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.
• | Ignition switch is in the RUN position. |
• | The rear wheel speed sensor signal is greater than 13 km/h (8 mph). |
The corresponding wheel speed sensor signal is less than 6 km/h (4 mph) for 5 seconds (120 seconds in order to set multiple missing sensor DTCs).
• | The ABS indicator lamp turns on. |
• | The ABS is disabled for as long as the malfunction is present. |
• | If DTC C0222 and DTC C0226 are both set, or if DTC C0236 is set with either of these DTCs the BRAKE indicator is also commanded ON. |
• | Repair the condition(s) responsible for setting the DTC. |
• | Use a scan tool in order to clear the DTC. |
Thoroughly inspect any connection or circuitry that is suspected of causing an intermittent malfunction. Inspect for the following conditions:
• | Backed out terminals |
• | Improper mating |
• | Broken locks |
• | Corrosion |
• | Improperly formed or damaged terminals |
• | Poor terminal-to-wiring connections |
• | Physical damage to the wiring harness |
• | Wiring Broken inside the insulation |
If the customer's concern is that the ABS indicator lamp is on only during humid conditions such as rain, snow or vehicle wash, thoroughly inspect all wheel speed sensor circuits for signs of water intrusion. Use the following procedure:
If the DTC returns, replace the suspected harness.
When inspecting a wheel speed sensor, inspect the sensor terminals for corrosion. If evidence of corrosion exists, replace the wheel speed sensor. Refer to Wheel Speed Sensor Replacement
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check |
2 |
Does the DTC set? | -- | Go to Step 3 | Go to Diagnostic Aids |
3 |
Does the resistance measure within the specified range? | 1575-3850ohms | Go to Step 4 | Go to Step 8 |
4 |
Does the AC voltage measure greater than the specified value? | 50 mV | Go to Step 5 | Go to Step 8 |
5 | 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 10 | Go to Step 6 |
6 | 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 10 | Go to Step 7 |
7 | Inspect for poor connections at the harness connector for the 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 10 | Go to Step 9 |
8 | Replace the wheel speed sensor. Refer to Wheel Speed Sensor Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- |
9 |
Important: Perform the tire size calibration in Scan Tool Diagnostics. Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- |
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK |