GM Service Manual Online
For 1990-2009 cars only

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 C0245 00: Wheel Speed Sensor Frequency Error

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Wheel Speed Sensor Frequency Circuit

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C0245 00

Circuit/System Description

As the wheel spins, the wheel speed sensor produces an AC signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.

Conditions for Running the DTC

    • Ignition ON.
    • Ignition voltage is greater than 9 volts.
    • Vehicle must be moving at a speed less than 14.5 km/h (9 mph).
    • No wheel speed sensor faults exist.
    • Brake is not applied.
    • Vehicle is not cornering.
    • No wheel spinning is detected.

Conditions for Setting the DTC

    • Wheel speed differences between one wheel and the others is greater than 25 percent.
    •  This DTC will set when the EBCM cannot specifically identify which wheel speed sensor (WSS) is causing the malfunction. If the EBCM can identify the specific WSS causing the malfunction, DTC C0245 will become a history DTC, and the DTC associated with the sensor DTC C0036,C0041, C0046, C0051, or DTC C0056 will be set concurrent with DTC C0245.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • Antilock brake system (ABS), traction control system (TCS) and vehicle stability enhancement system (VSES) are inhibited.
    • The ABS indicator illuminates.
    •  The Stability OFF indicator illuminates.
    •  The red BRAKE warning indicator illuminates.

Conditions for Clearing the MIL/DTC

The condition for the DTC is 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.
    •  If the customers comments reflect that the amber ABS/TCS indicator is on only during moist environmental conditions (rain, snow, vehicle wash), inspect all the wheel speed sensor circuitry for signs of water intrusions. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure:
        1.  Spray the suspected area with a five percent saltwater solution. Add 2 teaspoons of salt to 12 ounces of water to make five percent saltwater solution.
        2. Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 40 km/h (25 mph) for at least 30 seconds.
        3.  If the DTC returns, replace the suspected harness.

If an intermittent malfunction exists refer to Testing for Intermittent Conditions and Poor Connections .

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

    •  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

Inspect for one tire that has improper air pressure or improper size.