DTC C0267 or C0268 and C067 or C068 Pump Motor Circuit Open/Shorted. Chevrolet S10 Pickup

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2000 🢒 S10 Pickup - 4WD 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C0267 or C0268 and C067 or C068 Pump Motor Circuit Open/Shorted

DTC C0267 or C0268 and C067 or C068 Pump Motor Circuit Open/Shorted 310 ABS

Circuit Description

The EBCM internal relay supplies battery voltage to the pump motor. The EBCM applies the ground needed for pump motor activation. The low side of the pump motor has a feedback circuit to the EBCM microprocessor. 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 IPC bulb check is complete.

•	The vehicle is moving at a speed greater than 5 km/h (3 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

•	Repair the condition(s) responsible for setting the DTC.

•	Use a scan tool in order to clear the DTC.

Diagnostic Aids

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

Test Description

The number below refers to the step number on the diagnostic table.

Separate the EBCM from the BPMV in order to access the pump motor pigtail connector. Refer to Electronic Brake Control Module Replacement . This step tests if the EBCM is capable of activating the pump motor. Replace the EBCM if DTC C0267 sets while the ABS motor test is performed. DTC C0268 may set while this test is performed even if the EBCM is functioning properly.

Step	Action	Value(s)	Yes	No
Schematic Reference: Antilock Brake System Schematics
1	Did you perform the ABS Diagnostic System Check?	--	Go to Step 2	Go to Diagnostic System Check
2	Use a scan tool in order to clear the DTC(s). Use the scan tool in order to perform an ABS Motor test, commanding the pump motor On and Off. Does the DTC set?	--	Go to Step 3	Go to Diagnostic Aids
3	Turn the ignition OFF. Disconnect the 2-way pump motor pigtail connector from the EBCM. Use the connector test adaptor kit J 35616-A in order to connect a test lamp between the pump motor circuits at the pump motor connector of the EBCM. Turn the ignition ON. Use the scan tool in order to clear the DTC. Use the scan tool in order to command the ABS pump motor On and Off. Does the test lamp illuminate and turn off with each command?	--	Go to Step 4	Go to Step 5
4	Inspect for poor connections at the pump motor pigtail connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	--	Go to Step 7	Go to Step 6
5	Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Important: Perform the Tire Size Calibration procedure. Did you complete the replacement?	--	Go to Step 7	--
6	Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Did you complete the replacement?	--	Go to Step 7	--
7	Use a scan tool in order to clear the DTC. Use the scan tool in order to perform an ABS Motor test. Does the DTC set?	--	Go to Step 3	System OK

DTC C0267 or C0268 and C067 or C068 Pump Motor Circuit Open/Shorted 325 ABS