Signal Too Low

Signal too low

Checking the fuel injection system
Check the intake system for air leakage.

Hint: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Check the exhaust system for leakage.
Check the fuel pressure and residual pressure.
Check that the oil level is within the minimum and maximum markings.
Check the viscosity of the engine oil by reading off the short-term fuel trim with the engine running. Plug the crankcase ventilation and read off the short-term fuel trim again. The value must be more or less unchanged.
Remedy as necessary.

Other information:
- Check for air leaks in the intake system Air Leaks in the Intake System, Checking
- Checking for air leakage in the exhaust system Air Leakage Exhaust System, Check





Was a fault detected?

Yes - Verification

No - Checking the mass air flow (MAF) sensor

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Checking the mass air flow (MAF) sensor
Test drive the car for approximately 10 minutes.
Read off the correction factor of the mass air flow (MAF) sensor. The value must be between 0.8 and 1.2.

Note! There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information
- .






Continue - Verification

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Verification




Verification

Verification

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








- Ignition off
- Reconnect the connectors, reinstall components etc.
- Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: Verifying repairs Verifying Repairs
- Connect VCT2000 to the data link connector (DLC) without switching off the engine.

Note! If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated.

Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list.
Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.





Is the function OK?

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 the fuel injection system

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