Buick Regal: DTC C1207, C1208, C1221, C1222, C1225, C1226, C1232, or C1233

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 C1207 00

Left Front Wheel Speed Sensor Circuit High Input Malfunction

DTC C1208 00

Right Front Wheel Speed Sensor Circuit High Input Malfunction

DTC C1221 00

Left Front Wheel Speed Sensor Circuit Malfunction

DTC C1222 00

Right Front Wheel Speed Sensor Circuit Malfunction

DTC C1225 00

Left Front Wheel Speed Sensor Circuit Performance Malfunction

DTC C1226 00

Right Front Wheel Speed Sensor Circuit Performance Malfunction

DTC C1232 00

Left Front Wheel Speed Sensor Circuit Low Input Malfunction

DTC C1233 00

Right Front Wheel Speed Sensor Circuit Low Input Malfunction

Circuit/System Description

The wheel speeds are detected by active wheel speed sensors and encoder rings. The encoder ring consists of permanent magnets. Each wheel speed sensor receives 12 V reference voltage from the electronic brake control module and provides an alternating current square wave signal to the electronic brake control module. As the wheel spins, the electronic control module uses the frequency of the square wave signal to calculate the wheel speed. The electronic brake control module sends the wheel speed information as a high speed controller area network (CAN) serial data message.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

A supervised periodic message indicates the wheel speed serial data has not been received.

Action Taken When the DTC Sets

Specific subsystems will not function or operate in degraded mode.

Conditions for Clearing the DTC

• The DTC clears when the diagnostic runs and passes.
• The history DTC will clear after 40 consecutive fault-free drive cycles have occurred.

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 C0035, C0040, C0045, or C0050 is not set.

• If any listed DTC is set

Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

• Go to next step: If none of the listed DTCs is set

3. Replace the K17 Electronic Brake Control Module.

4. Verify the DTC does not set while operating the vehicle under the Conditions for Running the DTC.

• If the DTC sets

Replace the module that set the DTC.

• Go to next step: If the DTC does not set

5. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References provides information for control module replacement, programming and setup.

DTC C124F or C1250-C1254

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 C124F

Lateral Acceleration Sensor Circuit Low Voltage

DTC C1250

Lateral Acceleration Sensor Circuit High Voltage

DTC C1251

Lateral Acceleration Sensor Performance

DTC C1252

Longitudinal Acceleration Sensor Circuit Low Voltage

DTC C1253

Longitudinal Acceleration Sensor Circuit High Voltage

DTC C1254

Longitudinal Acceleration Sensor Performance

For symptom byte information refer to Symptom Byte List.

Circuit/System Description

The yaw rate, lateral acceleration and longitudinal acceleration sensors are combined into one multi-axis acceleration sensor, internal to the inflatable restraint sensing and diagnostic module. The multi-axis acceleration sensor communicates with the electronic brake control module and trans control module via serial data. The electronic brake control module activates the stability control function depending on the multi-axis acceleration sensor input. The inflatable restraint sensing and diagnostic module uses the multi-axis acceleration sensor to determine if the vehicle is in a roll over or near collision incident. The transmission control module sets these DTCs.

Conditions for Running the DTC

Vehicle speed is greater than 16 km/h (10 MPH).

Conditions for Setting the DTC

The transmission control module detects a fault that prevents it from performing a hill hold start assist function.

Action Taken When the DTC Sets

• The air bag indicator turns ON.
• The traction/stability control indicator turns ON.
• The electronic brake control module disables the stability control and the hill hold start assist for the duration of the ignition cycle.

Conditions for Clearing the DTC

• The DTC clears when the diagnostic runs and passes.
• The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

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 no other DTCs are set.

• If any other DTCs are set

Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

• Go to next step: If no other DTCs are set

3. Replace the K71 Transmission Control Module.

4. Verify that 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.

• Go to next step: If the DTC does not set

5. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

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

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