C120E

DTC C0201, C120D, or C120E

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 Descriptors
DTC C0201 04
- Antilock Brake System (ABS) Enable Relay Contact Circuit Open

DTC C120D
- Traction Control Power Switch Circuit Open

DTC C0201 0E
- Antilock Brake System (ABS) Enable Relay Contact Circuit Resistance Below Threshold

DTC C120E
- Traction Control Power Switch Circuit Shorted

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

C0201 04 or C120D
* Ignition voltage is greater than 10 V.
* The solenoid relay is commanded ON.

C0201 0E or C120E
* Ignition voltage is greater than 10 V.
* The solenoid relay is commanded OFF.

Conditions for Setting the DTC

C0201 04 or C120D
* The EBCM detects an open in the circuits to the solenoid valve relay.
* The EBCM detects a stuck open solenoid valve relay.

C0201 0E or C120D
* The EBCM detects an short to battery in the circuits to the solenoid valve relay.
* The EBCM detects a stuck closed solenoid valve relay.

Action Taken When the DTC Sets

* The EBCM disables the antilock brake system (ABS) and the vehicle stability enhancement system for the duration of the ignition cycle.
* A driver information center 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 40 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 Hybrid/EV Battery Pack X1 A4
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 EBCM. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohm between the ground circuit terminals listed below and ground:

* Terminal 13
* Terminal 38

• If 10 ohm or greater

1. Ignition OFF
2. Test for less than 2 ohm in the ground circuit end to end.

• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, repair the open/high resistance in the ground connection.

• If less than 10 ohm

3. Ignition ON.
4. Verify that a test lamp illuminates between B+ circuit terminals listed below and ground:

* Terminal 1
* Terminal 25

• If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF
2. Test for less than 2 ohm in the B+ circuit end to end.

• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, 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 BPMV.

• If the test lamp illuminates

5. Ignition OFF.
6. Remove the K17 EBCM from the Q5 BPMV.
7. Inspect the K17 EBCM to Q5 BPMV connector for the conditions listed below:

* Damage
* Corrosion
* Presence of brake fluid

• If connector corrosion or damage is evident, replace Q5 BPMV and/or K17 EBCM as necessary.
• If brake fluid is present, replace both Q5 BPMV and K17 EBCM.

• If the K17 EBCM to Q5 BPMV connector is OK

8. Connect the harness connector at the K17 EBCM with the Q5 BPMV still separated.
9. Connect a test lamp between the pump motor control and ground circuit terminals, ignition ON.
10. Verify the test lamp turns ON and OFF when commanding the ABS Motor Test ON and OFF with a scan tool.

• If the test lamp is always OFF or always ON
Replace the K17 EBCM.

• If the test lamp turns ON and OFF

11. Replace the Q5 BPMV.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Electronic Brake Control Module with Brake Pressure Modulator Valve Replacement Electronic Brake Control Module with Brake Pressure Modulator Valve Replacement
* Control Module References Control Module References for EBCM replacement, programming and setup