C122E

DTC C122E

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 Descriptor

DTC C122E 00

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Tire Size Mismatch 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 ignition 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 brake 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 via serial data.

Conditions for Running the DTC

Vehicle speed is greater than 14 km/h (9 MPH).

Conditions for Setting the DTC

The engine control module detects wheel speed differences between one wheel and the others.

Action Taken When the DTC Sets

Specific subsystems will not function or operate in degraded mode.

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 ignition cycles have occurred.

Reference Information

Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems

Connector End View Reference

Component Connector End Views Sunshade - Left (DH6)

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 Verification

1. Verify that all tires have the proper air pressure.

• If not the proper air pressure

Adjust all tire air pressures to the stated cold air pressure as identified on the tire placard or specification.

• If the proper air pressure

2. Verify that all tires are of uniform size and matching brand.

• If not of uniform size or matching brand

1. Replace the miss-sized or non-matching brand tire.

2. Ignition ON.

3. Verify the DTC does not set while operation the vehicle under the Conditions for Running the DTC.

• If the DTC sets, replace the K17 electronic brake control module.

• If the DTC does not set

4. All OK.

• If all tires are of uniform size and matching brand

3. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

Control Module References Control Module References for electronic brake control module replacement, programming and setup