C0037 DTC: Left Front Wheel Speed Sensor Circuit Low
What Does C0037 Mean?
Diagnostic Trouble Code (DTC) C0037 indicates that the ABS module has detected a voltage or signal level below the expected range from the left front wheel speed sensor circuit. This usually points to a short to ground, excessive circuit resistance, damaged wiring, or a faulty wheel speed sensor.
Symptoms
- ABS warning light ON
- Traction Control (TCS) warning light
- Electronic Stability Control (ESC) warning
- ABS disabled during hard braking
- Traction Control may not function
- Cruise control may be disabled on some vehicles
- Additional ABS-related DTCs may be stored
Common Causes
- Faulty left front wheel speed sensor
- Sensor circuit shorted to ground
- Damaged or broken wiring harness
- Loose, corroded, or water-damaged connector
- Damaged tone ring (reluctor ring)
- Wheel bearing damage causing an incorrect air gap
- Faulty ABS control module (rare)
Typical Diagnostic Flow
How to Diagnose C0037
- Read ABS fault codes with a professional scan tool.
- Monitor live wheel speed data while driving.
- Compare the left front wheel speed with the remaining wheels.
- Inspect the sensor wiring for damage or contact with ground.
- Check the electrical connector for corrosion or moisture.
- Inspect the tone ring for cracks or missing teeth.
- Measure the sensor resistance and supply voltage according to manufacturer specifications.
Typical Values
- All wheel speed sensors should report nearly identical vehicle speeds.
- A low or missing signal usually indicates a sensor or circuit problem.
- Exact specifications vary by vehicle manufacturer.
Estimated Repair Cost
- Wheel speed sensor replacement: $70–250
- Wiring repair: $50–200
- Connector replacement: $30–120
- Tone ring replacement: $80–300
- Wheel bearing replacement: $150–500
- ABS module replacement: $400–1,200
Related DTCs
- C0035
- C0036
- C0038
- C0040
- C0050
Frequently Asked Questions
Can I drive with C0037?
Yes, but the ABS, Traction Control, and Stability Control systems may be disabled. Standard braking remains available, but braking performance on slippery roads may be reduced.
What is the most common cause of C0037?
The most common causes are a faulty left front wheel speed sensor, wiring shorted to ground, damaged connectors, or a defective tone ring.
Will clearing the DTC permanently fix C0037?
No. If the low-voltage or low-signal condition still exists, the ABS module will detect the fault again and store the DTC after the next self-test.