DTC Troubleshooting

DTC Troubleshooting: P0651

DTC P0651: Sensor Reference Voltage B Malfunction

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), or press the engine start/stop button to select the ON mode.

2. Clear the DTC with the HDS.

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

Is DTC P0651 indicated?
YES - Go to step 4.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the PCM and the connectors of these parts:

- MAP sensor

- Output shaft (countershaft) speed sensor

- IMT actuator

- APP sensor

- FTP sensor



4. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

5. Disconnect the connectors of these parts:
- MAP sensor

- Output shaft (countershaft) speed sensor

- IMT actuator

- APP sensor

- FTP sensor

6. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

7. Clear the DTC with the HDS.

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

Is DTC P0651 indicated?
YES - Go to step 10.

NO - Go to step 9.


9. Check for Pending or Confirmed DTCs with the HDS while connecting each the connectors of these parts:
- MAP sensor

- Output shaft (countershaft) speed sensor

- IMT actuator

- APP sensor

- FTP sensor

Is DTC P0651 indicated?
YES - Replace the part that caused the DTC when it was reconnected, then go to step 14.

NO - Check for poor connections or loose terminals at the PCM and the connectors of these parts:

- MAP sensor

- Output shaft (countershaft) speed sensor

- IMT actuator

- APP sensor

- FTP sensor

If the connections and the terminals are OK, go to step 1 and recheck.


10. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

11. Jump the SCS line with the HDS.

12. Disconnect PCM connectors A (49P), B (49P), and C (49P).

13. Check for continuity between body ground and PCM connector terminals A25, B36, and C11 individually.

Is there continuity?
YES - Repair short in the wire between the PCM (A25, B36, or C11) and each sensor, then go to step 14.

NO - Go to step 20.






14. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

15. Reconnect all connectors.

16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

17. Reset the PCM with the HDS.

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

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

Is DTC P0651 indicated?
YES - Check for poor connections or loose terminals at the PCM and the connectors of these parts:

- MAP sensor

- Output shaft (countershaft) speed sensor

- IMT actuator

- APP sensor

- FTP sensor

If the connections and the terminals are OK, go to step 1 and recheck.

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


20. Reconnect all connectors.

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

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

Is DTC P0651 indicated?
YES - If the PCM was updated, substitute a known-good PCM, Initial Inspection and Diagnostic Overview then recheck. If the PCM was substituted, check for poor connections or loose terminals at the PCM and the connectors of these parts:

- MAP sensor

- Output shaft (countershaft) speed sensor

- IMT actuator

- APP sensor

- FTP sensor

If the connections and the terminals are OK, go to step 1.

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. PCM Replacement If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.