P0720

DTC P0720: Problem in Countershaft Sensor Circuit

NOTE: Record all freeze data before you troubleshoot.

1. Check the countershaft speed sensor installation.
Is the countershaft speed sensor installed properly ?
YES-Go to step 2.
NO-Reinstall and rechecks
2. Disconnect the 2P connector from the countershaft speed sensor.





3. Measure countershaft speed sensor resistance at the sensor connector.
Is the resistance 400 - 600 ohms ?
YES-Go to step 4.
NO-Replace the countershaft speed sensor.
4. Disconnect the D (16P) connector from the PCM.





5. Check for continuity between body ground and PCM connector terminals D10 and D16 individually.
Is there continuity?
YES-Repair short to ground in the wires between PCM connector terminals D10 and D16 and the countershaft speed sensor.
NO-Go to step 6.
6. Connect the countershaft speed sensor connector.





7. Measure the resistance between PCM connector terminals D10 and D16.
Is the resistance 400 - 600 ohms ?
YES-Check for loose terminal fit in the PCM connectors. If necessary, substitute a known-good PCM and recheck.
NO-Repair loose terminal or open in the wires between PCM connector terminals D10 and D16 and the countershaft speed sensor.