Diesel Data: Automotive Repair

DTC Troubleshooting




DTC Troubleshooting: P0102, 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/PCM.�

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

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

Is the fuse OK?

YES -

Go to step 5.

NO -

Repair short in the wire between the MAF sensor/IAT sensor and the No. 4 ACG (10 A) fuse. Also replace the No. 4 ACG (10 A) fuse, then go to step 21.

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. 4 ACG (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 15.

NO -

Go to step 10.

10. Jump the SCS line with the HDS.

11. Disconnect ECM/PCM connector C (22P).

12. Check for continuity between ECM/PCM connector terminal C22 and body ground.





Is there continuity?

YES -

Repair short in the wire between the ECM/PCM (C22) and the MAF sensor/IAT sensor, then go to step 20.

NO -

Go to step 13.

13. Connect MAF sensor/IAT sensor 5P connector terminal No. 1 to body ground with a jumper wire.






14. Check for continuity between ECM/PCM connector terminal C22 and body ground.





Is there continuity?

YES -

Go to step 26.

NO -

Repair open in the wire between the ECM/PCM (C22) and the MAF sensor/IAT sensor, then go to step 20.

15. Reconnect the MAF sensor/IAT sensor 5P connector.

16. Start the engine. Hold the engine speed at 2,000 rpm without load (A/T in P or N, M/T in neutral).

17. Measure the voltage between ECM/PCM connector terminal C22 and body ground.





Is there about 1.5 V?

YES -

Go to step 25.

NO -

Go to step 18.

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

19. Replace the MAF sensor/IAT sensor Service and Repair.

20. Reconnect all connectors.

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

22. Reset the ECM/PCM with the HDS.

23. Do the ECM/PCM idle learn procedure ECM/PCM Idle Learn Procedure.

24. Check for Pending or Confirmed 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/PCM, then go to step 1.

NO -

Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.�

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

26. Reconnect all connectors.

27. Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM.

28. Check for Pending or Confirmed 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/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then recheck. If the ECM/PCM was substituted, go to step 1.

NO -

If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM ECM/PCM Replacement (A/T). If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.�