Circuit Description
As a toothed ring passes by the wheel speed sensor, changes in the electromagnetic field cause the wheel speed sensor to produce an alternating current (AC) voltage signal whose frequency is proportional to the wheel speed. The magnitude of this signal is directly related to wheel speed and the proximity of the wheel speed sensor to the toothed ring often referred to as the air gap.
Conditions for Running the DTC
This test checks that the left front wheel speed is equal to 0 km/h (0 mph) for greater than 6 km/h (3.8 mph).
Conditions for Setting the DTC
| • | The tooth ring is missing. |
| • | The air gap exceeds the required specifications. |
Action Taken When the DTC Sets
This is a critical operational fault. The antilock brake system (ABS) is disabled and the ABS warning lamp is turned on. The proportioning is operation.
Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
| • | A short to ground or a short to voltage in the wheel speed sensor circuitry |
| • | An open or high resistance in the wheel speed sensor circuitry |
| • | A malfunctioning wheel speed sensor |
| • | A malfunctioning wheel speed sensor rotor |
| • | An internal electronic brake control module (EBCM) malfunction |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | |||||||||
1 |
Is the repair complete? | System OK | Go to Step 2 | ||||||
2 | Replace the EBCM. Is the repair complete? | System OK | -- | ||||||
