Diagnostic trouble code P1137 is a manufacturer-specific powertrain fault code. Because it is manufacturer-specific, its exact definition depends entirely on the vehicle make, model, and application.
Exact vehicle application must be verified before diagnosis. The code identifies a detected condition in a specific subsystem, but further testing is required to identify the root cause.
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Key Takeaways
- P1137 is a manufacturer-specific code, meaning its definition varies between automakers like Volkswagen, Audi, and General Motors.
- On VW and Audi applications, it indicates a long-term fuel trim additive bank 1 system too rich condition.
- On some other applications, it points to an oxygen sensor circuit or heater circuit fault.
- Diagnosis requires verifying the exact factory definition and testing the relevant fuel trim or sensor circuits.
P1137 Code Description and Implications
Because P1137 is manufacturer-specific, there is no single universal definition. This trouble code identifies a detected condition, but the exact monitored system depends on the vehicle make and model.
Some Volkswagen and Audi applications: P1137 indicates a “Long Term Fuel Trim Additive Bank 1 System Too Rich” fault. The engine control module detects that the idle fuel adaptation has reached its maximum rich limit.
Some other applications: P1137 may indicate an oxygen sensor heater circuit fault or a lack of switching in the Bank 1 Sensor 2 oxygen sensor circuit.
Common Causes of the P1137 Code
The underlying cause depends entirely on the verified factory definition for the specific vehicle application.
For VW and Audi applications, possible causes include a failing mass airflow sensor, a leaking fuel injector, a stuck open EVAP purge valve, or excessive fuel pressure.
For applications monitoring the oxygen sensor circuit, causes may involve a failing Bank 1 Sensor 2 oxygen sensor, damaged sensor wiring, poor electrical connections, or an exhaust leak near the sensor.
Symptoms Associated With P1137
Symptoms vary widely depending on the underlying system fault and the vehicle manufacturer.
On VW and Audi applications with a fuel trim fault, symptoms can include rough idling, decreased fuel efficiency, a rich exhaust smell, and an illuminated Check Engine Light.
On applications with an oxygen sensor fault, symptoms may include poor engine performance, failed emissions tests, and an illuminated Check Engine Light.
Diagnosing the P1137 Trouble Code
Diagnosis must begin by confirming the exact factory definition for the specific make, model, and year.
For VW and Audi applications, technicians inspect the EVAP purge valve for sticking, test the mass airflow sensor readings, and check for leaking fuel injectors or high fuel pressure.
For applications monitoring the oxygen sensor, technicians inspect the exhaust for leaks, test the sensor heater and signal circuits, and verify the sensor operation using live data.
Repairing the P1137 Issue
Repairs must follow confirmed diagnosis based on the specific vehicle application.
If a fuel trim fault is confirmed on a VW or Audi application, the confirmed failed component such as the EVAP purge valve, fuel injector, or mass airflow sensor must be replaced or repaired.
If an oxygen sensor fault is confirmed, the Bank 1 Sensor 2 oxygen sensor or the damaged wiring harness must be replaced or repaired.
Cost Considerations for P1137 Repairs
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Replacing an EVAP purge valve or cleaning a mass airflow sensor involves minimal parts cost and standard labor times.
Conversely, replacing fuel injectors or an electronic oxygen sensor requires specific component replacement and potential adaptation procedures using a scan tool.
Prevention Strategies for Future Occurrences
Some electrical and mechanical failures cannot be reliably prevented.
Using high-quality fuel and replacing fuel filters at recommended intervals can help protect fuel injectors and maintain proper fuel system operation.
Inspecting exposed engine wiring harnesses and exhaust components for damage can help prevent electrical faults and false air intrusion.
Troubleshooting Tips and Best Practices
Never assume P1137 is a universal oxygen sensor code. Always verify the exact definition for the specific vehicle before purchasing parts.
Do not ignore related codes. A fuel trim fault may appear alongside other mixture codes, while an oxygen sensor fault may appear alongside catalyst efficiency codes.
Check for technical service bulletins applicable to your exact vehicle application, as manufacturers frequently release updated components or revised software calibrations for recurring faults.
More OBD-II Codes
| P1136 | P1138 | P0172 | P1145 |
| P1135 | P1139 | P0171 | P1146 |
| P1134 | P1140 | P1131 | P1147 |
| P1133 | P1141 | P1144 | P1148 |
| P1132 | P1142 | P1151 | P1149 |
| P1130 | P1143 | P1153 | P1150 |
Frequently Asked Questions
Is P1137 a generic or manufacturer-specific code?
No. P1137 is a manufacturer-specific code. Its exact definition varies significantly between automakers, so the factory service information for the specific vehicle must be consulted.
Can I drive my car with a P1137 code?
It depends on the application. If P1137 indicates a rich fuel condition, fuel efficiency will drop. If it is an oxygen sensor fault, emissions may increase.
Will disconnecting the battery clear the P1137 code?
Disconnecting the battery may temporarily clear the code, but it does not repair the underlying electrical or mechanical fault. It also resets readiness monitors and fuel trims.
Can a vacuum leak cause a P1137 code?
Usually, a vacuum leak causes a lean condition. However, on some applications, a stuck open EVAP purge valve acts like a vacuum leak pulling fuel vapors, causing a rich condition.
Does P1137 always mean the oxygen sensor is bad?
No. While a failing oxygen sensor is a cause on specific applications, the code can also indicate a fuel trim fault caused by a failing MAF sensor or leaking injector.
What Should You Do About the P1137 Code?
Confirm the exact factory definition and diagnostic procedure for your specific vehicle application. Because P1137 is manufacturer-specific, identifying whether it relates to a fuel trim additive fault or an oxygen sensor circuit is mandatory.
Follow the applicable manufacturer diagnostic steps to test the relevant system and components. Once the root cause is confirmed, complete the necessary repairs and verify that the system operates correctly and the code does not return.
