Antilock Braking System (ABS)

Fig. 361 Code 45: Right Front ABS Channel Will Not Move (Part 1 Of 2):

Fig. 361 Code 45: Right Front ABS Channel Will Not Move (Part 2 Of 2):

Right Front ABS Channel Will Not Move:

Circuit Description:
Current is supplied to the EMB through terminal "B" of the three-way motor pack connector. When a release of the EMB is commanded, the EBCM grounds the EMB input and allows the EMB to be energized to release the motor.

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

DTC Will Set When:
DTC 45 can be set during initialization. The EBCM commands the right front motor in the reverse and forward direction to ensure the motor moves properly. If the EBCM detects a condition in which it cannot move the motor in either direction, a malfunction exists.

Action Taken:
This malfunction indicates the channel can not be moved properly. A malfunction DTC is stored, ABS is disabled and the "ABS" waining lamp is turned "ON."

DTC Chart Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Ensures motor circuits are in the proper connector cavity.
2. Checks for motor movement during release.
3. Compares feedback current to command current during apply.
4. Checks for a short between motor high and low circuits.
5. Checks for a shorted motor.
6. Ensures malfunction was not due to physical damage of the circuitry.
7. Checks if motor can apply properly under load.
8. Checks for a short to BATTERY in the right front EMB control circuit.
9. Checks for high resistance in the right front EMB control circuit.
10. Checks for high resistance in the EMB power feed circuit.
11. Checks for high resistance in the right front EMB.
12. Checks for proper operation of the hydraulic modulator.
13. Ensures malfunction was not due to poor terminal contact.
14. Isolates malfunction to either the right front EMB circuitry or the EBCM.
15. Ensures malfunction was not due to physical damage of the EMB circuitry.

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 as described in "Enhanced Diagnostics."

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.

NOTICE:
This DTC may fail if low voltage (10 volts or less) was present when initialization occurred. Ensure battery/charging system is functioning properly.