DTC 54: Rear Channel In Release Too Long: Description

DTC 54 can be set on during an ABS stop. A malfunction exists if EBCM commands left front channel in release for 3 seconds.

1. Test drive vehicle. Using scan tool, select DATA LIST. While decelerating from 35 MPH to zero, monitor all wheel speeds. If any wheel speed is erratic or intermittent, go DTC 21-24 (as applicable). If wheel speeds appear acceptable, go to next step.
2. Turn ignition switch to LOCK position. Raise and support rear of vehicle. Ensure both rear wheels can be spun freely by hand. If either does not spin freely, inspect and repair cause of resistance. If rear brake system is okay, go to next step.
3. Turn ignition on. Using scan tool, select manual control function. Select rear motor apply. Apply firm pressure to brake pedal. Command apply of rear motor. Attempt to spin rear wheels by hand. If rear wheels can be rotated, maintain pressure on brake pedal and go to next step. If rear wheels can not be rotated, system is currently functioning correctly. See DIAGNOSTIC AIDS .
4. Using scan tool, command release of rear motor. Attempt to rotate rear wheels. If rear wheels can be rotated, go to next step. If rear wheels can not be rotated, rear motor circuit wires may be crossed. Inspect and repair wires as needed.
5. Using scan tool, perform gear tension relief function. Turn ignition switch to LOCK position. Remove ABS actuator assembly. See REMOVAL & INSTALLATION . Separate motor pack from hydraulic modulator. Connect motor pack wiring. Turn ignition switch to ON position. Using scan tool, perform motor test. If all 3 motor back gears (small gears) spin freely, replace hydraulic modulator. If all 3 motor back gears (small gears) do not spin freely, replace motor pack.