Faulty Signal

Faulty signal

Checking components, intake system

Hint: This diagnostic trouble code can be caused by a damaged mass air flow sensor.

Check that lambda adaptations are within the specified normal values.
Incorrect lambda adaptations can indicate a faulty mass air flow (MAF) sensor.

Hint: Use the adaptations for the mass air flow (MAF) sensor and leak flow (parameter read out) to determine how much the system has adapted.

An adaptation on one or both parameters that is less than approximately 0.85 indicates blocked crankcase ventilation and/or a dirty electronic throttle module (ETM).
Adaptations greater than approximately 1.15 indicate a (smaller) air leak somewhere in the intake system.

Note! Even extremely small air leaks can cause this diagnostic trouble code (DTC) to be stored.

Check that the intake air temperature (IAT) sensor and boost pressure sensor are correctly installed. Check for air leakage around the components.
Check the crankcase ventilation for blockage. In particular check the positive crankcase ventilation (PCV) valve on turbocharged engines.

Hint: Indications of a blocked positive crankcase ventilation (PCV) valve include contamination or oil on components in the intake system.

Remedy as necessary.

Other information
- Air leakage in the intake system, checking, B5244T5, B5254T2 Air Leaks in the Intake System, Checking
- Throttle body (TB), cleaning Procedures
- Mass air flow (MAF) sensor, replacing Service and Repair






Continue - Verification

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Verification




Verification

Verification

Hint: After carrying out the repair, check that the fault has been remedied.








- Ignition off.
- Reinstall the connectors, components etc.
- Ignition on.
- Read off and make a note of the adaptation value.
- Start the engine. Increase the engine speed (RPM) a couple of times.
- Read off the adaptation value and check that the adaptation value approaches 1.









Does the adaptation value approach 1?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - Fault Found

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Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - FAULT-TRACING FAILED

No - Attempt New Test

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FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - intake system

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