DTC P0102: MAF Sensor Circuit Low Input
NOTE:
DTC is set when Mass Airflow (MAF) sensor signal is too low. For connector terminal wire colors, see appropriate wiring diagram in
WIRING DIAGRAMS article. For component locations, see appropriate illustration under COMPONENT LOCATIONS in
SELF-DIAGNOSTICS - INTRODUCTION article.
NOTE:
Before replacing any component, ensure all connectors at component and ECM are clean and tight. After making any repairs, disconnect ECM harness connector for 10 seconds, connect ECM harness connector and retest system. It is necessary to generate an ECM readiness code if ECM memory is cleared, battery voltage is disconnected or ECM is disconnected. Engine Control Module (ECM) and Throttle Valve Control Module (TVCM) must also be matched when either component is replaced or when TVCM is removed and reinstalled.
- Check air induction system for leaks. If problem exists, repair as necessary. If problem does not exist, go to next step.
- Turn ignition off. Disconnect MAF sensor harness connector. Disconnect Engine Control Module (ECM) harness connector. Connect Test Box (VAG 1598/18) to ECM harness connector, but not to ECM. Turn ignition on. Using a fused jumper wire, connect sockets No. 1 and 6 at test box. Measure voltage between terminals No. 1 and 3 at MAF sensor harness connector. See Fig 1. Voltage should be at least 11.5 volts. If voltage is as specified, go to step 5. If voltage is not as specified, go to next step.
- Turn ignition off. Measure resistance between ground and terminal No. 1 at MAF sensor harness connector. Resistance should be less than 1.5 ohms. If resistance is as specified, go to next step. If resistance is not as specified, repair open in MAF sensor ground circuit.
- Measure resistance between terminal No. 1 at MAF sensor harness connector and socket No. 1 at test box. Resistance should be less than 1.5 ohms. If resistance is not as specified, repair open in wiring between MAF sensor and ECM. If resistance is as specified, repair open wiring between fuel pump relay and MAF sensor.
- Using a fused jumper wire, connect terminals No. 1 and 2 at MAF sensor harness connector. Measure resistance between sockets No. 1 and 16 at test box. Resistance should be less than 1.5 ohms. If resistance is as specified, remove jumper wire and go to next step. If resistance is not as specified, repair open in wiring between MAF sensor and ECM.
- Using a fused jumper wire, connect terminals No. 1 and 4 at MAF sensor harness connector. Measure resistance between sockets No. 1 and 17 at test box. Resistance should be less than 1.5 ohms. If resistance is as specified, remove jumper wire and go to next step. If resistance is not as specified, repair open in wiring between MAF sensor and ECM.
- Measure resistance between sockets No. 16 and 17 at test box. Resistance should be infinite. If resistance is as specified, go to next step. If resistance is not as specified, repair circuits shorted to each other between MAF sensor and ECM.
- Replace MAP sensor with known-good unit. Clear DTCs. Test drive vehicle and recheck for DTCs. If DTC P0102 resets, replace ECM. If DTC P0102 does not reset, replace MAF sensor.