Antilock Brake System - Non-Hybrid Greater than/Equal to 3900 kg (8600 lb) GVW (With JL4)

DTC C0245 (With JL4)

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 C0245 5A

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Wheel Speed Sensor Frequency Plausibility Failure

Circuit/System Description

The wheel speed sensor receives 12-volt reference from the electronic brake control module (EBCM) and provides a DC square wave signal back to the module. As the wheel spins, the EBCM uses the frequency of the square wave signal to calculate the wheel speed. The EBCM compares the wheel speed differences between one wheel and the others is greater than 25 percent a frequency error is determined.

Conditions for Running the DTC

* The ignition is ON.

* Brake is not applied.

* Vehicle is not cornering.

* No wheel spinning is detected.

* No wheel speed sensor faults exist.

* Ignition voltage is greater than 9.5 volts.

Conditions for Setting the DTC

Wheel speed differences between one wheel and the others is greater than 25 percent.

Action Taken When the DTC Sets

* The ABS indicator turns ON.

* The red brake indicator turns ON.

* The Stabilitrak indicator turns ON.

* The driver information center displays Service Traction Control.

* The electronic brake control module disables the antilock brake system, the traction control, the electronic stability control and the hill start assist for the duration of the ignition cycle.

Conditions for Clearing the DTC

* A current DTC clears when the diagnostic runs and passes.

* The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

* The DTC becomes history when the conditions for setting the DTC are no longer present.

Diagnostic Aids

* Faulty wheel speed sensor will not set this DTC.

* A vehicle using a space saver spare will not set this code.

Reference Information

Schematic Reference

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

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

ABS Description and Operation (Without JL4) Description and OperationABS Description and Operation (With JL4) 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. Inspect for one tire that has improper air pressure.

• If not all the same air pressure, adjust all the tires to the stated cold air pressure as identified on the tire placard or specification.

2. Confirm that all tires are of the proper size and that all are matching brands.

• If a mis-sized or non-matching brand tire is present, inform the customer that in order for the vehicle stability enhanced system to function normally, tires need to be a uniform size and rolling diameter.