C0251

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Part 2 Of 2:

CIRCUIT DESCRIPTION
The Electronic Brake Control Module (EBCM) microprocessor will ground the indicated solenoid coil (RF dump/isolation, LF dump/isolation, or Rear dump/isolation) circuit to energize the solenoid coil whenever the solenoid valve is needed. Refer to ABS Braking Mode in ABS System Operation. The magnetic force created by the solenoid coil will close the isolation valve.

CONDITIONS FOR SETTING THE DTC Open Circuit
^ The ABS bulb check is complete
^ Low voltage exists on the EBCM solenoid driver circuit when high voltage is expected (the solenoid is not energized).

Shorted Circuit
^ The ABS bulb check is complete
^ High voltage is present on the EBCM solenoid driver circuit when the voltage is expected to be low (solenoid energized).

ACTION TAKEN WHEN THE DTC SETS
^ The ABS indicator lamp turns on
^ The ABS disables

Diagnostic Trouble Codes (DTCs) C0241-C0258 are Ignition Latched DTCs, which indicates the above actions remain true until the ignition is turned to OFF (even if the cause of the DTC is intermittent).

CONDITIONS FOR CLEARING THE DTC
^ Repair the conditions responsible for setting the DTC
^ Use the Scan Tool Clear DTCs function

DIAGNOSTIC AIDS
This DTC usually sets because of an open/shorted solenoid coil within the EBCM. The solenoid coil is located within the BPMV and is not serviceable. If the test does not repair the DTC, then replace the EBCM.

If this DTC sets with other DTCs, check for the following conditions:
^ A poor EBCM power or signal ground
^ A poor EBCM power or ignition feed

TEST DESCRIPTION
The numbers below refer to the steps in the diagnostic table:
3. This step determines the resistance of the power ground circuit.
4. This step determines the battery voltage available to the EBCM.
7. This step determines the resistance of the signal ground circuit.
8. This step determines the ignition voltage available to the EBCM.