GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0201 00: Antilock Brake System (ABS) Enable Relay Contact Circuit

Circuit/System Description

The EBCM controls it's internal valve relay to command the valve solenoids ON or OFF.

Conditions for Running the DTC

    • Ignition voltage is greater than 10 volts.
    • The solenoid relay is commanded ON.

Conditions for Setting the DTC

    • The EBCM detects no change when commanding the valve relay ON or OFF.
    • The EBCM detects a stuck open solenoid valve relay or an open circuit between the solenoid valve relay and solenoid valves.

Action Taken When the DTC Sets

    • The EBCM disables the antilock brake system (ABS)/traction control system (TCS).
    • A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

    • The condition for setting the DTC is no longer present.
    • The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, verify that DTC C0201 is not set.

If DTC is set, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming