Diagnostic Aids

An intermittent problem can be caused by misrouted harness, rubbed-through wire insulation or broken wire inside insulation. Also, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Go to next step.
2. Turn ignition on. Review and record FAILURE RECORDS data on scan tool. Operate vehicle within FAILURE RECORDS conditions. If DTC P0103 is set, go to next step. If DTC P0103 is not set, check for an intermittent problem. See DIAGNOSTIC AIDS .
3. Start engine and allow it to reach normal operating temperature. With engine at idle, monitor MAF FREQUENCY parameter on scan tool. If display is greater than 9500 Hz, go to next step. If display is 9500 Hz or less, go to step  7.
4. Turn ignition off. Disconnect MAF sensor harness connector. Start engine and let idle. Using scan tool, monitor MAF FREQUENCY parameter. If display is zero Hz, go to next step. If display is not zero Hz, go to step  6.
5. Replace MAF sensor. Retest system. If DTC P0103 resets, replace PCM. If DTC P0103 does not reset, repair is complete.
6. Check MAF sensor harness for incorrect routing near high voltage components (solenoids, relays or motors). Repair as necessary. If MAF sensor harness is okay, replace PCM. Retest system.
7. With engine at idle, monitor MAF FREQUENCY parameter on scan tool. Snap throttle wide open and release while observing scan tool display. If display reading was greater than 40 g/s, go to step  5. If display reading was not as specified, replace PCM. Retest system.