Flow Too Low - Permanent Fault

ECM-1300 MASS AIR FLOW (MAF) SENSOR
FLOW TOO LOW - PERMANENT FAULT

Checking connector



- Ignition off
- Check mass air flow (MAF) sensor connector for contact resistance and oxidation according to [1][2]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, Mass Air Flow (MAF) Sensor, Replacing

Is the function OK?
Yes - Testing Complete.
No - Continue below.


Checking component and wiring






Check that there is no air leakage in the intake system or damage to hoses etc. according to Check For Air Leaks In the Intake System

Check signal cable between engine control module (ECM) #A22 (#A22) and engine control module (ECM) #5 for an open circuit according to [1][2]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 [1][2]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 [1][2]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 [1][2]Checking Wiring and Terminals. Permanent Fault

Remedy as necessary.

Other information
- Connecting the breakout box/accessing the control module, Connecting the Breakout Box (ECM)
- To access/replace the Mass Air Flow (MAF) sensor, Mass Air Flow (MAF) Sensor, Replacing
- With the ignition on and mass air flow (MAF) sensor connector connected the voltage at mass air flow (MAF) sensor #2 should be approximately U(bat), 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 Diagnostic Parameters and Pinout Values. Signal Description, ME7, B5XX4T


Verification



Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Reinstall connectors, components etc.
- Ignition on.
- Check that the air flow corresponds, the value should be approximately 0 kg/h (0 lb/h) with engine switched off.
- Start the engine and read off the air flow which should be approximately 14 kg/h (30.86 lb/h) when idling.
- Increase the engine speed (RPM) and check that the air flow increases with increased engine speed.

Do the values agree?
Yes - Testing Complete.
No - Continue below.


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.