C0049 DTC: Right Rear Wheel Speed Sensor Circuit Intermittent/Erratic
What Does C0049 Mean?
Diagnostic Trouble Code (DTC) C0049 indicates that the ABS control module has detected an intermittent or erratic signal from the right rear wheel speed sensor circuit. The signal may be unstable, drop out intermittently, or differ significantly from the signals received from the other wheel speed sensors, reducing the effectiveness of the ABS, Traction Control (TCS), and Electronic Stability Control (ESC) systems.
Symptoms
- ABS warning light illuminated
- Traction Control (TCS) warning light ON
- Electronic Stability Control (ESC) warning
- Unexpected ABS activation during braking
- Traction Control disabled
- Cruise control may stop working on some vehicles
- Intermittent ABS operation
- Additional ABS-related DTCs stored
Common Causes
- Faulty right rear wheel speed sensor
- Intermittent wiring connection
- Loose, corroded, or water-damaged connector
- Broken or damaged wiring harness
- Cracked or rusty tone ring (reluctor ring)
- Wheel bearing wear causing excessive sensor air gap
- Metal debris attached to a magnetic wheel speed sensor
- Faulty ABS control module (rare)
Typical Diagnostic Flow
How to Diagnose C0049
- Read ABS DTCs with a professional scan tool.
- Monitor live wheel speed data while driving.
- Compare the right rear wheel speed with the other wheels.
- Move the wiring harness while observing live data to locate intermittent faults.
- Inspect the connector for corrosion, moisture, or loose terminals.
- Check the tone ring for cracks, missing teeth, or heavy rust.
- Inspect the wheel bearing for excessive play.
Typical Values
- All four wheel speed sensors should display similar wheel speeds during normal driving.
- Signal dropouts or unstable readings indicate an intermittent sensor or wiring fault.
- 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
- C0046
- C0047
- C0048
- C0050
- C0051
Frequently Asked Questions
Can I drive with C0049?
Yes. Normal braking remains available, but the ABS, Traction Control, and Stability Control systems may not function correctly until the fault is repaired.
What is the most common cause of C0049?
The most common causes are an intermittent wheel speed sensor, damaged wiring, loose connectors, a cracked tone ring, excessive wheel bearing play, or metal debris on the sensor.
Will clearing the DTC permanently fix C0049?
No. Clearing the code only removes it temporarily. If the intermittent signal fault remains, the ABS module will detect it again during the next drive cycle.