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 : Antilock Brake System (ABS) Enable Relay Contact CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
B+ | C0201 | C0201 | -- | C0201 |
Ground | -- | C0201 | -- | C0201 |
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.
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 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 indicator may be displayed. |
Conditions for Clearing the DTC
| • | The condition for setting the DTC is no longer present. |
| • | The EBCM 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
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module Referencesfor 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
Important: It is recommend that the defective components be replaced, and not the complete brake master cylinder assembly.
- Ignition OFF, disconnect the X1, X2 harness connectors at the EBCM.
- Test for less than 1 ohm between the ground circuit terminal listed below and ground.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal listed below and ground.
- If all circuits test normal, replace the EBCM/BPMV assembly.
| • | Terminal 4 X1 |
| • | Terminal 1 X2 |
| • | Terminal 32 X2 |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| • | Terminal 2 X1 |
| • | Terminal 2 X2 |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, replace the EBCM/BPMV. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for EBCM replacement, setup, and programming
