GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 STS 🢒 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 04: 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

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.

Action Taken When the DTC Sets
    • The EBCM disables the ABS/dynamic rear proportion (DRP) for the duration of the ignition cycle.
    • The ABS indicator turns ON.
    • The red brake warning indicator turns ON.

Conditions for Clearing the DTC
    • The condition for setting the DTC is no longer present.
    • 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 Reference

ABS Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References

Circuit/System Verification

With scan tool installed ignition ON clear the DTCs, command the ABS solenoids ON and OFF with a scan tool. Monitor the operation of ABS solenoids turn on and off. Also, drive the vehicle in a straight line at a speed greater than 20 km/h (13 mph). If the DTC did not set as a current DTC see diagnostic aids.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the EBCM.
  2. Test for less than 1.0 ohm of resistance from ground circuit terminal E (w/o JL7) or 1 (w/ JL7) and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Test for less than 1.0 ohm of resistance from ground circuit terminal F (w/o JL7) or 25 (w/ JL7) and ground.
    4. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A (w/o JL7) or 38 (w/ JL7) and ground.
    5. ⇒If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  5. Verify that a test lamp illuminates between the B+ circuit terminal B (w/o JL7) or 13 (w/ JL7) and ground.
    6. ⇒If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. If all circuits test normal, test or replace the EBCM assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming