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TuningBot DTC Database · v4.37.15

P1138 VAG - Diagnostic Trouble Code (2 interpretations)

Manufacturer-specific interpretation for VAG. All interpretations of P1138

P · PowertrainFuelOBD2

What P1138 means

P1138
Long term fuel trim, idling, Bank 2 - system too lean VAG · fuel Data confidence 62%

The control module detected that the air-fuel mixture stayed leaner than the target despite full corrective control (Long term fuel trim, idling, Bank 2 - system). This is the manufacturer-specific definition used by Audi.

Possible causes

  • Fuel pressure/pump
  • injector(s)
  • intake/ exhaust leak
  • AIR system
  • hose leak
Applies to Audi
P1138
Long term fuel trim, idling, system too lean VAG · fuel Data confidence 80%

The control module detected that the air-fuel mixture stayed leaner than the target despite full corrective control (Long term fuel trim, idling, system). This is the manufacturer-specific definition used by Volkswagen.

Possible causes

  • Fuel pressure/pump
  • injector(s)
  • intake/ exhaust leak
  • AIR system
  • hose leak
Applies to Volkswagen

Related and nearby codes

How to read P1138

P

Powertrain: engine, transmission and driveline systems.

1

Manufacturer-defined range: the meaning can differ between brands.

138

Specific fault index within the subsystem.

Frequently asked questions about P1138

What does P1138 mean?

Diagnostic Trouble Code (2 interpretations). The control module detected that the air-fuel mixture stayed leaner than the target despite full corrective control (Long term fuel trim, idling, Bank 2 - system). This is the manufacturer-specific definition used by Audi.

Is P1138 generic or manufacturer-specific?

P1138 is a manufacturer-specific code. In this database it is documented for: VAG. The same number can mean something different on other brands.

Can TuningBot remove P1138 at file level?

If the fault logic lives in the ECU calibration, yes: our DTC Removal file service disables the specific fault entry. Checksum correction is not included: it is a separate, optional service. Not sure whether your case qualifies? Request a free assessment and our engineers will check your ECU file.

Other file services

ECU tuningStage 1 dyno results for VAG engines See the results →

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