DTC Troubleshooting

DTC Troubleshooting: P0102

DTC P0102: MAF Sensor Circuit Low Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview

1. Turn the ignition switch to ON (II), and wait 2 seconds.

2. Check the MAF SENSOR in the DATA LIST with the HDS.

Is about 0 gm/s, or 0.1 V or less indicated?
YES - Go to step 3.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the ECM.


3. Turn the ignition switch to LOCK (0).

4. Check the No. 3 ALTERNATOR (10 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?
YES - Go to step 4.

NO - Repair short in the wire between the MAF sensor/IAT sensor and the No. 3 ALTERNATOR (10 A) fuse. Also replace the No. 3 ALTERNATOR (10 A) fuse, then go to step 20.


5. Disconnect the MAF sensor/IAT sensor 5P connector.

6. Turn the ignition switch to ON (II).

7. Measure the voltage between MAF sensor/IAT sensor 5P connector terminal No. 3 and body ground.

Is there battery voltage?
YES - Go to step 8.

NO - Repair open in the wire between the No. 3 ALTERNATOR (10 A) fuse and the MAF sensor/IAT sensor, then go to step 20.






8. Turn the ignition switch to LOCK (0).

9. Measure the resistance between MAF sensor/IAT sensor 5P connector terminal No. 1 and body ground.

Is there 190-210 kOhms?
YES - Go to step 14.

NO - Go to step 10.






10. Jump the SCS line with the HDS.

11. Disconnect ECM connector B (44P).

12. Check for continuity between ECM connector terminal B30 and body ground.

Is there continuity?
YES - Repair short in the wire between the ECM (B30) and the MAF sensor/IAT sensor, then go to step 21.

NO - Go to step 13.






13. Check for continuity between MAF sensor/IAT sensor 5P connector terminal No. 1 and ECM connector terminal B30.

Is there continuity?
YES - Go to step 26.

NO - Repair open in the wire between the ECM (B30) and the MAF sensor/IAT sensor, then go to step 21.






14. Substitute a known-good MAF sensor/IAT sensor. Service and Repair

15. Reconnect all connectors.

16. Turn the ignition switch to ON (II).

17. Clear the DTC with the HDS.

18. Start the engine. Hold the engine speed at 2,000 rpm without load (in neutral).

19. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0102 indicated?
YES - Go to step 27.

NO - Replace the original MAF sensor/IAT sensor, Service and Repair then go to step 20.


20. Turn the ignition switch to LOCK (0).

21. Reconnect all connectors.

22. Turn the ignition switch to ON (II).

23. Reset the ECM with the HDS.

24. Do the ECM idle learn procedure. ECM Idle Learn Procedure

25. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0102 indicated?
YES - Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the ECM, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


26. Reconnect all connectors.

27. Update the ECM if it does not have the latest software, ECM Update or substitute a known-good ECM. Initial Inspection and Diagnostic Overview

28. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0102 indicated?
YES - Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then recheck. If the ECM was substituted, go to step 1.

NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. Service and Repair If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.