Navigating car troubles can be frustrating, especially when the check engine light illuminates in your 1996 Jeep Grand Cherokee. Fortunately, modern vehicles like the Grand Cherokee are equipped with an On-Board Diagnostics system, specifically OBD2 in 1996 models, to help pinpoint issues. This system generates codes that, while seemingly cryptic, are your first step towards understanding and resolving your vehicle’s problems.
This guide, created by the experts at techcarusa.com, serves as your comprehensive resource for deciphering 1996 Jeep Grand Cherokee Obd2 Codes. We’ll break down what these codes mean, helping you understand potential issues and guide you towards effective solutions.
Understanding OBD2 and Your 1996 Jeep Grand Cherokee
OBD2, or On-Board Diagnostics II, is a standardized system implemented in vehicles sold in the United States from 1996 onwards. It monitors various components and systems within your car, from the engine and transmission to emissions control systems. When the system detects a problem outside of normal parameters, it generates a Diagnostic Trouble Code (DTC), commonly known as an OBD2 code, and illuminates the check engine light.
For owners of a 1996 Jeep Grand Cherokee, understanding OBD2 codes is invaluable. Instead of relying solely on a mechanic for initial diagnosis, you can use an OBD2 scanner to retrieve these codes yourself. This empowers you to:
- Gain Initial Insight: OBD2 codes provide a starting point for understanding the nature of the problem.
- Communicate Effectively with Mechanics: Knowing the codes beforehand can help you have a more informed conversation with your mechanic.
- Potentially Resolve Minor Issues: Some codes might indicate simple fixes you can handle yourself.
However, it’s crucial to remember that OBD2 codes are diagnostic aids, not definitive diagnoses. A code points towards a potential issue, but further investigation is usually required to pinpoint the root cause and implement the correct repair.
1996 Jeep Grand Cherokee OBD2 Codes List
Below is a detailed list of OBD2 codes specific to the 1996 Jeep Grand Cherokee. This list covers powertrain codes (P-codes), which are the most common and relate to engine and transmission issues. These codes are categorized numerically for easy navigation.
P0100 – P0199: Air and Fuel Metering
- P0107 – Manifold Absolute Pressure/Barometric Pressure Circuit Low Input: Indicates the MAP sensor is reading lower than expected, possibly due to a vacuum leak or sensor malfunction.
- P0108 – Manifold Absolute Pressure/Barometric Pressure Circuit High Input: Signals the MAP sensor is reading higher than expected, potentially due to a sensor fault or wiring issue.
- P0112 – Intake Air Temperature Circuit Low Input: The IAT sensor is reporting a lower than expected air temperature, which could be a sensor or wiring problem.
- P0113 – Intake Air Temperature Circuit High Input: The IAT sensor is reporting a higher than expected air temperature, suggesting a sensor or wiring issue.
- P0117 – Engine Coolant Temperature Circuit Low Input: Indicates the engine coolant temperature sensor is reading low, possibly due to a sensor or wiring issue.
- P0118 – Engine Coolant Temperature Circuit High Input: The engine coolant temperature sensor is reading high, potentially due to a sensor or wiring problem.
- P0121 – Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance Problem: The TPS is not performing as expected within its range, potentially indicating a sensor malfunction or throttle body issue.
- P0122 – Throttle/Pedal Position Sensor/Switch A Circuit Low Input: The TPS is reading lower voltage than expected, possibly due to a sensor fault or wiring problem.
- P0123 – Throttle/Pedal Position Sensor/Switch A Circuit High Input: The TPS is reading higher voltage than expected, suggesting a sensor fault or wiring issue.
- P0125 – Insufficient Coolant Temperature for Closed Loop Fuel Control: The engine has not reached the required temperature for the system to enter closed loop operation, potentially due to a thermostat issue.
- P0129 – Catalyst Monitor Slow O2 Sensor (Bank 1 Sensor 2): The downstream oxygen sensor is responding slower than expected when monitoring the catalyst efficiency.
- P0131 – Left Bank and Upstream O2 Sensor Voltage Shorted to Ground: The upstream oxygen sensor on Bank 1 is shorted to ground.
- P0132 – Left Upstream O2 Sensor Shorted to Voltage: The upstream oxygen sensor on Bank 1 is shorted to voltage.
- P0133 – Upstream O2 Sensor Circuit Slow Response (Bank 1 Sensor 1): The upstream oxygen sensor on Bank 1 is responding slowly, which could indicate a sensor issue.
- P0135 – O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1): The heater circuit for the upstream oxygen sensor on Bank 1 is malfunctioning.
- P0137 – Left Bank Downstream or Downstream and Pre-Catalyst O2 Sensor Voltage Shorted to Ground: The downstream oxygen sensor on Bank 1 is shorted to ground.
- P0138 – Left Bank Downstream or Downstream and Pre-Catalyst O2 Sensor Shorted to Voltage: The downstream oxygen sensor on Bank 1 is shorted to voltage.
- P0141 – Downstream, Left Bank Downstream or Pre-Catalyst O2 Sensor Heater Failure: The heater circuit for the downstream oxygen sensor on Bank 1 has failed.
- P0152 – Left Upstream O2 Sensor Slow Response: The upstream oxygen sensor on Bank 1 is responding slowly.
- P0162 – Charging System Voltage Too Low: The charging system voltage is lower than expected.
- P0171 – Right Rear (or Just) Fuel System Too Lean: The fuel system is running lean, indicating too much air or not enough fuel in the mixture.
- P0172 – Left Bank or Fuel System Too Rich: The fuel system is running rich, indicating too much fuel or not enough air in the mixture.
P0200 – P0299: Injector Circuit
- P0201 – Injector No. 1 Control Circuit: Malfunction in the control circuit for injector number 1.
- P0202 – Injector No. 2 Control Circuit: Malfunction in the control circuit for injector number 2.
- P0203 – Injector No. 3 Control Circuit: Malfunction in the control circuit for injector number 3.
- P0204 – Injector No. 4 Control Circuit: Malfunction in the control circuit for injector number 4.
- P0205 – Injector No. 5 Control Circuit: Malfunction in the control circuit for injector number 5.
- P0206 – Injector No. 6 Control Circuit: Malfunction in the control circuit for injector number 6.
- P0207 – Injector No. 7 Control Circuit: Malfunction in the control circuit for injector number 7.
- P0208 – Injector No. 8 Control Circuit: Malfunction in the control circuit for injector number 8.
P0300 – P0399: Ignition System or Misfire
- P0300 – Random/Multiple Cylinder Misfire Detected: Random misfires are occurring across multiple cylinders.
- P0301 – Cylinder No. 1 – Misfire Detected: Misfire detected in cylinder number 1.
- P0302 – Cylinder No. 2 – Misfire Detected: Misfire detected in cylinder number 2.
- P0303 – Cylinder No. 3 – Misfire Detected: Misfire detected in cylinder number 3.
- P0304 – Cylinder No. 4 – Misfire Detected: Misfire detected in cylinder number 4.
- P0305 – Cylinder No. 5 – Misfire Detected: Misfire detected in cylinder number 5.
- P0306 – Cylinder No. 6 – Misfire Detected: Misfire detected in cylinder number 6.
- P0307 – Cylinder No. 7 – Misfire Detected: Misfire detected in cylinder number 7.
- P0308 – Cylinder No. 8 – Misfire Detected: Misfire detected in cylinder number 8.
- P0320 – No Crank Reference Signal PCM: The PCM is not receiving a crank reference signal.
- P0340 – No Cam Signal at PCM: The PCM is not receiving a camshaft position sensor signal.
- P0351 – Ignition Coil No. 1 Primary Circuit: Malfunction in the primary circuit of ignition coil number 1.
P0400 – P0499: Auxiliary Emission Controls
- P0420 – Left Bank Catalytic Converter or Just Catalytic Converter Efficiency Failure: The catalytic converter efficiency is below the acceptable threshold.
- P0441 – Evaporative Purge Flow Monitor Failure: The evaporative emission system purge flow is not functioning correctly.
- P0442 – Evaporative Emission Control System Leak Detected (Small Leak): A small leak has been detected in the evaporative emission control system.
- P0443 – Evap Purge Solenoid Circuit: Malfunction in the evaporative purge solenoid circuit.
- P0455 – Evaporative Emission Control System Leak Detected (Gross Leak): A large leak has been detected in the evaporative emission control system.
- P0460 – Fuel Level Unit No Change Over Miles: The fuel level sensor is not registering changes over a distance driven.
- P0462 – Fuel Level Sending Unit Voltage Too Low: The fuel level sending unit is reporting a lower voltage than expected.
- P0463 – Fuel Level Sending Unit Voltage Too High: The fuel level sending unit is reporting a higher voltage than expected.
P0500 – P0599: Vehicle Speed Controls and Idle Control System
- P0500 – No Vehicle Speed Sensor Signal: The vehicle speed sensor is not sending a signal.
- P0505 – Idle Air Control Motor Circuits: Malfunction in the idle air control motor circuits.
P0600 – P0699: Computer Output Circuit
- P0600 – PCM/Serial Communication Link Malfunction: A malfunction in the PCM or serial communication link.
- P0601 – Internal Controller Failure: Internal failure within the PCM.
- P0622 – Generator Field Not Switching Properly: The generator field is not switching as expected.
- P0645 – A/C Clutch Relay Circuit: Malfunction in the A/C clutch relay circuit.
P0700 – P0799: Transmission
- P0711 – Transmission Fluid Temperature Sensor, No Temperature Rise After Start: The transmission fluid temperature sensor is not detecting a temperature increase after starting.
- P0712 – Transmission Fluid Temperature Sensor Voltage Too Low: The transmission fluid temperature sensor is reporting a lower voltage than expected.
- P0713 – Transmission Fluid Temperature Sensor Voltage Too High: The transmission fluid temperature sensor is reporting a higher voltage than expected.
- P0720 – Low Output Speed Sensor RPM Above 15 MPH: The output speed sensor is reading low RPM above 15 MPH.
- P0740 – Torque Converter Clutch, No RPM Drop at Lockup: The torque converter clutch is not causing an RPM drop when locking up.
- P0743 – Torque Converter Clutch Solenoid/Trans Relay Circuits: Malfunction in the torque converter clutch solenoid or transmission relay circuits.
- P0748 – Governor Pressure Solenoid Control/Trans Relay Circuits: Malfunction in the governor pressure solenoid control or transmission relay circuits.
- P0751 – Overdrive Switch Pressed (LO) More Than 5 Minutes: The overdrive switch has been pressed in the LO position for more than 5 minutes.
- P0753 – Trans 3-4 Shift Solenoid/Trans Relay Circuits: Malfunction in the 3-4 shift solenoid or transmission relay circuits.
- P0783 – 3-4 Shift Solenoid, No RPM Drop @ 3-4 Shift: The 3-4 shift solenoid is not causing an RPM drop during a 3-4 shift.
P1100 – P1199: Fuel and Air Metering and Auxiliary Emission Controls
- P1195 – Catalyst Monitor Slow O2 Sensor (Bank 1 Sensor 1): The upstream oxygen sensor is responding slower than expected when monitoring the catalyst.
- P1197 – Catalyst Monitor Slow O2 Sensor (Bank 1 Sensor 2): The downstream oxygen sensor is responding slower than expected when monitoring the catalyst.
P1200 – P1299: Idle Control System and Vehicle Speed Controls
- P1281 – Engine is Cold Too Long: The engine is taking too long to reach operating temperature.
- P1282 – Fuel Pump Relay Control Circuit: Malfunction in the fuel pump relay control circuit.
- P1294 – Target Idle Not Reached: The engine idle speed is not reaching the target idle speed.
- P1296 – No 5 Volts to MAP Sensor: The MAP sensor is not receiving a 5-volt reference signal.
- P1297 – No Change in MAP from Start to Run: The MAP sensor reading is not changing from engine start to run.
P1300 – P1399: Ignition System or Misfire
- P1388 – Auto Shutdown Relay Control Circuit: Malfunction in the auto shutdown relay control circuit.
- P1389 – No ASD Relay Output Voltage at PCM: The PCM is not receiving output voltage from the ASD relay.
- P1391 – Intermittent Loss of CMP or CKP: Intermittent loss of camshaft position (CMP) or crankshaft position (CKP) sensor signal.
- P1398 – Misfire Adaptive Numerator at Limit or No Crank Sensor Learn: The misfire adaptive numerator is at its limit, or no crank sensor learn has occurred.
P1400 – P1499: Auxiliary Emission Controls
- P1486 – EVAP Leak Monitor Pinched Hose or Obstruction Found: A pinched hose or obstruction has been found in the EVAP leak monitor system.
- P1492 – Battery Temp Sensor Voltage Too High: The battery temperature sensor is reporting a higher voltage than expected.
- P1493 – Battery Temp Sensor Voltage Too Low: The battery temperature sensor is reporting a lower voltage than expected.
- P1494 – Leak Detection Pump Pressure Switch or Mechanical Fault: A fault with the leak detection pump pressure switch or a mechanical fault in the leak detection pump.
- P1495 – Leak Detection Pump Solenoid Circuit: Malfunction in the leak detection pump solenoid circuit.
P1500 – P1599: Vehicle Speed Controls and Idle Control System
- P1594 – Charging System Voltage Too High: The charging system voltage is higher than expected.
- P1595 – Speed Control Solenoid Circuits: Malfunction in the speed control solenoid circuits.
- P1596 – Speed Control Switch Always High: The speed control switch is always reporting a high signal.
- P1597 – Speed Control Switch Always Low: The speed control switch is always reporting a low signal.
P1600 – P1699: Computer Output Circuit
- P1683 – Speed Control Power Circuit: Malfunction in the speed control power circuit.
- P1696 – PCM Failure EEPROM Write Denied: The PCM has failed to write to the EEPROM (Electrically Erasable Programmable Read-Only Memory).
- P1698 – PCM Failure EEPROM Write Denied: The PCM has failed to write to the EEPROM.
P1700 – P1799: Transmission
- P1756 – Governor Pressure Not Equal to Target @ 15-20 PSI: The governor pressure is not equal to the target pressure at 15-20 PSI.
- P1757 – Governor Pressure Above 3 PSI in Gear with 0 MPH: The governor pressure is above 3 PSI while in gear and at 0 MPH.
- P1762 – Governor Pressure Sensor Offset Volts Too Low or High: The governor pressure sensor offset voltage is too low or too high.
- P1763 – Governor Pressure Sensor Volts Too High: The governor pressure sensor voltage is too high.
- P1764 – Governor Pressure Sensor Volts Too Low: The governor pressure sensor voltage is too low.
- P1765 – Trans 12 Volts Supply Relay Control Circuit: Malfunction in the transmission 12-volt supply relay control circuit.
- P1899 – P/N Switch Stuck in Park or in Gear: The Park/Neutral switch is stuck in Park or in Gear.
Troubleshooting Common OBD2 Codes on a 1996 Jeep Grand Cherokee
While this list provides the meaning of each code, troubleshooting often requires a systematic approach. Here are general steps to follow when you encounter OBD2 codes on your 1996 Jeep Grand Cherokee:
- Record the Code: Use an OBD2 scanner to retrieve and record all present codes. Note down the exact code number(s).
- Research the Code: Use this guide or other reputable online resources to understand the potential meaning of the code and the affected system.
- Visual Inspection: Check for obvious signs of problems related to the code, such as loose wires, damaged sensors, vacuum leaks, or fluid leaks.
- Component Testing: Depending on the code, you might need to test specific components like sensors, solenoids, or relays. A multimeter and the Jeep Grand Cherokee repair manual can be helpful here.
- Consult a Professional: If you are unsure about troubleshooting or repair, or if the problem seems complex, it’s always best to consult a certified mechanic.
When to Seek Professional Help
Diagnosing and repairing car problems can be challenging. While OBD2 codes offer valuable information, they don’t always provide the full picture. It’s advisable to seek professional help in the following situations:
- Multiple Codes: If you have multiple codes, it can indicate a more complex issue or interconnected problems.
- Unfamiliar Codes: If you are unfamiliar with the code or the related system, professional diagnosis is recommended.
- Persistent Codes: If you clear the code and it returns quickly, it indicates an ongoing problem that needs expert attention.
- Safety Concerns: If the code is related to critical systems like brakes, airbags, or steering, seek immediate professional help.
By understanding 1996 Jeep Grand Cherokee OBD2 codes and using this guide, you are better equipped to maintain your vehicle and address potential issues effectively. Remember, this information is for educational purposes and should be used responsibly. Always prioritize safety and consult professionals when needed.
