Signal Too Low

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

Diagnostic Trouble Code (DTC) status ECM-1300 Intake Air Temperature (IAT) Sensor - Signal too low
Reading DTC status ECM-1300



Note! When Reading the DTC status, other stored Diagnostic Trouble Codes (DTCs) and their status Will be listed.

- Read the DTC status. Check the status of the relevant Diagnostic Trouble Code (DTC).

Was the status of the relevant Diagnostic Trouble Code (DTC) displayed as permanent?
Yes - Continue below.
No - Signal Too Low - Intermittent Fault


Checking connector



- Ignition off.
- Check Mass Air Flow (MAF) sensor connector for contact resistance and oxidation.

Remedy as necessary.

Other information:
- To access/replace the mass air flow (MAF) sensor, Mass Air Flow (MAF) Sensor, Replacing


Checking connector



- Ignition off.
- Reinstall components, reconnect connectors etc.
- Start the engine and let it idle.
- Read the Mass Air Flow (MAF) sensor signal.

Check that the signal is within its permitted range. Voltage at idling speed should be 1.5-1.8 V.
If signal is now OK this indicates that the fault was caused by poor contact in the connector.

Other information:
- To access/replace the mass air flow (MAF) sensor, Mass Air Flow (MAF) Sensor, Replacing
- Mass Air Flow (MAF) sensor, table values Mass Air Flow (MAF) Sensor

Is the signal OK?
Yes - Skip to "Verification"
No - Continue below.


Checking wiring and components



Check Mass Air Flow (MAF) sensor resistance. For actual voltage levels Mass Air Flow (MAF) Sensor

Check signal cable between control module # A22 (# A22) and Mass Air Flow (MAF) sensor terminal 2 for a short- circuit to ground according to [1][2]Checking Wiring and Terminals. Permanent Fault and for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault

Check ground lead between control module connector # A60 (# B2) and Mass Air Flow (MAF) sensor connector terminal 5 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault

Remedy as necessary.

Other information:
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace the mass air flow (MAF) sensor, Mass Air Flow (MAF) Sensor, Replacing
- For information about signals, Pinout Values and Diagnostic Parameters


Verification



Hint:After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Reconnect connectors, reinstall components.
- Start the engine and let it idle.
- Read the Mass Air Flow (MAF) sensor signal. The Mass Air Flow (MAF) sensor signal should be approximately 1.5-1.8V at idling speed.

Is the mass air flow (MAF) sensor signal OK?
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.