Diesel Data: Automotive Repair

DTC Troubleshooting




DTC Troubleshooting: P0103, P0103

DTC P0103:

MAF Sensor Circuit High 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 202 gm/s or 4.89 V or more 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. Jump the SCS line with the HDS.

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

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

7. Connect MAF sensor/IAT sensor 5P connector terminal No. 2 to body ground with a jumper wire.






8. Check for continuity between ECM/PCM connector terminal C21 and body ground.





Is there continuity?

YES -

Go to step 9.

NO -

Repair open in the wire between the ECM/PCM (C21) and the MAF sensor/IAT sensor, then go to step 15.

9. Reconnect ECM/PCM connector C (22P).

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

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

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





Is there about 1.5 V?

YES -

Go to step 20.

NO -

Go to step 13.

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

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

15. Reconnect all connectors.

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

17. Reset the ECM/PCM with the HDS.

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

19. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0103 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.�

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

21. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0103 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.�