Buick Regal: DTC C0116

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 Descriptors

DTC C0116

Pump Motor Relay Circuit

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Circuit/System Description

The pump motor is an integral part of the brake pressure modulator valve assembly, 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 control or stability control 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.

Conditions for Setting the DTC

• The pump motor relay has an internal failure
• The pump motor relay voltage is greater than threshold.

Action Taken When the DTC Sets

• The electronic brake control module disables the ABS, traction control, stability control and hill start assist for the duration of the ignition cycle.
• The ABS warning indicator turns ON.
• The traction control/stability control-active indicator turns ON.

Conditions for Clearing the DTC

• A current DTC clears when the diagnostic runs and passes.
• The electronic brake control module will turn OFF the indicators in the next ignition cycle.

Reference Information

Schematic Reference

Antilock Brake System Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

ABS Description and Operation

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify that DTC C0110 is not set.

• If DTC C0110 is set

Refer to DTC C0110 to diagnose that DTC prior to this diagnostic.

• Go to next step: If DTC C0110 is not set

3. Replace the K17 Electronic Brake Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Electronic Brake Control Module replacement, programming and setup.

DTC C0121

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 C0121

Valve Relay Circuit Malfunction

For symptom byte information refer to Symptom Byte List.

Diagnostic Fault Information

Circuit/System Description

The valve relay is an integral part of the electronic brake control module (EBCM), while the solenoid valves are integral to the brake pressure modulator valve assembly. The valve relay is engaged during normal system operation and provides voltage to the solenoid valves. When the ABS control operation is required, the EBCM controls the solenoid valves by providing ground to the active solenoid valves.

Conditions for Running the DTC

• Vehicle speed is greater than 6 km/h (4 MPH) with the brake pedal not applied.

  OR

• Vehicle speed is greater than 15 km/h (9 MPH) and the brake pedal is not actuated.

Conditions for Setting the DTC

• The EBCM is requesting valve activation and the relay output voltage is low.
• The EBCM is not requesting valve activation and the relay output voltage is B+.
• The EBCM detects 3 or more solenoid valve circuits are open or shorted during the self-test.
• A malfunction exists within the EBCM.

Action Taken When the DTC Sets

• The EBCM disables the ABS for the duration of the ignition cycle.
• The ABS indicator turns ON.

Conditions for Clearing the DTC

• A current DTC clears when the diagnostic runs and passes.
• The EBCM will turn OFF the indicator and enable the system functions in the next ignition cycle.

Reference Information

Schematic Reference

Antilock Brake System Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

ABS Description and Operation

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, command the ABS Solenoid Valves On and Off with the scan tool. The solenoid valves should turn ON and OFF.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the K17 Electronic Brake Control Module (EBCM).

2. Test for less than 5 Ω between the ground circuit terminals listed below:

• Ground circuit terminal 14 and ground.
• Ground circuit terminal 46 and ground.
• If greater than 5 Ω

Test/repair the ground circuit for an open/high resistance.

• Go to next step: If less than 5 Ω

Go to next step: Replace the K17 Electronic Brake Control Module

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup and programming.

READ NEXT: