Flow Too Low. Permanent Fault
Flow too low. Permanent fault
Checking connector
- Ignition off
- Check mass air flow (MAF) sensor connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Reinstall components, reconnect connectors etc.
- Ignition on.
- Check that the air flow corresponds, the value should be approximately 0 kg/h with engine switched off.
- Start the engine and read off the air flow which should be approximately 14 kg/h when idling.
- Increase the engine speed (RPM) and check that the air flow increases with increased engine speed.
If the values correspond it means that the cause of the fault has been loose connections in the connector.
Other information
- To access/replace the Mass Air Flow (MAF) sensor, see Mass air flow sensor (MAF), replacing, B5234T9, B5244T7 Air Flow Meter/Sensor.
Is the function OK?
Yes - Fault has been remedied
No - Checking component and wiring
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Checking component and wiring
Check that there is no air leakage in the intake system or damage to hoses etc.
Check signal cable between engine control module (ECM) #A22 (#A22) and engine control module (ECM) #5 for an open circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check signal cable between engine control module (ECM) #A22 (#A22) and mass air flow (MAF) sensor #5 for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check power supply cable between engine control module (ECM) #39 (#A39) and mass air flow (MAF) sensor #4 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check power supply cable between engine control module (ECM) #A70 (#A70) and mass air flow (MAF) sensor #2 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Remedy as necessary.
Other information
- Connecting the breakout box/accessing the control module, see Connecting the breakout box, B5234T9, B5244T7 Connecting The Breakout Box.
- To access/replace the mass air flow (MAF) sensor, see Mass air flow sensor (MAF), replacing, B5234T9, B5244T7 Air Flow Meter/Sensor.
- With the ignition on and mass air flow (MAF) sensor connector connected the voltage at mass air flow (MAF) sensor #2 should be approximately Ubat, mass air flow (MAF) sensor #3 should be ground and mass air flow (MAF) sensor #5 should be approximately 1 volt.
- For information about signals, see Signal specification Signal Specifications.
Continue - Verification
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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 - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Checking connector
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