GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Lucerne 🢒 DTC 🢒 DTC C0201

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: Antilock Brake System (ABS) Enable Relay Contact Circuit

Circuit/System Description

The solenoid relay, located within the electronic brake control module (EBCM), supplies battery voltage to all of the valve solenoids.

Conditions for Running the DTC
    • Ignition voltage is greater than 9.5 volts.
    • The solenoid relay is commanded ON.

Conditions for Setting the DTC
    • The EBCM detects an open in the battery positive voltage circuit to the solenoid valve relay.
    • 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)/dynamic rear proportion (DRP)/Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle.
    • The ABS indicator turns ON.
    • The Traction Control indicator turns ON.
    • The driver information center (DIC) displays the SERVICE ABS/TRACTION message.
    • The DIC displays the PANIC BRAKE ASSIST message.

Conditions for Clearing the DTC
    • The condition for setting the DTC is no longer present and the DTC is cleared with a scan tool.
    • The EBCM automatically 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

Antilock Brake System Connector End Views

Electrical Information Reference

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

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

With the scan tool, access the ABS special functions menu and perform the ABS Motor test. The pump motor should function and no DTCs should be set.

Circuit/System Testing
  1. Test for an open or a short to ground in the solenoid valve battery positive voltage circuit. Verify no open or a short to ground is found.
    2. ⇒If open or a short to ground is found repair circuit.
  2. Replace the EBCM/brake pressure modulator valve (BPMV) assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming