DTC Troubleshooting

DTC Troubleshooting: P0721 (9), P0722 (9)

DTC P0721: Output Shaft (Countershaft) Speed Sensor (Range/Performance)

DTC P0722: Output Shaft (Countershaft) Speed Sensor (No Signal Input)

NOTE:

- Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information. How to Troubleshoot A/T Systems

- This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

1. Clear the DTC with the HDS.

2. Check for proper output shaft (countershaft) speed sensor installation. A/T Output Shaft (Countershaft) Speed Sensor Replacement (A/T) If the sensor is installed improperly, correct the problem, then go to step 32.

3. Raise the front of the vehicle, make sure it is securely supported, and allow the front wheels to rotate freely, or raise the vehicle on a lift.

4. Start the engine. Disable the VSA by pressing the VSA OFF switch for VSA-equipped model. Run the vehicle in D with the engine speed at 2,000 rpm or higher, for at least 10 seconds. Slow down and stop the wheels.

5. Monitor the OBD status for P0721 or P0722 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the HDS indicate FAILED?
YES - Go to step 6.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at the PCM and output shaft (countershaft) speed sensor connectors. If the HDS indicates NOT COMPLETED, return to step 4 and recheck.


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

7. Jump the SCS line with the HDS.

8. Disconnect PCM connector C (49P).

9. Check for continuity between PCM connector terminal C44 and body ground, and between terminal C48 and body ground.

Is there continuity?
YES - Go to step 10.

NO - Repair open in the wires between PCM connector terminals C44, C48 and ground (G101), or repair poor ground (G101), then go to step 31.






10. Connect PCM connector C (49P).

11. Disconnect the output shaft (countershaft) speed sensor connector.

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

13. Measure the voltage between output shaft (countershaft) speed sensor connector terminal No. 1 and body ground.

Is there about 5 V?
YES - Go to step 14.

NO - Go to step 22.






14. Measure the voltage between output shaft (countershaft) speed sensor connector terminals No. 2 and No. 3.

Is there about 5 V?
YES - Replace the output shaft (countershaft) speed sensor, A/T Output Shaft (Countershaft) Speed Sensor Replacement (A/T) then go to step 31.

NO - Go to step 15.






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

16. Jump the SCS line with the HDS.

17. Disconnect PCM connector B (49P).

18. Check for continuity between output shaft (countershaft) speed sensor connector terminal No. 2 and body ground.

Is there continuity?
YES - Repair short in the wire between PCM connector terminal B38 and output shaft (countershaft) speed sensor connector, then go to step 31.

NO - Go to step 19.






19. Disconnect PCM connector C (49P).

20. Check for continuity between PCM connector terminal C14 and output shaft (countershaft) speed sensor connector terminal No. 3.

Is there continuity?
YES - Go to step 21.

NO - Repair open in the wire between PCM connector terminal C14 and output shaft (countershaft) speed sensor, then go to step 31.






21. Check for continuity between PCM connector terminal B38 and output shaft (countershaft) speed sensor connector terminal No. 2.

Is there continuity?
YES - Go to step 26.

NO - Repair open in the wire between PCM connector terminal B38 and output shaft (countershaft) speed sensor, then go to step 31.






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

23. Jump the SCS line with the HDS.

24. Disconnect PCM connector C (49P).

25. Check for continuity between PCM connector terminal C13 and output shaft (countershaft) speed sensor connector terminal No. 1.

Is there continuity?
YES - Go to step 26.

NO - Repair open in the wire between PCM connector terminal C13 and the output shaft (countershaft) speed sensor, then go to step 31.






26. Reconnect all connectors.

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

28. Start the engine. Disable the VSA by pressing the VSA OFF switch for VSA-equipped model. Run the vehicle in D with the engine speed at 2,000 rpm or higher, for at least 10 seconds. Slow down and stop the wheels.

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

Is DTC P0721 or P0722 indicated?
YES - If the PCM was updated, substitute a known-good PCM, Initial Inspection and Diagnostic Overview then recheck. If the PCM was substituted, go to step 1.

NO - Go to step 30.


30. Monitor the OBD status for P0721 or P0722 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the HDS indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. Service and Repair If any other DTCs were indicated on step 29, go to the indicated DTC's troubleshooting.

NO - Check for poor connections and loose terminals at the output shaft (countershaft) speed sensor and the PCM. If the PCM was updated, substitute a known-good PCM, Initial Inspection and Diagnostic Overview then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 28 and recheck.


31. Reconnect all connectors.

32. Clear the DTC with the HDS.

33. Start the engine. Disable the VSA by pressing the VSA OFF switch for VSA-equipped model. Run the vehicle in D with the engine speed at 2,000 rpm or higher, for at least 10 seconds. Slow down and stop the wheels.

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

Is DTC P0721 or P0722 indicated?
YES - Check for poor connections and loose terminals at the output shaft (countershaft) speed sensor and the PCM, then go to step 1.

NO - Go to step 35.


35. Monitor the OBD status for P0721 or P0722 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the HDS indicate PASSED?
YES - Troubleshooting is complete. If any other DTCs were indicated on step 34, go to the indicated DTC's troubleshooting.

NO - Check for poor connections and loose terminals at the output shaft (countershaft) speed sensor and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 33 and recheck.