C0201
DTC C0201
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC C0201 00
- Antilock Braking System Enable Relay Primary Circuit Malfunction
Circuit/System Description
Battery positive voltage is supplied to the Electronic Brake Control Module at all times through a 40 A fuse located in the underhood fuse block. The Electronic Brake Control Module uses this voltage to power the pump motor. The pump motor is an integral part of the Brake Pressure Modulator, while the Pump Motor Relay is integral to the Electronic Brake Control Module. The pump motor relay is not engaged during normal system operation. When the ABS, traction/stability operation is required the Electronic Brake Control Module activates the Pump Motor Relay and turns the pump motor ON.
Conditions for Running the DTC
* Ignition ON.
* Ignition voltage is greater than 8 V.
Conditions for Setting the DTC
The pump motor supply voltage is less than 4 V.
Action Taken When the DTC Sets
* The ABS indicator turns ON.
* The Traction/stability Control Indicator turns ON, if equipped with electronic stability control.
* The Electronic Brake Control Module disables the ABS, and the Traction/stability for the duration of the ignition cycle.
Conditions for Clearing the DTC
* The condition for setting the DTC is no longer present.
* The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
ABS Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF all vehicle systems OFF, disconnect the harness connector at the K17 Electronic Brake Control Module. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 omhs between each ground circuit terminal listed below and ground:
* Terminal 13
* Terminal 38
• If 10 omhs or greater
1. Ignition OFF
2. Test for less than 2 omhs in the ground circuit end to end.
• If 2 omhs or greater, repair the open/high resistance in the circuit.
• If less than 2 omhs, repair the open/high resistance in the ground connection.
• If less than 10 omhs
3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal 1 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 omhs in the B+ circuit end to end.
• If 2 omhs or greater, repair the open/high resistance in the circuit.
• If less than 2 omhs, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the Q5 Brake Pressure Modulator.
• If the test lamp illuminates
5. Replace the Q5 Brake Pressure Modulator.
6. Verify the DTC does not set while operating the vehicle within the Conditions for Running the DTC.
• If the DTC sets
Replace the K17 Electronic Brake Control Module.
• If the DTC does not set
7. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Brake Pressure Modulator Valve Replacement Brake Pressure Modulator Valve Replacement
* Control Module References Control Module References for Electronic Brake Control Module replacement, programming and setup