FixVault

Possible Causes

Possible Causes 
ENGINE BRAKE DTCS PRESENT
WIN DTCS PRESENT
(K321) BTSI CONTROL CIRCUIT SHORTED TO GROUND
(K321) BTSI CONTROL CIRCUIT OPEN
SHIFTER LEVER ASSEMBLY

Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding.  Refer to DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure .