P1139 Volkswagen Code - Long Term Fuel Trim Add. Fuel B2 System Too Rich
Quick Answer
The diagnostic trouble code P1139 for Volkswagen vehicles indicates that the Long Term Fuel Trim Additive Fuel Bank 2 System is too rich. Common causes include Faulty oxygen sensor, Vacuum leak in the intake system, Dirty or clogged fuel injectors. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1139 Volkswagen indicates Long Term Fuel Trim Add. Fuel B2 System Too Rich.
- Common causes
- Common causes include Faulty oxygen sensor, Vacuum leak in the intake system, Dirty or clogged fuel injectors.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P1139 Volkswagen Description
The diagnostic trouble code P1139 for Volkswagen vehicles indicates that the Long Term Fuel Trim Additive Fuel Bank 2 System is too rich. Fuel trim refers to the adjustment made by the engine control module (ECM) to the air-fuel mixture to maintain optimal combustion. In this case, the ECM is detecting that the fuel mixture in bank 2 of the engine is too rich, meaning there is an excess of fuel compared to the amount of air present.
Common Causes of P1139 Volkswagen
- Faulty oxygen sensor
- Vacuum leak in the intake system
- Dirty or clogged fuel injectors
- Issues with the fuel pressure regulator
- Malfunctioning mass airflow sensor
Symptoms of P1139 Volkswagen
- Decreased fuel efficiency
- Rough idle or stalling
- Engine misfires
- Strong fuel odor from exhaust
- Check Engine Light illuminated
How to Fix P1139 Volkswagen
- Diagnose the specific cause of the rich fuel mixture by performing a thorough inspection of the oxygen sensor, intake system, fuel injectors, fuel pressure regulator, and mass airflow sensor.
- Address any identified issues, such as replacing a faulty oxygen sensor, repairing a vacuum leak, cleaning or replacing clogged fuel injectors, or replacing a malfunctioning mass airflow sensor.
- Clear the trouble code from the ECM memory and reset the Long Term Fuel Trim values.
- Test drive the vehicle to ensure the issue has been resolved and that the fuel mixture is within the correct parameters.
- If necessary, perform a final scan to verify that the code has not returned and that the system is functioning properly.
Cost to Fix P1139 Volkswagen
The cost of repairing a P1139 code can vary depending on the specific cause of the issue and the necessary repairs. In general, the cost of parts can range from $100 to $500, with labor costs adding an additional $100 to $300. Overall, the total repair cost for addressing a rich fuel mixture in bank 2 of a Volkswagen vehicle could range from $200 to $800. It is advisable to consult with a trusted mechanic or dealership to get a more accurate estimate based on your vehicle's make and model, as well as the local labor rates in your area.
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