DTC Troubleshooting: P0721 (9-5)

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

KE, KG, and KS Models


NOTE:

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