C0068 DTC: Right Front Wheel Speed Sensor Circuit Low Frequency
What Does C0068 Mean?
Diagnostic Trouble Code (DTC) C0068 indicates that the ABS control module has detected a lower-than-expected signal frequency from the right front wheel speed sensor. This means the sensor is generating fewer signal pulses than expected for the current wheel speed. The condition is commonly caused by a faulty wheel speed sensor, a damaged tone ring, excessive sensor air gap, wheel bearing wear, or wiring problems. An inaccurate wheel speed signal can reduce the performance of the Anti-lock Braking System (ABS), Traction Control System (TCS), and Electronic Stability Control (ESC).
Symptoms
- ABS warning light illuminated.
- Traction Control (TCS) warning light ON.
- Electronic Stability Control (ESC) warning.
- ABS intervention at low speeds.
- Traction Control disabled.
- Incorrect right front wheel speed displayed in live data.
- Cruise control may stop operating on some vehicles.
- Additional ABS DTCs stored.
Common Causes
- Faulty right front wheel speed sensor.
- Damaged or cracked tone ring.
- Excessive sensor-to-tone ring air gap.
- Metal debris attached to the magnetic sensor.
- Wheel bearing wear causing sensor misalignment.
- Damaged wiring harness.
- Loose or corroded electrical connector.
- Faulty ABS control module (rare).
Typical Diagnostic Flow
How to Diagnose C0068
- Read ABS DTCs using a professional scan tool.
- Monitor live wheel speed data while driving.
- Compare the right front wheel speed with the remaining wheels.
- Inspect the tone ring for cracks, missing teeth, or excessive rust.
- Measure the sensor air gap according to manufacturer specifications.
- Inspect the wiring harness and connector for damage.
- Check the wheel bearing for excessive play.
- Clean the magnetic sensor if metal particles are present.
Typical Values
- Wheel speed values should closely match the other wheels.
- Signal frequency should increase smoothly as vehicle speed increases.
- A lower-than-normal frequency indicates an abnormal sensor or tone ring signal.
- Actual specifications vary by vehicle manufacturer.
Common Repair Mistakes
- Replacing the wheel speed sensor without inspecting the tone ring.
- Ignoring wheel bearing wear that changes the sensor air gap.
- Failing to clean metal debris from the magnetic sensor.
- Repairing wiring without checking connector terminal tension.
- Clearing the DTC before verifying the repair with a road test.
- Skipping live data comparison between all four wheel speed sensors.
Recommended Diagnostic Tools
- Autel MaxiSYS Series
- Launch X431 Series
- Bosch KTS
- Snap-on Zeus
- Thinktool Series
- Digital Multimeter (DMM)
- Automotive Oscilloscope for waveform analysis
Using a professional scan tool together with a digital multimeter and an oscilloscope allows technicians to verify sensor output, inspect waveform quality, and accurately identify wiring or component faults.
Estimated Repair Cost
- Wheel speed sensor replacement: $70–250
- Tone ring replacement: $80–300
- Wheel bearing replacement: $150–500
- Wiring repair: $50–200
- Connector replacement: $30–120
- ABS control module replacement: $400–1,200
Related DTCs
- C0065
- C0066
- C0067
- C0069
- C0070
Frequently Asked Questions
Can I drive with C0068?
Yes. Normal braking remains available, but the ABS, Traction Control, and Stability Control systems may be disabled or operate improperly until the fault is repaired.
What is the most common cause of C0068?
The most common causes are a faulty right front wheel speed sensor, damaged tone ring, excessive sensor air gap, worn wheel bearing, or damaged wiring.
Will clearing the DTC permanently fix C0068?
No. Clearing the code only removes it temporarily. If the underlying problem has not been repaired, the ABS control module will detect the fault again during the next drive cycle.