shifting problems, incorrect gear indication, check engine light, transmission warning light. |
| P0707 | TRANSMISSION RANGE SENSOR CIRCUIT LOW | Short circuit in the TRS circuit, wiring issue, faulty sensor. | Transmission shifting problems, incorrect gear indication, check engine light, transmission warning light. |
| P0708 | TRANSMISSION RANGE SENSOR CIRCUIT HIGH | Open circuit in the TRS circuit, wiring issue, faulty sensor. | Transmission shifting problems, incorrect gear indication, check engine light, transmission warning light. |
| P0711 | TRANSMISSION TEMPERATURE SENSOR 1 PERFORMANCE | Faulty transmission temperature sensor (TFT), sensor reading out of range, overheating transmission. | Transmission overheating, incorrect temperature gauge readings, shifting problems, check engine light. |
| P0712 | TRANSMISSION TEMPERATURE SENSOR 1 LOW | Short circuit in the TFT sensor circuit, wiring issue, faulty sensor. | Transmission overheating, incorrect temperature gauge readings, shifting problems, check engine light. |
| P0713 | TRANSMISSION TEMPERATURE SENSOR 1 HIGH | Open circuit in the TFT sensor circuit, wiring issue, faulty sensor. | Transmission overheating, incorrect temperature gauge readings, shifting problems, check engine light. |
| P0714 | TRANSMISSION TEMPERATURE SENSOR INTERMITTENT | Intermittent fault in the TFT sensor circuit, wiring issue, loose connection. | Intermittent transmission overheating, fluctuating temperature readings. |
| P0716 | INPUT SPEED SENSOR 1 CIRCUIT PERFORMANCE | Faulty input speed sensor (ISS), sensor reading out of range, transmission problems, wiring issues. | Transmission shifting problems, erratic speedometer readings, check engine light, transmission warning light. |
| P0717 | INPUT SPEED SENSOR 1 CIRCUIT NO SIGNAL | Faulty ISS, wiring issues, no signal from the sensor. | Transmission shifting problems, erratic speedometer readings, check engine light, transmission warning light. |
| P0721 | OUTPUT SPEED SENSOR CIRCUIT PERFORMANCE | Faulty output speed sensor (OSS), sensor reading out of range, transmission problems, wiring issues. | Transmission shifting problems, speedometer malfunction, check engine light, transmission warning light. |
| P0722 | OUTPUT SPEED SENSOR CIRCUIT NO SIGNAL | Faulty OSS, wiring issues, no signal from the sensor. | Transmission shifting problems, speedometer malfunction, check engine light, transmission warning light. |
| P0729 | GEAR RATIO ERROR IN 6TH | Transmission mechanical problems, slipping clutch packs, internal transmission damage. | Transmission slipping in 6th gear, shifting problems, check engine light, transmission warning light. |
| P0730 | INCORRECT GEAR RATIO | Transmission mechanical problems, slipping clutch packs, internal transmission damage. | Transmission slipping, shifting problems, check engine light, transmission warning light. |
| P0731-P0736 | GEAR RATIO ERROR IN GEARS 1-5 & REVERSE | Transmission mechanical problems, slipping clutch packs, internal transmission damage. | Transmission slipping in specific gear, shifting problems, check engine light, transmission warning light. |
| P0740 | TCC OUT OF RANGE | Torque converter clutch (TCC) malfunction, solenoid issues, hydraulic problems in the transmission. | Transmission slipping, shuddering, poor fuel economy, check engine light, transmission warning light. |
| P0745 | LINE PRESSURE SOLENOID CIRCUIT | Faulty line pressure solenoid, wiring issues, solenoid circuit fault. | Transmission shifting problems, harsh shifting, check engine light, transmission warning light. |
| P0746 | PRESSURE CONTROL SOLENOID A PERFORMANCE | Faulty pressure control solenoid, solenoid performance issues, hydraulic problems in the transmission. | Transmission shifting problems, harsh shifting, check engine light, transmission warning light. |
| P0748 | PRESSURE CONTROL SOLENOID A CIRCUIT | Faulty pressure control solenoid, wiring issues, solenoid circuit fault. | Transmission shifting problems, harsh shifting, check engine light, transmission warning light. |
| P0750-P0770 | SHIFT SOLENOID CIRCUIT/PERFORMANCE (LR, A, 2C, B, OD, C, UD, D, 4C) | Faulty shift solenoid, wiring issues, solenoid circuit fault, hydraulic problems in the transmission. | Transmission shifting problems, incorrect gear selection, check engine light, transmission warning light. |
| P0776-P0798 | PRESSURE CONTROL SOLENOID PERFORMANCE/CIRCUIT (B, C) | Faulty pressure control solenoid, wiring issues, solenoid circuit fault, hydraulic problems in the transmission. | Transmission shifting problems, harsh shifting, check engine light, transmission warning light. |
| P0838 | FOUR WHEEL DRIVE (4WD) SWITCH CIRCUIT LOW | Short circuit in the 4WD switch circuit, wiring issue, faulty switch. | 4WD system malfunction, 4WD indicator light issues, check engine light. |
| P0839 | FOUR WHEEL DRIVE (4WD) SWITCH CIRCUIT HIGH | Open circuit in the 4WD switch circuit, wiring issue, faulty switch. | 4WD system malfunction, 4WD indicator light issues, check engine light. |
| P0841-P0888 | LR/2C/OD/UD/4C PRESSURE SWITCH RATIONALITY/HYDRAULIC TEST | Transmission pressure switch malfunction, hydraulic pressure issues in the transmission. | Transmission shifting problems, harsh shifting, check engine light, transmission warning light. |
| P0890 | SWITCHED BATTERY | Battery voltage issues, wiring problems, PCM malfunction. | Electrical system problems, check engine light, potential no-start condition. |
| P0930-P0935 | BTSI CONTROL CIRCUIT LOW/HIGH, HYDRAULIC/LINE PRESSURE SENSOR | Brake transmission shift interlock (BTSI) system issues, hydraulic pressure sensor malfunction, line pressure sensor issues. | Shifting problems, inability to shift out of park, transmission performance issues, check engine light. |
| P0944 | LOSS OF HYDRAULIC PUMP PRIME | Transmission hydraulic pump malfunction, low transmission fluid level, hydraulic leaks. | Transmission shifting problems, loss of drive, check engine light, transmission warning light. |
| P0952-P0983 | AUTOSTICK/SHIFT SOLENOID CIRCUIT LOW/HIGH (ERS, A, B, C, D, 4C) | Autostick system issues, shift solenoid circuit problems, wiring issues. | Autostick malfunction, manual shifting problems, check engine light, transmission warning light. |
| P1001-P1794 | Various Codes | Refer to detailed descriptions for each specific code above. | Refer to detailed descriptions for each specific code above. |
| P2000-P2A01 | Various Codes | Refer to detailed descriptions for each specific code above. | Refer to detailed descriptions for each specific code above. |
| U0001-U1601 | CAN BUS & Communication Codes | Communication network issues between modules (PCM, TCM, ABS, etc.), wiring problems, module malfunctions. | Check engine light, communication errors, various system malfunctions, potential no-start condition. |
Note: This list is not exhaustive, and specific codes and their meanings can sometimes vary slightly depending on the exact model year, trim, and engine options of your 2012 Ram 2500 diesel. Always consult your vehicle’s repair manual or a professional mechanic for precise diagnosis and repair procedures.
Troubleshooting Your 2012 Ram 2500 Diesel OBD2 Codes
When your check engine light comes on and you retrieve an OBD2 code, it’s important to approach troubleshooting systematically:
- Record the Code: Use an OBD2 scanner to read and record all trouble codes present. Note down the codes and their descriptions.
- Research the Code: Consult this guide and other reliable sources to understand the possible causes and symptoms associated with the code.
- Visual Inspection: Perform a visual inspection of the affected system. Check for any obvious issues like loose wires, disconnected hoses, leaks, or damaged components. For example, if you have a MAF sensor code (P0101, P0102, P0103), inspect the MAF sensor connector and air intake system for leaks.
- Basic Troubleshooting: Some codes may point to simple fixes. For instance, a loose gas cap can trigger evaporative emission system codes. Ensure your gas cap is tightened properly. For MAF sensor codes, try cleaning the MAF sensor.
- Professional Diagnosis: Many OBD2 codes require specialized tools and expertise to diagnose accurately. If you’re not comfortable working on your vehicle or if the code indicates a complex issue, it’s best to consult a certified mechanic.
When to Seek Professional Help
While some minor issues can be resolved with basic troubleshooting, it’s crucial to seek professional help in the following situations:
- Unfamiliar Codes: If you are unsure about the meaning of a code or how to proceed with diagnosis.
- Complex Systems: Codes related to the transmission, ABS, or engine management systems often require specialized knowledge and equipment.
- Persistent Codes: If you’ve attempted basic troubleshooting and the code returns, it indicates a more significant underlying problem.
- Performance Issues: If the check engine light is accompanied by drivability problems like rough running, stalling, loss of power, or transmission shifting issues.
Conclusion
Understanding OBD2 codes is a valuable skill for any 2012 Ram 2500 diesel owner. This guide provides a comprehensive resource to help you decipher those codes and take the first steps toward diagnosing and resolving issues. However, remember that accurate diagnosis and repair often require professional expertise. Don’t hesitate to consult a qualified mechanic to ensure your Ram 2500 diesel continues to run reliably and efficiently. Addressing check engine light issues promptly can prevent more significant and costly repairs down the road, keeping your truck on the road and performing at its best.
