GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2009 🢒 STS 🢒 Brakes 🢒 Antilock Brake System 🢒 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 04: Antilock Brake System (ABS) Enable Relay Contact Open 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 ON.
    • Ignition voltage is greater than 10 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 solenoids.

Actions Taken when the DTC Sets
    • The EBCM disables the antilock brake system (ABS), traction control and StabiliTrak for the duration of the ignition cycle.
    • A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present.
    • The EBCM clears the history DTC when a current DTC is not detected in 40 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 Testing
  1. Ignition OFF, disconnect the harness connector at the EBCM.
  2. Test for less than 1 ohm between the ground circuits listed below and ground.
    3. • Terminal 25
    • Terminal 1
    ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp illuminates between the B+ circuits listed below and ground.
    4. •  Terminal 38
    •  Terminal 13
    ⇒If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. If all circuits test normal, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming