DTC A044: Left Front Channel Will Not Move

LEFT FRONT CHANNEL WILL NOT MOVE





Circuit Description
This DTC is designed to 6etect a bound-up ESB, a stuck motor, or a seized hydraulic modulator. When the release is commanded during initialization, the ESB should release the motor, resulting in the sensed current being less than the commanded current (motor is spinning freely). If the motor is not moving, the sensed current will be equal to the stall current.

Diagnosis
The system commands the motors in the reverse and the forward directions. The left front channel fails to move if the motor sense current is always greater than 7 amps.

Cause(s)
- The gears are frozen.
- A nut failed.
- The shaft is binding.
- There has been an ESB mechanical failure (the ESB does not release the motor).
- The motor pack assembly is malfunctioning.
- The piston is sticking or at the bottom of the bore.

Fail Action
This is a critical operational fault. The ABS is disabled and the ABS warning lamp is turned on.

Test Description
The number(s) below refer to step(s) on the diagnostic table.
2. This step checks for proper motor movement during apply and release commands from the scan tool.
3. This step verifies that the motor can actually apply when commanded.
4. This step compares the electronic brake control module (EBCM) command current to the motor feedback current.
5. This test determines if the malfunction is caused by a defective EBCM or by a short circuit.
6. This step checks for proper hydraulic modulator gear and piston movement.

Diagnostic Aids
An intermittent malfunction may be caused by a poor connection, wire insulation that has been rubbed through, or a wire that is broken inside the insulation.
Any circuitry that is suspected of causing the intermittent complaint should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wiring connections, or physical damage to the wiring harness.
Check the frequency of the malfunction by using the enhanced diagnostic feature of the scan tool as described in "Scan Tool Diagnostics". Scan Tool Diagnostics DTC: A044 may set after modulator disassembly if the modulator pistons are positioned at the bottom of their bore.








DTC A044 - Left Front Channel Will Not Move