DTC Troubleshooting: P0721 (9-5)
| DTC P0721: | Problem in Output Shaft (Countershaft) Speed Sensor Circuit |
KE, KG, and KS Models
NOTE:
- Record all freeze data and review General Troubleshooting Information before you troubleshoot.
- This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.
| 1. | Record all freeze data, then clear the DTC with the HDS. |
| 2. | Raise the vehicle, make sure it is securely supported, and allow the all four wheels to rotate freely. |
| 3. | Start the engine, drive the vehicle in the D position, and hold the vehicle at speeds over 48 km/h (30 mph) for more than 10 seconds, then slow down and stop the wheels. |
| 4. | Check the OBD status in DTC Monitor Tool from DTCs/Freeze Data in A/T Mode Menu for a pass/fail test of code P0721. Did the result indicate a fail? YES - Go to 5. NO - Intermittent failure, the system is OK at this time. If the tester indicates NOT COMPLETE, return to 3 and recheck.n |
| 5. | Turn the ignition switch OFF. |
| 6. | Jump the SCS line with the HDS. |
| 7. | Disconnect PCM connector A (31P) and output shaft (countershaft) speed sensor connector. |
| 8. | Check for continuity between PCM connector terminals A8 and body ground, and between A9 and body ground.
Is there continuity? YES - Go to 9. NO - Repair open in the wire between PCM connector terminals A8, A9, and ground (G101), or repair poor ground (G101), then go to 29. |
| 9. | Connect PCM connector A (31P). |
| 10. | Turn the ignition switch ON (II). |
| 11. | Measure the voltage between output shaft (countershaft) speed sensor connector terminal No. 1 and body ground.
Is there about 5 V? YES - Go to 12. NO - Go to 23. |
| 12. | Turn the ignition switch OFF. |
| 13. | Disconnect PCM connector A (31P). |
| 14. | Check for continuity between output shaft (countershaft) speed sensor connector terminal No. 2 and body ground.
Is there continuity? YES - Repair short to ground in the wire between PCM connector terminal A18 and output shaft (countershaft) speed sensor, then go to 29. NO - Go to 15. |
| 15. | Check for continuity between output shaft (countershaft) speed sensor connector terminal No. 3 and PCM connector terminal A24.
Is there continuity? YES - Go to 16. NO - Repair open in the wire between output shaft (countershaft) speed sensor and PCM connector terminal A24, then go to 29. |
| 16. | Connect PCM connector A (31P). |
| 17. | Turn the ignition switch ON (II). |
| 18. | Measure the voltage between output shaft (countershaft) speed sensor connector terminals No. 2 and No. 3.
Is there about 5 V? YES - Go to 19. NO - Go to 28. |
| 19. | Connect output shaft (countershaft) speed sensor connector. |
| 20. | Measure the voltage between PCM connector terminals A18 and A8 or A9.
Is there 0 V or about 5 V? YES - Go to 21. NO - Replace the output shaft (countershaft) speed sensor, then go to 29. |
| 21. | Shift to the P position. Start the engine, and let it at idle. |
| 22. | Shift to the D position, and measure the voltage between PCM connector terminals A18 and A8 or A9.
Is there 1.5-3.5 V? YES - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.n NO - Replace the output shaft (countershaft) speed sensor, then go to 29. |
| 23. | Measure the voltage between PCM connector terminals A21 and A8 or A9.
Is there about 5 V? YES - Repair open in the wire between PCM connector terminal A21 and the output shaft (countershaft) speed sensor, then go to 29. NO - Go to 24. |
| 24. | Turn the ignition switch OFF. |
| 25. | Jump the SCS line with the HDS. |
| 26. | Disconnect PCM connector A (31P). |
| 27. | Check for continuity between PCM connector terminal A21 and body ground.
Is there continuity? YES - Repair short to ground in the wire between PCM connector terminal A21 and the output shaft (countershaft) speed sensor connector, then go to 29. NO - Check for loose or poor connections at PCM connector terminal A21. If the connection is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.n |
| 28. | Measure the voltage between PCM connector terminals A18 and A8 or A9.
Is there about 5 V? YES - Repair open in the wire between PCM connector terminal A18 and the output shaft (countershaft) speed sensor connector, then go to 29. NO - Check for loose or poor connections at PCM connector terminal A18. If the connection is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.n |
| 29. | Clear the DTC with the HDS. |
| 30. | Test-drive the vehicle for several minutes under the same conditions as those indicated by the freeze data. |
| 31. | Check the OBD status in DTC Monitor Tool from DTCs/Freeze Data in A/T Mode Menu for a pass/fail test of code P0721. Did the result indicate a pass? YES - The problem has been corrected.n NO - Return to step 1 and recheck.n |