C0268

C0267 or C0268 and C067 or C068

Circuit Description
The EBCM applies the ground needed for pump motor activation. The low side of the pump motor has a feedback circuit to the EBCM. When the pump motor is commanded off, feedback voltage is high. When the pump motor is winding down after being commanded on and then off, feedback voltage is low due to the back-EMF generated in the motor windings as the rotor turns. The feedback voltage then rises correspondingly as the rotor slows to a stop and the back-EMF diminishes.

Conditions for Running the DTC
^ The ignition is ON.
^ The vehicle speed is greater than 6 km/h (4 mph).

Conditions for Setting the DTC
C0267
The EBCM detects low feedback voltage from the pump motor 2 seconds after the pump motor is commanded off.

C0268
The EBCM detects high feedback voltage from the pump motor 5 milliseconds after the pump motor is commanded off.

Action Taken When the DTC Sets
^ The ABS indicator is commanded on.
^ The ABS is disabled for the remainder of the ignition cycle.

Conditions for Clearing the DTC
^ The condition(s) responsible for setting the DTC is no longer present.
^ A scan tool is used in order to clear the DTC.

Diagnostic Aids
Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Intermittent and Poor Connections, Connector Repairs and Wiring Repairs.

Test Description

The number below refers to the step number on the diagnostic table.
3. This step tests if the EBCM is capable of activating the pump motor. Replace the EBCM if DTC C0267 will not clear while the test lamp is connected. DTC C0268 may set while this test is performed even if the EBCM is functioning properly.