DTC Troubleshooting

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

DTC P0721: Problem in Output Shaft (Countershaft) Speed Sensor Circuit

DTC P0722: Problem in Output Shaft (Countershaft) Speed Sensor Circuit (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. Turn the ignition switch to ON (II).

2. Clear the DTC with the HDS.

3. 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 24.

4. 4WD: Raise the vehicle on a lift, make sure it is securely supported, and allow all four wheels to rotate freely.
2WD: Block the rear wheels and 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.

5. Start the engine, disable the VSA by pressing the VSA OFF switch, run the vehicle with the shift lever in D, with the engine speed 2,000 rpm or higher for at least 10 seconds. Slow down and stop the wheels.

6. Monitor the OBD STATUS for P0721 or P0722 in the DTCs MENU with the HDS.

Does the HDS indicate FAILED?
YES - Go to step 7.

NO - If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals between the output shaft (countershaft) speed sensor and the PCM. If the screen indicates NOT COMPLETED, go to step 5.


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

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

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

10. 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 11.

NO - Go to step 18.






11. 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 23.

NO - Go to step 12.






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

13. Jump the SCS line with the HDS.

14. Disconnect PCM connector A (31P).

15. Check for continuity between PCM connector terminal A8 and body ground, and between PCM connector terminal A9 and body ground.

Is there continuity?
YES - Go to step 16.

NO - Repair open in the wires between PCM connector terminals A8, A9, and ground (G101), or repair poor ground (G101), then go to step 23.






16. Check for continuity between PCM connector terminal A9 and output shaft (countershaft) speed sensor connector terminal No. 3.

Is there continuity?
YES - Go to step 17.

NO - Repair open in the wire between PCM connector terminal A9 and the output shaft (countershaft) speed sensor, then go to step 23.






17. Check for continuity between PCM connector terminal A18 and output shaft (countershaft) speed sensor connector terminal No. 2.

Is there continuity?
YES - Go to step 18.

NO - Repair open in the wire between PCM connector terminal A18 and the output shaft (countershaft) speed sensor, then go to step 22.






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

Is there continuity?
YES - Repair short to body ground in the wire between PCM connector terminal A21 and the output shaft (countershaft) speed sensor, then go to step 23.

NO - Go to step 29.






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

20. Jump the SCS line with the HDS.

21. Disconnect PCM connector A (31P).

22. Check for continuity between PCM connector terminal A21 and output shaft (countershaft) speed sensor connector terminal No. 1.

Is there continuity?
YES - Go to step 29.

NO - Repair open in the wire between PCM connector terminal A21 and the output shaft (countershaft) speed sensor, then go to step 23.






23. Reconnect all connectors.

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

25. Clear the DTC with the HDS.

26. Start the engine, disable the VSA by pressing the VSA OFF switch, run the vehicle with the shift lever in D, with the engine speed 2,000 rpm or higher for at least 10 seconds. Slow down and stop the wheels.

27. Check for Temporary DTCs or DTCs with the HDS.

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

NO - Go to step 28.


28. Monitor the OBD STATUS for P0721 or P0722 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 27, go to the indicated DTC's troubleshooting.

NO - If the HDS indicates FAILED, check for poor connections or loose terminals between the output shaft (countershaft) speed sensor and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 26.


29. Reconnect all connectors.

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

31. Start the engine, disable the VSA by pressing the VSA OFF switch, run the vehicle with the shift lever in D, with the engine speed 2,000 rpm or higher for at least 10 seconds. Slow down and stop the wheels.

32. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0721 or P0722 indicated?
YES - Check for poor connections or loose terminals between 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 go to step 31. If the PCM was substituted, go to step 1.

NO - Go to step 33.


33. Monitor the OBD STATUS for P0721 or P0722 in the DTCs MENU with the HDS.

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 Temporary DTCs or DTCs were indicated in step 32, go to the indicated DTC's troubleshooting.

NO - If the HDS indicates FAILED, check for poor connections or loose terminals between 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 go to step 31. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 31.