GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

  1. Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
  2. Review Strategy Based Diagnosis for an overview of the diagnostic approach.
  3. Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C005A 00: Simultaneous Dropout of Both Wheel Speed Sensors on One Axle

Circuit/System Description

The wheel speed sensor receives ignition voltage 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.

Conditions for Running the DTC

    • Ignition ON.
    • Ignition voltage is greater than 10 volts.
    • Two other wheel speeds are greater than 0 km/h.

Conditions for Setting the DTC

Simultaneous Dropout of Both Wheel Speed Sensors on One Axle.

Actions Taken when the DTC Sets

    • The EBCM disables the antilock brake system (ABS) and StabiliTrak for the duration of the ignition cycle.
    • A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

    • The condition for setting the DTC is no longer present.
    • The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.

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

Verify that DTC C005A is not set.

If the DTC is set, refer to DTC C0035-C0050, C1207-C1210, C1221-C1228, or C1232-C1235