DTC C0201, C120D, or C120E
Diagnostic Instructions
DTC Descriptors
DTC C0201 04: Antilock Brake System Enable Relay Primary Circuit Open
DTC C120D 00: Traction Control Power Switch Circuit Open
DTC C0201 0E: Antilock Brake System Enable Relay Contact Circuit Low Resistance
DTC C120E 00: Traction Control Power Switch Circuit Shorted
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
B+
| C0201 04
| C0201 04
| --
| --
|
Ground Terminal 13
| -
| C056D 00, C12DA 00, C12D7 00
| --
| --
|
Ground Terminal 38
| -
| U0129 00, U1833 00
| --
| --
|
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 under-bonnet 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 antilock brake system or traction control system operation is required the electronic brake control module activates the pump motor relay and turns the pump motor ON.
Conditions for Running the DTC
C0201 04 or C120D 00
• | Ignition voltage is greater than 10 V. |
• | The solenoid relay is commanded ON. |
C0201 0E or C120E 00
• | Ignition voltage is greater than 10 V. |
• | The solenoid relay is commanded OFF. |
Conditions for Setting the DTC
C0201 04 or C120D 00
• | The electronic brake control module detects an open in the B+ circuit. |
• | The engine control module detects the traction control power switch circuit is open. |
C0201 0E or C120E 00
• | The electronic brake control module detects an internal power switch shorted. |
• | The engine control module detects the traction control power switch circuit is shorted. |
Action Taken When the DTC Sets
• | The ABS indicator turns ON. |
• | The traction control/stability control indicator turns ON. |
• | The Service StabiliTrak message is displayed on the driver information centre. |
• | The electronic brake control module disables the traction control and the electronic stability control for the duration of the drive 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 drive cycles have occurred. |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
ABS Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Vehicle 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.
- Test for less than 10 Ω between the ground circuit terminals listed below and ground:
2.2. | Test for less than 2 Ω in the ground circuit end to end. |
⇒ | If 2 Ω or greater, repair the open/high resistance in the circuit. |
⇒ | If less than 2 Ω, repair the open/high resistance in the ground connection. |
- Vehicle in Service Mode, verify a test lamp illuminates between the B+ circuit terminal 25 and ground.
⇒ | If the test lamp does not illuminate and the circuit fuse is good |
3.2. | Test for less than 2 Ω in the B+ circuit end to end. |
⇒ | If 2 Ω or greater, repair the open/high resistance in the circuit. |
⇒ | If less than 2 Ω, 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 |
3.4. | 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 K17 electronic brake control module. |
⇓ | If the test lamp illuminates |
- Replace the K17 electronic brake control module.
- Verify the DTC does not set while operating the vehicle under the Conditions for Running the DTC.
| Replace the Q5 brake pressure modulator. |
⇓ | If the DTC does not set |
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
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