P0931-BTSI CONTROL CIRCUIT HIGH - ESM





For a complete wiring diagram Refer to Section 8W


  • When Monitored:

    Continuously with the ignition key on.

  • Set Condition:

    The DTC will set if the high side driver detects an open load for 10 seconds.


Possible Causes
  
ENGINE BRAKE DTC'S PRESENT
  
ABS DTC'S PRESENT
  
(B29) BRAKE SWITCH SIGNAL OPEN
  
(B29) BRAKE SWITCH SIGNAL SHORT TO VOLTAGE
  
SHIFTER LEVER ASSEMBLY
  

Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

Theory of Operation


The brake switch signal must be active before the shift lever can be moved out of the park position. The Shifter Lever Assembly (SLA) Electronic Shift Module (ESM) receives two brake switch signals. The first signal is a CAN C Bus message sent to the shifter lever assembly. The second signal is a hard wired brake switch signal to the shifter lever assembly. The CAN C Bus message is the primary brake switch signal and the hard wired signal serves as the backup brake switch signal. These two brake switch signals are compared against each other to verify proper brake switch operation.



Diagnostic Test

1.ENGINE DTCs PRESENT



Are there any Engine brake DTCs present?

Yes


No
  • Go To 2

2.ABS MODULE DTCs PRESENT



Are there any ABS DTCs present?

Yes


No
  • Go To 3

3.(B29) BRAKE SWITCH SIGNAL OPEN






NOTE: Check connectors - Clean/repair as necessary.




Is the resistance above 5.0 ohms?

Yes


No
  • Go To 4

4.(B29) BRAKE SWITCH SIGNAL SHORT TO VOLTAGE





NOTE: Check connectors - Clean/repair as necessary.





Is the voltage above 0.5 volts?

Yes


No