DTC Troubleshooting: P0721
DTC P0721: Output Shaft (Countershaft) Speed Sensor Out of Range
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
P0721 Output Shaft (Countershaft) Speed Sensor Out of Range
   

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
Vehicle Speed
More than 315
km/h
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
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 PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
2.
Output shaft (countershaft) speed sensor circuit connectors and terminals condition check:

Output shaft (countershaft) speed sensor circuit connectors and terminals condition check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check for poor connections or loose terminals at these locations:
Output shaft (countershaft) speed sensor
PCM
Engine ground
Body ground

Are the connections and terminals OK?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Repair the connections or terminals.?
3.
Shorted wire check (NC line to power):

Shorted wire check (NC line to power)
?1.
Jump the SCS line with the HDS, and wait more than 1 minute.


?2.
Disconnect the following connectors.
Output shaft (countershaft) speed sensor 3P connector
PCM connector No. 1 (96P)

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Output shaft (countershaft) speed sensor 3P connector: disconnected
 
PCM connector No. 1 (96P): disconnected
Test point 1
Output shaft (countershaft) speed sensor 3P connector (female terminals) No. 2:
Test point 2
Body ground


Is there any voltage?

     
YES
     
     
     
Repair a short to power in the NC wire between PCM connector No. 1 terminal No. 38 and the output shaft (countershaft) speed sensor.?
     
NO