A048

Diagnostic Chart:

Wiring Diagram:

Circuit Description:
This DTC is designed to detect a stripped nut or gear assembly during initialization. During the homing sequence, the piston should reach the top of the bore resulting in a stalled motor. If this does not occur, the motor must be spinning with little or no resistance, indicating a nut/screw or gear malfunction.

Failure Condition:
DTC A048 can only be set during initialization. If the feedback current is less than the command current for a specified period of time, a malfunction exists.

Action Taken:
A malfunction DTC is stored, ABS is disabled, and the "ABS INOP" lamp is turned "ON."

Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step checks to see if the corresponding open motor DTC is also set.
2. This step verifies that the motor was actually applied as command by observing feedback current.
3. This step verifies that the motor can release.
4. This step verifies that the motor can be applied by observing pedal movement.
5. This step checks for a stripped gear on the motor pack (unit with three small gears).
6. This step checks for a stripped gear on the hydraulic modulator (unit with three large gears).
7. This step determines whether the hydraulic modulator or the motor pack has an internal malfunction.
8. This step checks for a malfunctioning EBCM.
9. This step verifies that the motor can be applied under a load situation.
10. This step checks for high resistance in the motor "HIGH" circuitry.
11. This step checks for high resistance in the motor "LOW" circuitry.
12. This step checks for proper resistance of the motor windings.
13. This step verifies that the hydraulic modulator in functioning properly.

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 "Tech 1 Diagnostics." If the DTC only fails once and DTC A061 also fails, refer to DTC A061. A061 If intermittent and enhanced diagnostics shows this DTC fails during ABS, refer to DTC A061.

Depending on the frequency of the malfunction, a physical inspection of the mechanical parts suspected may be necessary.