( TF09EABK72100090720FAAT00 )
DTC Troubleshooting: P0720 (122)
DTC P0720:
 Output Shaft (Countershaft) Speed Sensor Circuit Malfunction (M/T model)
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
  1. Start the engine. Hold the engine speed at 3,000 rpm (min −1 ) without load (in neutral) until the radiator fan comes on, then let it idle.
  1. Test-drive for several minutes.
  1. Check the C SHAFT SPD in the DATA LIST with the HDS.
Is any vehicle speed indicated?
YES -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the ECM.■
NO -
Go to Step 4 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the output shaft (countershaft) speed sensor 3P connector.
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between output shaft (countershaft) speed sensor 3P connector terminal No. 1 and body ground.
Is there about 5 V?
YES -
Go to Step 8 .
NO -
Repair open in the wire between the ECM (C13) and the output shaft (countershaft) speed sensor, then go to Step 18 .
  1. Measure the voltage between output shaft (countershaft) speed sensor 3P connector terminal No. 2 and body ground.
Is there about 5 V?
YES -
Go to Step 9 .
NO -
Go to Step 10 .
  1. Measure the voltage between output shaft (countershaft) speed sensor 3P connector terminals No. 1 and No. 3.
Is there about 5 V?
YES -
Go to Step 16 .
NO -
Repair open in the wire between the ECM (C14) and the output shaft (countershaft) speed sensor, then go to Step 18 .
  1. Turn the ignition switch to LOCK (0).
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector B (49P).
  1. Check for continuity between ECM connector terminal B38 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM (B38) and the output shaft (countershaft) speed sensor, then go to Step 18 .
NO -
Go to Step 14 .
  1. Connect output shaft (countershaft) speed sensor 3P connector terminal No. 2 to body ground with a jumper wire.
  1. Check for continuity between ECM connector terminal B38 and body ground.
Is there continuity?
YES -
Go to Step 25 .
NO -
Repair open in the wire between the ECM (B38) and the output shaft (countershaft) speed sensor, then go to Step 18 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect all connectors.
  1. Turn the ignition switch to ON (II).
  1. Reset the ECM with the HDS.
  1. Test-drive under these conditions:
    • Engine coolant temperature (ECT SENSOR 1) above 80 °C (176 °F)
    • Transmission in 5th gear
    • ENGINE SPEED between 2,000−3,000 rpm (min −1 )
    • Drive for several minutes, then decelerate (with the throttle fully closed) for 8 seconds
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0720 indicated?
YES -
Check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the ECM, then go to Step 1 .
NO -
Go to Step 24 .
  1. Monitor the OBD STATUS for DTC P0720 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in Step 23 , go to the indicated DTC's troubleshooting.■
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the ECM, then go to Step 1 . If the screen indicates NOT COMPLETED, go to Step 22 .
  1. Reconnect all connectors.
  1. Test-drive under these conditions:
    • Engine coolant temperature (ECT SENSOR 1) above 80 °C (176 °F)
    • Transmission in 5th gear
    • ENGINE SPEED between 2,000−3,000 rpm (min −1 )
    • Drive for several minutes, then decelerate (with the throttle fully closed) for 8 seconds
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0720 indicated?
YES -
Check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 27 . If the ECM was substituted, go to Step 1 .
NO -
Go to Step 29 .
  1. Monitor the OBD STATUS for DTC P0720 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs were indicated in Step 28 , go to the indicated DTC's troubleshooting.■
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 27 . If the ECM was substituted, go to Step 1 . If the screen indicates NOT COMPLETED, go to Step 27 .