Automatic Transmission
DTC P0721: Problem in Output Shaft (Countershaft) Speed Sensor CircuitDTC 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, and review General Troubleshooting Information.
^ 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.
3. Raise the vehicle on a lift, make sure it is supported securely, and allow all four wheels to rotate freely.
4. Start the engine, disable the VSA by pressing the VSA OFF button, run the vehicle in D, and hold the vehicle at speeds over 12 mph (20 km/h) for at least 10 seconds when the transmission is not shifting. Slow down and stop the wheels.
5. Monitor the OBD STATUS for P0721 or P0722 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Intermittent failure, the system is OK at this time. Check for loose or poor connections at the PCM and the output shaft (countershaft) speed sensor connectors.M
NO - If the screen indicates FAILED, go to step 6. If the screen 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 connectors B (44P), C (44P).
9. Disconnect the output shaft (countershaft) speed sensor connector.
10. Check for continuity between PCM connector terminals B1, B36, B43, and C40 and body ground individually.
Is there continuity?
YES - Go to step 11.
NO - Repair an open in the wires between PCM connector terminals B1, B36, B43, C40, and ground (G101, G102), or repair poor ground (G101, G102), then go to step 36.
11. Connect PCM connectors B (44P) and C (44P).
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 19.
NO - Go to step 14.
14. Turn the ignition switch to LOCK (0).
15. Jump the SCS line with the HDS.
16. Disconnect PCM connector B (44P).
17. Check for continuity between PCM connector terminal B18 and output shaft (countershaft) speed sensor connector terminal No. 1.
Is there continuity?
YES - Go to step 18.
NO - Repair an open in the wire between PCM connector terminal B18 and the output shaft (countershaft) speed sensor, then go to step 36.
18. Check for continuity between PCM connector terminal B18 and body ground.
Is there continuity?
YES - Repair a short to ground in the wire between PCM connector terminal B18 and the output shaft (countershaft) speed sensor, then go to step 36.
NO - Go to step 43.
19. Turn the ignition switch to LOCK (0).
20. Jump the SCS line with the HDS.
21. Disconnect PCM connector B (44P).
22. Check for continuity between output shaft (countershaft) speed sensor connector terminal No. 2 and body ground.
Is there continuity?
YES - Repair a short to ground in the wire between PCM connector terminal B40 and the output shaft (countershaft) speed sensor connector, then go to step 36.
NO - Go to step 23.
23. Check for continuity between PCM connector terminal B33 and output shaft (countershaft) speed sensor connector terminal No. 3.
Is there continuity?
YES - Go to step 24.
NO - Repair an open in the wire between the output shaft (countershaft) speed sensor connector and PCM connector terminal B33, then go to step 36.
24. Connect PCM connector B (44P).
25. Turn the ignition switch to ON (II).
26. Measure the voltage between output shaft (countershaft) speed sensor connector terminals No. 2 and No. 3.
Is there about 5 V?
YES - Go to step 31.
NO - Go to step 27.
27. Turn the ignition switch to LOCK (0).
28. Jump the SCS line with the HDS.
29. Disconnect PCM connector B (44P).
30. Check for continuity between PCM connector terminal B40 and output shaft (countershaft) speed sensor connector terminal No. 2.
Is there continuity?
YES - Go to step 43.
NO - Repair an open in the wire between PCM connector terminal B40 and the output shaft (countershaft) speed sensor, then go to step 36.
31. Connect the output shaft (countershaft) speed sensor connector.
32. Clear the DTC with the HDS.
33. Start the engine, disable the VSA by pressing the VSA OFF button, run the vehicle in D, and hold the vehicle at speeds over 12 mph (20 km/h) for at least 10 seconds when the transmission is not shifting. Slow down and stop the wheels.
34. Monitor the OBD STATUS for P0721 or P0722 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Go to step 43.
NO - Go to step 35.
35. Replace the output shaft (countershaft) speed sensor.
36. Reconnect all connectors.
37. Turn the ignition switch to ON (II).
38. Clear the DTC with the HDS.
39. Raise the vehicle on a lift, make sure it is supported securely, and allow all four wheels to rotate freely.
40. Start the engine, disable the VSA by pressing the VSA OFF button, run the vehicle in D, and hold the vehicle at speeds over 12 mph (20 km/h) for at least 10 seconds when the transmission is not shifting, then slow down and stop the wheels.
41. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0721 or P0722 indicated?
YES - Check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the PCM, then go to step 1.
NO - Go to step 42.
42. Monitor the OBD STATUS for P0721 or P0722 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTC or DTCs were indicated on step 41, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 40.
43. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
44. Raise the vehicle on a lift, make sure it is supported securely, and allow all four wheels to rotate freely.
45. Start the engine, disable the VSA by pressing the VSA OFF button, run the vehicle in D, and hold the vehicle at speeds over 12 mph (20 km/h) for at least 10 seconds when the transmission is not shifting, then slow down and stop the wheels.
46. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0721 or P0722 indicated?
YES - Check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 45. If the PCM was substituted, go to step 1.
NO - Go to step 47.
47. Monitor the OBD STATUS for P0721 or P0722 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Temporary DTCs or DTCs were indicated on step 46, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 45. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 45.