C0099
4WD/AWD Rear Differential Unit Actuator A Position Sensor A
C0099 is an OBD-II diagnostic trouble code meaning: 4WD/AWD Rear Differential Unit Actuator A Position Sensor A. Common causes: actuator position sensor malfunction, open or shorted wiring harness. Estimated repair cost: $56–167.
Symptoms
- Check Engine light comes on
- Incorrect operation of the all-wheel drive system
- The vehicle enters rear-wheel drive (RWD) mode.
- Reduced dynamics and controllability
Causes
- Actuator position sensor malfunction
- Open or shorted wiring harness
- Problems with the rear differential actuator
- Corroded or damaged contacts
- Software error in the control unit
How to Fix
- Check the condition of the wiring harness and contacts
- Test the actuator position sensor
- Check the operation of the rear differential actuator
- Replace a faulty sensor or actuator
- Update control unit software
Related codes
Error C0099 by Vehicle Brand
FAQ
What does the C0099 code mean?
C0099 is an OBD-II diagnostic trouble code that indicates: 4WD/AWD Rear Differential Unit Actuator A Position Sensor A
What causes a C0099 error code?
The most common causes of C0099 include: Actuator position sensor malfunction; Open or shorted wiring harness; Problems with the rear differential actuator; Corroded or damaged contacts.
How do I fix a C0099 diagnostic trouble code?
To fix C0099: Check the condition of the wiring harness and contacts. Test the actuator position sensor. Check the operation of the rear differential actuator. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with C0099?
Limited driving only, diagnose soon
How much does it cost to fix C0099?
The estimated repair cost for C0099 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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