DTC C1218 Pump Motor Circuit Shorted to Voltage. Buick Century (China) 2000

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2000 🢒 Century (China) 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1218 Pump Motor Circuit Shorted to Voltage

ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Power Distribution Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

Circuit Description

The pump motor is an integral part of the Brake Pressure Modulator Valve (BPMV). The electronic brake control relay supplies voltage to the solenoid valves and pump motor. This voltage is referred to as the system voltage. The electronic brake control relay, located in the EBCM, is activated whenever the ignition switch is in the RUN position and no faults are present. The electronic brake control relay remains engaged until the ignition switch is turned off or a failure is detected.

Conditions for Running the DTC

•	The pump motor is commanded ON.

•	The system voltage is greater than 8.0 volts.

Conditions for Setting the DTC

Either of the following conditions are present for greater than 0.16 seconds.

•	The voltage across the pump motor is less than 8.0 volts and the commanded pump motor voltage is greater than or equal to the system voltage.

•	The voltage across the pump motor is 3.0 volts less than and the pump motor voltage and the commanded pump voltage is greater than or equal to the system voltage.

Action Taken When the DTC Sets

•	ABS/TCS is disabled.

•	ABS/TCS indicators are turned on.

Conditions for Clearing the DTC

•	Condition for DTC is no longer present and scan tool clear DTC function is used.

•	100 ignition cycles have passed with no DTCs detected.

Step	Action	Value(s)	Yes	No
1	Did you perform the ABS Diagnostic System Check?	--	Go to Step 2	Go to Diagnostic System Check - ABS
2	Use the scan tool in order to clear the DTCs. Command the pump motor ON with the Automated Bleed function using the scan tool. Does the DTC reset?	--	Go to Step 3	Go to Testing for Intermittent Conditions and Poor Connections
3	Remove the EBCM from the BPMV. Refer to Electronic Brake Control Module Replacement . Inspect the EBCM to BPMV connector for conditions which could cause an intermittent, such as damage, corrosion, poor terminal contact, or presence of brake fluid. Is connector OK and cavity free of brake fluid?	--	Go to Step 5	Go to Step 4
4	If connector corrosion or damage is evident, replace BPMV and/or EBCM as necessary. If brake fluid is present, replace both BPMV and EBCM. Refer to Brake Pressure Modulator Valve Replacement and Electronic Brake Control Module Replacement . Did you complete the repair?	--	Go to Step 10	--
5	Connect the EBCM harness to the EBCM with the BPMV still separated. Connect a test lamp between the pump motor circuits, internal EBCM side, using the J 35616 Connector Test Adapter Kit . Command the pump motor ON with the Automated Bleed function using the scan tool. Does the test lamp illuminate?	--	Go to Step 9	Go to Step 6
6	Turn OFF the ignition. Disconnect the EBCM connector. Connect the J 39700 Universal Pinout Box using the J 39700-99 Cable Adapter to the EBCM harness connector only. Measure the resistance between the pump motor ground circuit of the Universal Pinout Box and a known good ground. Does the resistance measure within the specified value?	0-2 ohms	Go to Step 8	Go to Step 7
7	Repair the open or high resistance in the pump motor ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	--	Go to Step 10	--
8	Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair?	--	Go to Step 10	--
9	Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Did you complete the repair?	--	Go to Step 10	--
10	Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?	--	Go to Step 2	System OK