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For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2008 🢒 H2 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 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 00: Antilock Brake System (ABS) Enable Relay Contact Circuit

Circuit/System Description

The solenoid and pump motor relay are located within the electronic brake control module (EBCM). The solenoid relay supplies battery voltage to all of the valve solenoids. Three pump motor relays supply battery positive voltage to the pump motor when the EBCM commands the pump motor on.

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

Conditions for Setting the DTC

One or more of the following conditions exists:

    • 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.
    • The EBCM detects an open in the battery positive voltage circuit to the solenoid valve relay.
    • The EBCM detects that one or more of the pump motor relays is off when commanded on.

Action Taken When the DTC Sets
    • The EBCM disables the Antilock Brake System (ABS)/Traction Control System (TCS)/Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle.
    • A DIC message and/or a warning message may be displayed.

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

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

With the scan tool, access the ABS special functions menu and perform the Solenoid Test and ABS Motor test. The pump motor and solenoids should function without setting DTCs.

Circuit/System Testing
  1. Disconnect the EBCM harness connector. Connect a test lamp to ground, at the EBCM harness connector touch the test lamp probe to each of the 3 battery positive voltage circuits. The test lamp should illuminate on all 3 circuits.
    2. ⇒If the test lamp does not illuminate on one of the battery positive voltage circuits, repair open or short to ground on the suspected circuit.
  2. Connect a test lamp to battery positive voltage, at the EBCM harness connector touch the test lamp probe to each of the 3 ground circuits. The test lamp should illuminate on all 3 circuits.
    3. ⇒If the test lamp does not illuminate on one of the ground circuits, repair open or short to voltage on the suspected circuit.
    ⇒If no wiring faults can be found, 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 and BPMV replacement, setup, and programming