Is your 1999 Honda CRV’s check engine light illuminated? Don’t panic. This light, also known as the Malfunction Indicator Lamp (MIL), is your car’s way of telling you something needs attention. Understanding how to read the check engine light, specifically using the OBD2 system in your ’99 CRV, can save you time and money. This guide will walk you through the process, explain what the codes mean, and provide you with the knowledge to take informed action.
Understanding OBD-II and Diagnostic Trouble Codes (DTCs)
Since 1996, all cars sold in the United States, including your 1999 Honda CRV, are equipped with an On-Board Diagnostics II (OBD-II) system. This standardized system monitors various aspects of your vehicle’s performance, particularly emissions-related systems. When the system detects an issue, it triggers the check engine light and stores a Diagnostic Trouble Code (DTC) in the car’s computer.
What is OBD-II?
OBD-II is an international standard that ensures consistency in vehicle diagnostics. Before OBD-II, manufacturers had their own proprietary diagnostic systems, making it difficult for mechanics and car owners to understand and address issues without specialized tools. OBD-II standardized everything from the diagnostic codes themselves to the physical connector used to access the vehicle’s computer. This standardization allows for easier and more universal vehicle diagnostics.
What are DTCs?
DTCs are five-digit alphanumeric codes that pinpoint the area of the problem within your vehicle. The structure of a DTC is as follows:
- First character: Indicates the system affected:
- P – Powertrain (engine, transmission)
- B – Body (interior, airbags, etc.)
- C – Chassis (brakes, suspension, steering)
- U – Network/Communication
- Second character: Indicates if the code is generic (0) or manufacturer-specific (1). For basic check engine light issues, you’ll likely encounter generic codes.
- Third character: Specifies the subsystem:
- 1 – Fuel and Air Metering
- 2 – Fuel and Air Metering (Injector Circuit)
- 3 – Ignition System or Misfire
- 4 – Auxiliary Emission Controls
- 5 – Vehicle Speed Controls and Idle Control System
- 6 – Computer Output Circuit
- 7 – Transmission
- 8 – Transmission
- Last two characters: Indicate the specific fault within that subsystem.
Understanding this structure can help you interpret the codes and better understand the potential problem.
Reading the Check Engine Light on Your 1999 Honda CRV
There are two primary methods to retrieve the DTCs from your 1999 Honda CRV: using a paperclip (a legacy method) or using a modern OBD2 scanner. While the paperclip method is mentioned in some older contexts, using an OBD2 scanner is significantly easier, more accurate, and provides more information.
Using an OBD2 Scanner (Recommended Method)
The most straightforward way to read the check engine light codes on your 1999 CRV is by using an OBD2 scanner. These scanners are readily available online or at auto parts stores and range in price from basic code readers to more advanced diagnostic tools.
Steps to use an OBD2 Scanner:
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Locate the OBD2 Port: In your 1999 Honda CRV, the OBD2 port is typically located under the driver’s side dashboard, near the steering column. Refer to your owner’s manual if you are unsure of the exact location.
Alt text: Location of the OBD2 port under the dashboard of a vehicle.
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Plug in the Scanner: Turn off your Honda CRV’s ignition. Plug the OBD2 scanner into the port.
Alt text: Connecting an OBD2 scanner to the diagnostic port in a car.
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Turn Ignition to “ON” Position (Engine Off): Turn the ignition key to the “ON” position, but do not start the engine. This provides power to the car’s computer and the OBD2 scanner.
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Follow Scanner Instructions: Turn on the OBD2 scanner and follow the manufacturer’s instructions to read codes. Most scanners have a “Read Codes” or “Diagnostic Codes” option.
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Record the DTCs: The scanner will display the DTC(s) stored in your car’s computer. Write down these codes exactly as they appear. Some scanners will also provide a brief description of the code.
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Interpret the Codes: Once you have the DTC(s), you can use online resources or code lists (like the one provided later in this article) to understand what each code signifies.
Using the Paperclip Method (For Reference Only – Not Recommended)
The paperclip method is an older technique that involves using a paperclip to bridge two terminals in the OBD2 port and counting the check engine light flashes to decipher codes. This method is generally not recommended for modern OBD2 systems as it can be unreliable and potentially risky if not performed correctly. However, for informational purposes, here’s a brief overview based on the original article:
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Locate the OBD2 Port: As described above.
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Insert Paperclip: Carefully insert a paperclip to bridge the specified terminals in the OBD2 port. The original article shows images, but specific terminals might vary and could be misapplied. Incorrectly bridging terminals can damage your vehicle’s electrical system.
Alt text: Illustration of using a paperclip to bridge terminals in an OBD2 port for reading check engine light codes.
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Turn Ignition to “ON” Position (Engine Off): As described above.
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Count Check Engine Light Flashes: The check engine light will blink in patterns. Long flashes represent ’10’ and short flashes represent ‘1’. Count the flashes to determine the codes. For example, one long flash followed by three short flashes would be code 13.
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Interpret the Codes: Refer to a Honda CEL code list to understand the meaning of the numerical codes.
Again, using an OBD2 scanner is the safer, more accurate, and much easier method for reading check engine light codes on your 1999 Honda CRV.
Common OBD-II Codes for 1999 Honda CRV
Here is a comprehensive list of OBD-II codes and corresponding CEL codes relevant to your 1999 Honda CRV. This list is compiled from the original article and aims to provide a starting point for understanding your DTCs.
| MIL Code | OBDII Code | Description of Code |
|---|---|---|
| 1 | P0131 | Primary HO2S Circuit Low Voltage (Sensor 1) |
| 1 | P0132 | Primary HO2S Circuit High Voltage (Sensor 1) |
| 3 | P0107 | MAP Circuit Low Input |
| 3 | P0108 | MAP Circuit High Input |
| 4 | P0335 | CKP Sensor Circuit Low Input |
| 4 | P0336 | CKP Sensor Range/Performance |
| 5 | P0106 | MAP Circuit Range Or Performance |
| 5 | P1128 | MAP Lower Than Expected |
| 5 | P1129 | MAP Higher Than Expected |
| 6 | P0117 | ECT Circuit Low Input |
| 6 | P0118 | ECT Circuit High Input |
| 7 | P0122 | TP Sensor Circuit Low Input |
| 7 | P0123 | TP Sensor Circuit High Input |
| 7 | P1121 | Throttle Position Lower Than Expected |
| 7 | P1122 | Throttle Position Higher Than Expected |
| 8 | P1359 | CKP/TDC Sensor Connector Disconnection |
| 8 | P1361 | TDC Sensor Intermittent Interruption |
| 8 | P1362 | TDC Sensor No Signal |
| 9 | P1381 | Cylinder Position Sensor Intermittent Interruption |
| 9 | P1382 | Cylinder Position Sensor No Signal |
| 10 | P0111 | IAT Sensor Circuit Range/Performance |
| 10 | P0112 | IAT Sensor Circuit Low Input |
| 10 | P0113 | IAT Sensor Circuit High Input |
| 12 | P1491 | EGR Valve Lift Insufficient Detected |
| 12 | P1498 | EGR Valve Lift Sensor High Voltage |
| 13 | P1106 | BARO Circuit Range/Performance |
| 13 | P1107 | BARO Circuit Low Input |
| 13 | P1108 | BARO Circuit High Input |
| 14 | P0505 | ICS Malfunction |
| 14 | P1508 | IAC Valve Circuit Failure |
| 14 | P1509 | IAC Valve Circuit Failure |
| 14 | P1519 | Idle Air Control Valve Circuit Failure |
| 17 | P0500 | VSS Circuit Malfunction (M/T) |
| 17 | P0501 | VSS Circuit Range/Performance (A/T) |
| 20 | P1297 | Electrical Load Detector Circuit Low Input |
| 20 | P1298 | Electrical Load Detector Circuit High Input |
| 21 | P1253 | VTEC System Malfunction |
| 22 | P1257, P1258, P1259 | VTEC System Malfunction |
| 23 | P0325 | KS Circuit Malfunction |
| 30 | P1655 | SEAF/SEFA/TMA/TMB Signal Line Failure |
| 30 | P1681 | A/T FI Signal A Low Input |
| 30 | P1682 | A/T FI Signal A High Input |
| 31 | P1686 | A/T FI Signal B Low Input |
| 31 | P1687 | A/T FI Signal B High Input |
| 34 | P0560 | Powertrain Control Module (PCM) Backup Voltage Circuit Low Voltage |
| 41 | P0135 | Front HO2S Heater Circuit Fault (Sensor 1) |
| 41 | P1166 | Primary HO2S (No. 1) Heater System Electrical |
| 41 | P1167 | Primary HO2S (No. 1) Heater System |
| 45 | P0171 | System Too Lean |
| 45 | P0172 | System Too Rich |
| 48 | P1162 | Primary HO2S (No. 1) Circuit Malfunction |
| 48 | P1168 | Primary HO2S (No. 1) LABEL Low Input |
| 48 | P1169 | Primary HO2S (No. 1) LABEL High Input |
| 54 | P1336 | CSF Sensor Intermittent Interruption |
| 54 | P1337 | CSF Sensor No Signal |
| 58 | P1366 | TDC Sensor No. 2 Intermittent Interruption |
| 58 | P1367 | TDC Sensor No 2 Signal |
| 61 | P0133 | Primary HO2S Circuit Slow Response (Sensor 1) |
| 61 | P1149 | Primary HO2S (Sensor 1) Circuit Range/Performance Problem |
| 61 | P1163 | Primary HO2S (No. 1) Circuit Slow Response |
| 61 | P1164 | Primary HO2S (No. 1) Circuit Range/Performance |
| 61 | P1165 | Primary HO2S (No. 1) Circuit Range/Performance |
| 63 | P0137 | Secondary HO2S Circuit Low Voltage (Sensor 2) |
| 63 | P0138 | Secondary HO2S Circuit High Voltage (Sensor 2) |
| 63 | P0139 | Secondary HO2S Circuit Slow Response (Sensor 2) |
| 65 | P0141 | Secondary HO2S Heater Circuit Fault (Sensor 2) |
| 67 | P0420 | Catalyst System Efficiency Below Threshold |
| 70 | P0700, P0715, P0720, P0725, P0730, P0740, P0753, P0758, P0763, P0780, P1660, P1705, P1706, P1738, P1739, P1753, P1758, P1768, P1773, P1785, P1786, P1790, P1791, P1792, P1793, P1794, P1870, P1873, P1879, P1885, P1886, P1888, P1890, P1891 | A/T Concerns |
| 71 | P0301 | Misfire Cyl. 1 Or Random Misfire |
| 72 | P0302 | Misfire Cyl. 2 Or Random Misfire |
| 73 | P0303 | Misfire Cyl. 3 Or Random Misfire |
| 74 | P0304 | Misfire Cyl. 4 Or Random Misfire |
| 75 | P0305 | Misfire Cyl. 5 Or Random Misfire |
| 76 | P0306 | Misfire Cyl. 6 Or Random Misfire |
| 80 | P0401 | EGR Insufficient Flow Detected |
| 86 | P0116 | ECT Circuit Range Or Performance |
| 90 | P1456 | EVAP Emission Control System Leak Detected (Fuel Tank System) |
| 90 | P1457 | EVAP Emission Control System Leak Detected (Control Canister System) |
| 91 | P0451 | Fuel Tank Pressure Sensor Range/Performance |
| 91 | P0452 | Fuel Tank Pressure Sensor Circuit Low Input |
| 91 | P0453 | Fuel Tank Pressure Sensor Circuit High Input |
| 92 | P0441 | EVAP Emission Control System Improper Purge Flow |
| 92 | P1459 | EVAP Emission Purge Flow Switch Malfunction |
| — | P0300 | Random Misfire |
| — | P1486 | Thermostat Range/Performance Problem |
| — | P1607 | ECM/PCM Internal Circuit Failure A |
| — | P1676 | FPTDR Signal Line Failure |
| — | P1678 | FPTDR Signal Line Failure |
| 71–74 | P1300 | Multiple Cylinder Misfire Detected |
Note: This table is for informational purposes and is based on data available at the time of the original article (2006). Always consult a reliable and updated source for the most accurate and current code definitions. Websites like www.obd-codes.com can be helpful resources.
What to Do After Reading the Code?
Reading the check engine light code is just the first step. Once you have the DTC, you need to investigate further to diagnose and fix the underlying issue.
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Research the Code: Use the code and the description from the table or an online resource to understand the potential problem.
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Basic Troubleshooting: Depending on the code, you can perform some basic checks yourself. For example:
- Loose Gas Cap (EVAP codes): Ensure your gas cap is properly tightened.
- Sensor Connections: Check for loose or disconnected sensor wires or connectors related to the code.
- Fluid Levels: Check coolant and oil levels, especially if the code relates to temperature sensors.
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Consider “Limp Home” Mode: Some OBD-II codes can trigger “limp home” mode, which reduces engine power to prevent further damage. The original article lists sensors that can cause limp mode (MAF, IAT, TPS, ECT, CMP, BARO, CKF, EGO). If your CRV is performing poorly, limp mode might be active.
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Decide on Repair Action: Based on your research and basic checks, you have a few options:
- DIY Repair: If you are mechanically inclined and the issue seems straightforward (e.g., replacing a sensor), you might attempt the repair yourself.
- Seek Professional Help: For complex issues or if you are not comfortable working on your car, it’s best to take your 1999 Honda CRV to a qualified mechanic or Honda dealership.
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Clear the Code (Optional and with Caution): Some OBD2 scanners allow you to clear the DTCs and turn off the check engine light. However, clearing the code without fixing the underlying problem is not recommended. The light will likely reappear. Clearing codes is generally only advised after you have diagnosed and repaired the issue to confirm the problem is resolved. Note that in some cases, the check engine light will turn off automatically after a repair if the system no longer detects the fault.
Conclusion
Understanding how to read the check engine light on your 1999 Honda CRV using OBD2 is a valuable skill for any car owner. By using an OBD2 scanner and this guide, you can gain insights into your vehicle’s health, potentially saving money on unnecessary diagnostic fees, and making informed decisions about car maintenance and repair. Remember to prioritize safety and seek professional help when needed. Regularly addressing check engine light issues helps keep your 1999 Honda CRV running smoothly and efficiently for years to come.
