Operation CHARM: Car repair manuals for everyone.

DC10 - Check For Intermittent Sensor



Continuous Memory Diagnostic Trouble Code (DTC) 157 indicates the Mass Air Flow (MAF) sensor signal went below 0.4 volt sometime during the last 80 warm-up cycles.

Possible causes:

- Poor continuity in MAF sensor harness or connectors.

- Intermittent open or short in MAF sensor or harness.

- Damaged MAF sensor.

- Idle Air Control (IAC) system failure (at closed throttle position).

- Clear continuous memory. Clearing Diagnostic Trouble Codes

- Start engine and idle for 5 to 10 minutes.

- Vehicle in "PARK" or "NEUTRAL".

- Suddenly goose (greater than a half second) the throttle, approaching 1500 rpm.

- Allow to return to idle.

- Then, goose the throttle again, approaching 1500 rpm.

- Key "ON", engine "OFF".

- Run Self-Test to observe Continuous Memory DTCs.

- Is Continuous Memory DTC 157 present?

Yes -- Go to DC13. DC13 - Air Leak at MAF Sensor

No -- Go to DC11. DC11 - Monitor MAF Circuit Under Simulated Road Shock