C0201

DTC C0201

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 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 ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for EBCM


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 terminal . Verify no open or a short to ground is found.

• 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 (Verification Tests) after completing the diagnostic procedure.

* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming
* Brake Pressure Modulator Valve Replacement (Service and Repair)