Antilock Braking System (ABS)

Fig. 360 Code 44: Left Front ABS Channel Will Not Move (Part 1 Of 2):

Fig. 360 Code 44: Left Front ABS Channel Will Not Move (Part 2 Of 2):

Left 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.

DTC Will Set When:
DTC 44 can be set at initialization. The EBCM commands the left 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" warning 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 left front EMB control circuit.
9. Checks for high resistance in the left front EMB control circuit.
10. Checks for high resistance in the EMB power feed circuit.
11. checks for high resistance in the left 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 left front EMB circuitry or the EBCM.
15. Ensures malfunction was not due to physical damage of the EMB circuit.

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 44 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.