C1252

Circuit Description
DTC C1252 diagnoses an ABS motor that energizes longer than expected. The following conditions may cause the longer period of being energized:
^ A wheel speed sensor malfunctions.
^ The left front brake solenoid valve mechanically fails open.
^ The ABS brake motor wires are crossed.

Conditions for Setting the DTC
DTC C1252 can only set during an ABS stop.
A malfunction exists if the EBCM commands the left front ABS channel in release for greater than three seconds.

Action Taken When the DTC Sets
^ A malfunction DTC stores.
^ The ABS disables.
^ The ABS warning indicator turns ON.
^ A rehome is commanded to ensure the motors are in the home position.

Conditions for Clearing the DTC
^ The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
^ 100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.

Diagnostic Aids
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction. DTC C1252 may occur if the vehicle is on ice and the steering wheel is turned to lock during braking. Use the scan tool hydraulic test to ensure the total brake system is functional.
Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:
^ Backed out terminals
^ Improper mating
^ Broken locks
^ Improperly formed or damaged terminals
^ Poor terminal-to-wiring connections
^ Physical damage to the wiring harness
Clear the DTCs after completing the diagnosis. Test drive the vehicle for three drive cycles in order to verify that the DTC does not reset. Use the following procedure in order to complete one drive cycle:
1. Start the vehicle.
2. Drive the vehicle over 16 km/h (10 mph).
3. Stop the vehicle.
4. Turn the ignition switch to the OFF position.

Test Description
4. This test identifies a motor or hydraulic modulator malfunction.
5. This test checks for a solenoid that may have mechanically failed open.
6. This test checks for a solenoid that may have mechanically failed closed.
7. This test isolates the malfunction to either the solenoid or the hydraulic modulator.
9. This test checks for proper operation of the hydraulic modulator.








DTC C1252 LF ABS Channel in Release Too Long