C0040: Right Front Wheel Speed Sensor Circuit Malfunction
Can you still drive? Yes, but ABS and traction control are disabled for this wheel. Use extra caution when braking on wet or icy roads.
What Does C0040 Mean?
Code C0040 indicates a fault in the right front wheel speed sensor circuit as detected by the ABS module. This sensor provides critical speed data for ABS, traction control, and electronic stability control. The code is set when the sensor signal is missing, erratic, or outside the expected range.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Failed right front wheel speed sensor
- Damaged or corroded sensor wiring
- Cracked or damaged tone ring
- Metallic debris on sensor tip
- Wheel bearing failure affecting sensor gap
Symptoms
- ABS warning light on
- Traction control disabled
- Stability control light on
- ABS not engaging during hard braking
- Cruise control may not function
Diagnostic Steps
- 1Scan ABS module for codes and freeze frame data
- 2Visually inspect the right front wheel speed sensor and wiring
- 3Clean any metallic debris from the sensor tip
- 4Measure sensor resistance and compare to specification
- 5Inspect tone ring through the wheel hub for damage
- 6Compare live data from all four wheel speed sensors during a road test
Recommended Parts & Tools
wheel speed sensor
sensor wiring repair harness
brake cleaner
wheel bearing assembly
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $50 - $400 |
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Frequently Asked Questions
Can debris on the sensor cause C0040?
Yes, metallic brake dust and debris can accumulate on the magnetic sensor tip and interfere with the signal. Cleaning the sensor can sometimes resolve the code.
Does C0040 affect my cruise control?
On many vehicles, yes. The cruise control system requires valid wheel speed signals to operate, so it may be disabled when an ABS sensor code is present.
Community Fix Reports
Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.
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