C0068

DTC C0068 Pump Motor Locked Or Pump Motor Circuit Shorted (Part 1 Of 2):

DTC C0068 Pump Motor Locked Or Pump Motor Circuit Shorted (Part 2 Of 2):

Pump Motor Circuit Schematic:

CIRCUIT DESCRIPTION
The pump motor circuit is integral to the Electronic Brake Control Module (EBCM). The EBCM microprocessor energizes the relay within the EBCM to supply battery voltage to the high side of the pump motor. When pump motor activation is required, the EBCM microprocessor grounds the low side of the pump motor.

CONDITIONS FOR SETTING THE DTC
^ Vehicle speed 8 mph or greater
^ EBCM internal relay on
^ Pump motor commanded on and then off
^ High voltage from low side of pump motor for 100ms when expected to be low.

ACTION TAKEN WHEN THE DTC SETS
^ ABS indicator lamp is fumed ON
^ ABS is disabled

NOTE: This Diagnostic Trouble Codes (DTC) is an Ignition Latched DTC which indicates the above is true until the ignition is turned to OFF (even if the cause of the DTC is intermittent).

DIAGNOSTIC AIDS
DTC C0068 is usually caused by a seized pump motor, but also can be caused by shorted pump motor windings or by poor power/ground at the 2-way EBCM connector. The pump motor is integral with the Brake Pressure Modular Valve (BPMV) assembly and cannot be separately serviced. The EBCM or BPMV must be replaced if these tests show the pump motor EBCM internal circuitry have failed.

NOTE: The J 39200 (or equivalent) test leads must be zeroed prior to making any resistance measurements. Refer to the J 39200 (or equivalent) users manual.

TEST DESCRIPTION
The numbers below refer to the numbers on the diagnostic chart.
2. Inspect the EBCM 2-way harness connector for damage.
3. Checks the resistance of the EBCM ground circuit at the 2-way connector.