Chassis Definition only Lights the check engine lamp

C009C: 4WD/AWD Rear Differential Unit Actuator A Position Sensor Correlation

Standardized SAE J2012 code · C00xx codes

Safety-critical system. Faults in airbags, brakes, steering or high-voltage components can put people at risk. Follow the manufacturer's service information and safety procedures, or have the vehicle checked by a qualified workshop.

What does C009C mean?

Position sensors on rear differential actuator A disagree.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

  • ABS warning light on
  • ESC/stability control deactivated
  • Possible reduced brake assist
  • Speedometer may behave erratically

Common causes

  • High One sensor drifted

Likelihood is a general estimate across vehicles; your make and model may differ.

Add your car to see reports of C009C on the same make and model first.

C009C in the community

Ask about C009C

No one has posted about C009C yet

Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.

Describe your C009C problem