Flow Too Low

Flow too low

Checking components and wiring
Check the mass air flow (MAF) sensor connector. Check for contact resistance and oxidation.
Check for air leakage in the intake system and for damage to hoses etc.
Check the inside of the throttle body (TB). Check for contamination. When the throttle body (TB) is contaminated, the air flow to the engine is impaired and diagnostic trouble code (DTCs) or fault symptoms can occur.
Clean the throttle body (TB) if needed.
Check the power supply cable between system relay terminal #5 and mass air flow (MAF) sensor terminal #2. Check for an open-circuit.
Check the signal cable between engine control module (ECM) terminal #A22 (#A22) and mass air flow (MAF) sensor terminal #5. Check for a short-circuit to ground.
Check the power supply cable between engine control module (ECM) terminal #A39 (#A39) and mass air flow (MAF) sensor terminal #4. Check for an open-circuit.

Hint: With the ignition on and the mass air flow (MAF) sensor connector connected the voltage at mass air flow (MAF) sensor terminal #2 must be approximately U bat.

Remedy as necessary.

Other information
- To connect the breakout box and access the control module, see Connecting the breakout box, B5244T5, B5254T2 Connecting the Breakout Box
- Checking for air leakage in the intake system Checking for Air Leakage in the Intake System
- Throttle body (TB), cleaning Procedures
- Mass air flow (MAF) sensor, replacing Service and Repair
- For information about signals on 5 cylinder engines, see Signal specification Signal Description / Specification
- For information about signals on 6 cylinder engines, see Signal specification Signal Description / Specification
- Checking wiring and terminals Checking Wiring And Terminals













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
- Check that the air flow is correct. The value must be approximately 0 kg/h with the engine switched off
- Start the engine. Read off the air flow. The value may vary by between 12-20 kg/h at idle speed, depending on the engine load and temperature. The value may be in excess of 20 kg/h if the engine is cold
- Increase the engine speed (RPM) and check that the air flow increases with increased engine speed.









Are the values correct?

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 - Checking components and wiring

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