DTC Troubleshooting: P0720 (9-1)

DTC P0720:  Problem in Countershaft Speed Sensor Circuit

NOTE: Record all freeze data before you troubleshoot.

1.Check the fuel and emissions system problem is indicated by the DTC.

Is there any fuel and emissions DTC?


YES - Perform the troubleshooting flowchart for the indicated code(s). Recheck for code P0720 after troubleshooting.n


NO - Go to 2.


2.Turn the ignition switch OFF.

3.Disconnect the battery negative terminal.

4.Disconnect PCM connector A (31P).

5.Check for continuity between PCM connector terminals A23 and body ground, and between A24 and body ground.

 

Is there continuity?


YES - Go to 6.


NO - Repair open in the wires between PCM connector terminals A23 and ground ( G101), between A24 and ground (G101), and repair poor ground (G101).n


6.Connect PCM connector A (31P).

7.Connect the battery negative terminal.

8.Disconnect the countershaft speed sensor connector.

9.Turn the ignition switch ON (II).

10.Measure the voltage between the No. 1 terminal of the countershaft speed sensor connector and body ground.

 

Is there about 5 V?


YES - Go to 11.


NO - Go to 21.


11.Turn the ignition switch OFF.

12.Check for continuity between the No. 2 terminal of the countershaft speed sensor connector and body ground.

 

Is there continuity?


YES - Repair short to ground in the wire between PCM connector terminal C15 and the countershaft speed sensor connector.n


NO - Go to 13.

13.Check for continuity between the No. 3 terminal of the countershaft speed sensor connector and body ground.

 

Is there continuity?


YES - Go to 14.


NO - Repair open in the wire between the countershaft speed sensor connector and ground ( G101).n


14.Turn the ignition switch ON (II).

15.Measure the voltage between the No. 2 and No. 3 terminals of the countershaft speed sensor connector.

 

Is there about 5 V?


YES - Go to 16.


NO - Go to 26.

16.Connect the countershaft speed sensor connector.

17.Measure the voltage between PCM connector terminals C15 and A23 or A24.

 

Is the voltage 0 V or about 5 V?


YES - Go to 18.


NO - Replace the countershaft speed sensor.n

18.For 4WD model: Raise the vehicle, make sure it is securely supported, and allow the all four wheels to rotate freely.
For 2WD model: Raise the front of the vehicle, make sure it is securely supported, and allow the front wheels to rotate freely.

19.Start the engine, then shift to [D] position and drive the vehicle.

20.Measure the voltage between PCM connector terminals C15 and A23 or A24.

 

Is there 1.5 V-3.5 V?


YES - Check for loose terminal fit in the PCM connectors. If necessary, substitute a known-good  PCM and recheck.n


NO - Replace the countershaft speed sensor.n

21.Measure the voltage between PCM connector terminals A21 and A23 or A24.

 

Is there 4.75 V-5.25 V?


YES - Repair open in the wire between PCM connector terminal A21 and the countershaft speed sensor connector.n


NO - Go to 22.

22.Turn the ignition switch OFF.

23.Disconnect the battery negative terminal.

24.Disconnect PCM connector A (31P).

25.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 countershaft speed sensor connector.n


NO - Check for loose terminal fit in the PCM connectors. If necessary, substitute a known-good  PCM and recheck.n

26.Measure the voltage between PCM connector terminals C15 and A23 or A24.

 

Is there about 5 V?


YES - Repair open in the wire between PCM connector terminal C15 and the countershaft speed sensor connector.n


NO - Check for loose terminal fit in the PCM connectors. If necessary, substitute a known-good  PCM and recheck.n