Antilock Braking System (ABS)

DTC 45 Right Front ABS Channel Will Not Move:

Right Front ESB Wiring Schematic:

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

DTC WILL SET WHEN
DTC 45 can be set during normal operation. If the EBCM detects a condition in which it cannot move the ABS motor in either direction, a malfunction exists.

ACTION TAKEN
This malfunction indicates the channel cannot be moved properly. A malfunction DTC is stored, ABS is disabled and the ABS warning lamp is turned "ON."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Ensures that proper ABS motor circuits are located in the proper connector cavities.
2. Checks for proper ABS motor movement during apply and release commands from the Tech 1.
3. Compares EBCM command current to ABS motor feedback current.
4. Checks for a short circuit between the ABS motor "HIGH" and motor "LOW" circuits.
5. Checks for an ABS motor that is internally shorted.
6. Determines if the malfunction is due to poor terminal contact or the EBCM.
7. Verifies that the ABS motor can actually apply when commanded.
8. Checks for proper hydraulic modulator gear and piston movement.

DIAGNOSTIC AIDS
An "Intermittent" malfunction in this DTC may result from a mechanical part of the system that sticks, binds, or slips.

The frequency of the malfunction can be checked by using the enhanced diagnostic function of the Tech 1.

DTC 45 may set after modulator disassembly if the modulator pistons are positioned at the bottom of their bore.

Any circuitry, that is suspected as 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.