Code A046, Rear Axle Channel Will Not Move: Notes

This code is designed to detect a bound-up Expansion Spring Brake (ESB), a stuck motor or seized hydraulic modulator. When release is commanded during initialization, ESB should release motor, resulting in sensed current being less than commanded current (motor is spinning freely). If motor is not moving, sensed current will be equal to stall current.

1. Checks ability of motor to move, applying hydraulic pressure to wheel cylinders. A frozen piston or gear would result in no apply of rear brakes and a wheel that freely spins.
2. Checks if motor can also move to release piston. If motor were not able to release hydraulic pressure, wheel would not spin.
3. Releases motor pack tension before removal.
4. Isolates fault to either the motor pack or ABS hydraulic modulator.