Ford C1168: Rear Right Wheel Speed Sensor Coherence Fault
Diagnostic trouble code C1168 indicates a coherence fault in the rear right wheel speed sensor circuit. This Ford-specific code is triggered when the ABS control module detects that the signal from the rear right wheel speed sensor does not match the readings from the other wheels or is logically inconsistent with vehicle speed. The sensor may produce erratic, intermittent, or out-of-range signals, compromising the ABS system's ability to accurately monitor wheel speed.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or worn rear right wheel speed sensor
- Damaged, dirty, or missing teeth on the rear right tone ring (exciter ring)
- Corroded, shorted, or open wiring or connector in the sensor circuit
- Incorrect air gap between the sensor and tone ring
- Faulty ABS control module
- Tire diameter mismatch between axles
3. Symptoms You Will Notice
- ABS warning light illuminated on the dashboard
- ABS system may disable or function erratically
4. Step-by-Step Diagnosis
Scan for additional ABS codes and freeze frame data
Visually inspect the rear right wheel speed sensor, tone ring, and wiring for damage or contamination
Measure sensor resistance and AC voltage output while spinning the wheel
Check air gap between sensor and tone ring with a feeler gauge
Compare tire sizes and pressures across all wheels
If all else passes, test the ABS module per manufacturer procedures
5. Frequently Asked Questions
Is it safe to drive?▼
Driving is possible but not recommended. The ABS system may be disabled, increasing the risk of wheel lockup during hard braking, especially on slippery surfaces. Have the issue diagnosed promptly.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the sensor, tone ring, or wiring needs replacement. Labor adds $80–$150 per hour.