DTC Troubleshooting

DTC Troubleshooting: P0451

DTC P0451:

FTP Sensor Circuit Range/Performance Problem

NOTE:

- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information Initial Inspection and Diagnostic Overview.
- If DTC P2422 is stored at the same time as DTC P0451, troubleshoot DTC P2422 first, then recheck for DTC P0451.

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

2. Clear the DTC with the HDS.

3. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

4. Test drive under these conditions:

- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
- Transmission in D
- Vehicle speed at 35 mph (60 km/h) for 10 seconds, then decelerate (with the throttle fully closed). Repeat this three or more times

5. Monitor the OBD STATUS for DTC P0451 in the DTCs MENU with the HDS.

Does the HDS indicate FAILED?

YES -

Go to step 6.

NO -

If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the FTP sensor and the PCM. If the HDS indicates NOT COMPLETED, go to step 3 and recheck.

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

7. Replace the FTP sensor Service and Repair.

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

9. Reset the PCM with the HDS.

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

11. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

12. Test drive under these conditions:

- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
- Transmission in D
- Vehicle speed at 35 mph (60 km/h) for 10 seconds, then decelerate (with the throttle fully closed). Repeat this three or more times

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

Is DTC P0451 indicated?

YES -

Check for a restriction in the FTP vent, and poor connections or loose terminals at the FTP sensor and the PCM, then go to step 1.

NO -

Go to step 14.

14. Monitor the OBD STATUS for DTC P0451 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED?

YES -

Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 13, go to the indicated DTC's troubleshooting.�

NO -

If the HDS indicates FAILED, check for poor connections or loose terminals at the FTP sensor and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 11 and recheck.