C1091: Speed Wheel Sensor All Coherency Failure
MediumChassisWheel Speed Sensors
What does C1091 mean?
C1091 is a diagnostic trouble code indicating "Speed Wheel Sensor All Coherency Failure". A sensor in the wheel speed sensors is reporting abnormal data or has lost communication with the ECU. Sensors can fail due to age, contamination, heat exposure, or wiring issues.
Common causes
- Faulty wheel speed sensors component
- Wiring or connector issue in the related circuit
- Failed sensor providing incorrect readings
- Software/calibration issue requiring ECU update
- Related component causing secondary fault
What should you do?
Schedule a diagnostic appointment at your earliest convenience. The vehicle is generally safe to drive short distances, but the underlying issue should be addressed to prevent it from worsening.
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Code C1091 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.