• | 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. |
Circuit | Short to Ground | Open or High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Left Front Sensor Signal | C0035 00 | C0035 00 | C0035 00 | C0035 0F, C0035 18, C0035 5A |
Left Front Sensor Low Reference | C0035 00 | C0035 00 | C0035 00 | C0035 0F, C0035 18, C0035 5A |
Right Front Sensor Signal | C0040 00 | C0040 00 | C0040 00 | C0040 0F, C0040 18, C0040 5A |
Right Front Sensor Low Reference | C0040 00 | C0040 00 | C0040 00 | C0040 0F, C0040 18, C0040 5A |
Left Rear Sensor Signal | C0045 00 | C0045 00 | C0045 00 | C0045 0F¹, C0045 18, C0045 5A |
Left Rear Sensor Low Reference | C0045 00 | C0045 00 | C0045 00 | C0045 0F¹, C0045 18, C0045 5A |
Right Rear Sensor Signal | C0050 00 | C0050 00 | C0050 00 | C0050 0F¹, C0050 18, C0050 5A |
Right Rear Sensor Low Reference | C0050 00 | C0050 00 | C0050 00 | C0050 0F¹, C0050 18, C0050 5A |
¹Damaged rear wheel speed sensor ring can cause code to set. |
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.
• | The ignition is ON. |
• | Ignition voltage is greater than 8 volts. |
• | The ignition is ON. |
• | Ignition voltage is greater than 8 volts. |
• | The brake pedal is not pressed. |
• | A DTC is not set for the other wheel speed circuit on the same axle. |
• | The ignition is ON. |
• | Ignition voltage is greater than 8 volts. |
• | The brake pedal is not pressed. |
• | No other wheel speed circuit DTCs are set. |
• | At least two other wheel speeds are not 0 km/h. |
• | An open is detected on the wheel speed sensor signal circuit. |
• | A short to ground is detected on the wheel speed sensor signal circuit. |
• | A short to voltage is detected on the wheel speed sensor signal circuit. |
Detects a missing sensor signal when the vehicle has been in motion with all sensors working.
• | All wheel speeds have been read as greater than 12.9 km/h (8 mph). |
• | One wheel speed suddenly reads 0 km/h (0 mph) within 15 msec. |
• | Vehicle velocity remains greater than 12.9 km/h (8 mph). |
OR
• | Any wheel speed changes by 17.7 km/h (11 mph) or more in 0.01 second. |
• | Vehicle velocity remains greater than 12.9 km/h (8 mph). |
Detects a missing sensor signal (or signals) when the vehicle accelerates from a standstill.
• | One wheel speed is less than 20 percent of the maximum of the others for 5 seconds. |
• | At least one of the remaining wheel speeds are greater than 12.9 km/h (8 mph). |
• | There has been no wheel acceleration/deceleration exceeding 21.9 mph/sec. |
OR
• | The 2 wheel speed sensor inputs are less than 20 percent of the maximum of the others for 120 seconds. |
• | At least one of the remaining wheel speeds are greater than 12.9 km/h (8 mph). |
• | There has been no wheel acceleration/deceleration exceeding 21.9 mph/sec. |
• | The EBCM disables the Antilock Brake System (ABS)/Traction Control System (TCS)/Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle. |
• | The dynamic rear proportion (DRP) does not function optimally. |
• | The ABS indicator turns ON. |
• | The Traction Control indicator turns ON. |
• | The driver information center (DIC) displays the Service Stability System message. |
• | The condition for setting the DTC is no longer present and the DTC is cleared with a scan tool. |
• | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
• | A damaged rear wheel speed sensor ring can cause failure type byte 04 (Erratic Signal) to set. |
• | If 2 or more wheel speed sensors are inoperative diagnose each wheel speed sensor individually. |
If the customer comments that the ABS indicator is ON only during moist environmental conditions: rain, snow, vehicle wash, etc., inspect the wheel speed sensor wiring for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure:
Antilock Brake System Schematics
Control Module References for scan tool information
With scan tool installed drive the vehicle in a straight line at a speed greater than 8 km/h (5 mph), all wheel speed sensors should read the same miles per hour.
Important: Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors.
⇒ | If over 0 volt, repair short to voltage in sensor signal circuit or the low reference circuit. |
⇒ | If less than infinite ohms, repair short to ground in the sensor signal or the low reference circuit. |
⇒ | If greater than 1350 ohms test for an open/high resistance in the circuit or faulty wheel speed sensor. |
⇒ | If less than 850 ohms test for a short between the circuits or faulty wheel speed sensor. |
⇒ | If not within the specified range, replace the wheel speed sensor. |
⇒ | If less than the specified value, replace the appropriate wheel speed sensor. |
⇒ | If less than the specified range, replace the wheel speed sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for EBCM replacement, setup, and programming |