Circuit Description
As the wheel spins, the wheel speed sensor produces an alternating current (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
| • | The ignition is in the ON position. |
| • | Vehicle speed of 12 km/h (8 mph) or more. |
Conditions for Setting the DTC
The EBCM detects low output voltage of the wheel speed sensor.
Action Taken When the DTC Sets
The following actions occur:
| • | The EBCM disables the antilock brake system (ABS) and traction control system for the duration of the ignition cycle. |
| • | The ABS and TRAC OFF indicators turn ON. |
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
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 ring |
| • | An internal EBCM malfunction |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | |||||||||||
1 | Did you perform A Diagnostic System Check - ABS? | Go to Step 2 | |||||||||
2 |
Does the wheel speed sensor signal change as wheel is rotated faster? | Go to Step 3 | Go to Step 4 | ||||||||
3 |
Does the DTC reset? | Go to Step 4 | Go to Diagnostic Aids | ||||||||
4 | Inspect for poor connections at the harness connector of the wheel speed sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 5 | ||||||||
Test the wheel speed sensor circuits for the following:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 6 | |||||||||
6 | Inspect for poor connections at the harness connector for the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 7 | ||||||||
7 | Inspect the wheel speed sensor for damage. Is the wheel speed sensor damaged? | Go to Step 9 | Go to Step 8 | ||||||||
8 | Inspect the wheel speed sensor rotor for damage. Is the wheel speed sensor rotor damaged? | Go to Step 10 | Go to Step 11 | ||||||||
9 | Replace the wheel speed sensor. Refer to Front Wheel Bearing and Hub Replacement in Front Suspension. Did you complete the replacement? | Go to Step 12 | -- | ||||||||
10 | Replace the wheel speed sensor rotor. Refer to Front Wheel Bearing and Hub Replacement in Front Suspension. Did you complete the replacement? | Go to Step 12 | -- | ||||||||
11 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | Go to Step 12 | -- | ||||||||
12 |
Does the DTC reset? | Go to Step 2 | System OK | ||||||||
