DTC P0101: Mass Airflow Sensor Performance
- Check tachometer operation on instrument cluster. If tachometer operation is okay, go to next step. If tachometer operation is not okay, check for possible crankshaft position sensor fault. See DTC P0335: CRANKSHAFT POSITION SENSOR CIRCUIT .
- Check throttle function and operation of throttle position sensor. See DTC P0121: THROTTLE POSITION SENSOR "A" PERFORMANCE , DTC P0122: THROTTLE POSITION SENSOR "A" VOLTAGE LOW & DTC P0222: THROTTLE POSITION SENSOR "B" VOLTAGE LOW and DTC P0123: THROTTLE POSITION SENSOR "A" VOLTAGE HIGH & DTC P0223: THROTTLE POSITION SENSOR "B" VOLTAGE HIGH . Repair as necessary and retest system. If throttle operation is okay, go to next step.
- Check air intake system. Ensure air cleaner is not obstructed. Check air meter-to-throttle body seal and engine breather-to-inlet duct. Repair as necessary and retest system. If air intake system is okay, go to next step.
- Turn ignition off. Disconnect ECM harness connector EM12 and Mass Airflow (MAF) sensor harness connector. Check continuity of Green/Yellow wire between ECM harness connector EM12 terminal No. 13 and MAF sensor harness connector terminal No. 2. See Figure and Fig 1 . If continuity exists, go to next step. If continuity does not exist, repair open in Green/Yellow wire and retest system.
- Check continuity of Black/Yellow wires between MAF sensor harness connector terminal No. 5 and ECM harness connector EM12 terminals No. 18 and 19. If continuity exists, go to next step. If continuity does not exist, repair open in Black/Yellow wire(s) and retest system.
- Measure resistance between ECM harness connector EM12 terminal No. 13 (Green/Yellow wire) and terminals No. 18 (Black/Yellow wire) and No. 19 (Black/Yellow wire). If resistance is more than 10 megohms, go to next step. If resistance is 10 megohms or less, repair short circuit and retest system.
- Turn ignition on. Measure voltage between ECM harness connector EM12 terminal No. 13 (Green/Yellow wire) and terminals No. 18 (Black/Yellow wire) and No. 19 (Black/Yellow wire). If voltage is zero volts, reconnect ECM harness connector EM12 and go to next step. If voltage is more than zero volts, repair short to voltage and retest system.CAUTION: DO NOT short jumper wires.
- Turn ignition off. Ensure MAF sensor is disconnected. Connect jumper wire between MAF sensor harness connector terminal No. 1 (White/Blue wire) and MAF sensor terminal No. 1. Connect a second jumper wire between MAF sensor harness connector terminal No. 5 (Black/Yellow wire) and MAF sensor terminal No. 5. Start and run engine at idle. Connect voltmeter between jumper wires. If output voltage is .7-1.7 volts with engine at normal operating temperature, system is okay. If output voltage is not .7-1.7 volts, replace MAF sensor.