DTC Troubleshooting
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. Raise the vehicle on a lift, make sure it is securely supported, and allow all four wheels to rotate freely.
3. Check for proper output shaft (countershaft) speed sensor installation. If the sensor is installed improperly correct problem, then go to step 36.
4. Start the engine, run the vehicle in the D position with engine speed 2,000 rpm or higher for more than 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 result 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 the output shaft (countershaft) speed sensor connectors. If the HDS indicates NOT COMPLETED, return to step 4 and recheck.
6. Turn the ignition switch OFF.
7. Jump the SCS line with the HDS.
8. Disconnect PCM connector C (44P).
9. Check for continuity between PCM connector terminals C40 and body ground, and between C44 and body ground.
Is there continuity?
YES - Go to step 10.
NO - Repair open in the wires between PCM connector terminals C40, C44 and ground (G101), or repair poor ground (G101), then go to step 36.
10. Connect PCM connector B (44P).
11. Disconnect the output shaft (countershaft) speed sensor connector.
12. Turn the ignition switch 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 18.
NO - Go to step 14.
14. Turn the ignition switch OFF.
15. Disconnect PCM connector B (44P).
16. 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 17.
NO - Repair open in the wire between PCM connector terminal B18 and the output shaft (countershaft) speed sensor, then go to step 36.
17. Check for continuity between PCM connector terminal B18 and body ground.
Is there continuity?
YES - Repair short in the wire between PCM connector terminal B18 and the output shaft (countershaft) speed sensor, then go to step 36.
NO - Check for poor connections and loose terminals at the PCM. If the connections are OK, go to step 32.
18. Turn the ignition switch OFF.
19. Disconnect PCM connector C (44P).
20. 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 C43 and the output shaft (countershaft) speed sensor connector, then go to step 36.
NO - Go to step 21.
21. 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 22.
NO - Repair open in the wire between the output shaft (countershaft) speed sensor connector and PCM connector terminal B33, then go to step 36.
22. Connect PCM connector B (44P).
23. Turn the ignition switch ON (II).
24. 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 28.
NO - Go to step 25.
25. Turn the ignition switch OFF.
26. Disconnect PCM connector C (44P).
27. Check for continuity between PCM connector terminal C43 and output shaft (countershaft) speed sensor connector terminal No. 2.
Is there continuity?
YES - Go to step 32.
NO - Repair open in the wire between PCM connector terminal C43 and the output shaft (countershaft) speed sensor, then go to step 36.
28. Connect the output shaft (countershaft) speed sensor connector.
29. Clear the DTC with the HDS.
30. Start the engine, run the vehicle in the D position with engine speed 2,000 rpm or higher for more than 10 seconds. Slow down and stop the wheels.
31. Monitor the OBD status for P0721 or P0722 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate FAILED?
YES - Replace the output shaft (countershaft) speed sensor, then go to step 36.
NO - Go to step 32.
32. Update the A/T software in the PCM if it does not have the latest software, or substitute a known-good PCM.
33. Start the engine, run the vehicle in the D position with engine speed 2,000 rpm or higher for more than 10 seconds. Slow down and stop the wheels.
34. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS.
Is DTC P0721 or P0722 indicated?
YES - If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, 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 result indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other DTCs were indicated on step 34, go to the indicated DTC's troubleshooting.
NO - If the HDS indicates FAILED, 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, then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 33 and recheck.
36. Clear the DTC with the HDS.
37. Start the engine, run the vehicle in the D position with engine speed 2,000 rpm or higher for more than 10 seconds. Slow down and stop the wheels.
38. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu 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 39.
39. Monitor the OBD status for P0721 or P0722 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate PASSED?
YES - Troubleshooting is complete. If any other DTCs were indicated on step 38, go to the indicated DTC's troubleshooting.
NO - If the HDS indicates FAILED, 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, return to step 37 and recheck.