What it means
The driveline control module monitors data from rear differential actuator B and sets this code when the data is invalid or outside the expected range.
How it works
Rear differential actuator B is part of the system that controls how the rear differential operates in 4WD or AWD. The driveline control module checks the data reported by this actuator and sets C0098 when that data is invalid or outside the expected range.
Common causes
Most likely first.
- Actuator data or calibration fault
- Damaged wiring or connector
- Power or ground fault
- Driveline control module fault
Symptoms
- AWD or 4WD warning
- AWD may be unavailable or limited
How to diagnose it
- Use a scan tool to read the driveline module’s freeze-frame and live data for actuator B, noting when the reported data becomes invalid.
- Check the rear differential actuator B connector and nearby harness for looseness, corrosion, moisture, chafing, or impact damage.
- Compare actuator B data with commanded operation and other available driveline data to see whether the fault is constant or occurs during a particular mode change.
- Check actuator B power and ground under the conditions in which the fault occurs, following the vehicle’s wiring information.
- Test the actuator B signal wiring for opens, shorts, or poor connections, then assess actuator calibration and operation using the manufacturer’s procedure.
- If wiring, power, ground, and actuator operation check out, investigate the driveline control module and its communication connections.
Common fixes
- Clean and secure the actuator B connector and repair damaged nearby wiring.
- Repair an open, short, or poor ground in actuator B’s circuit.
- Correct an actuator B calibration issue using the manufacturer’s procedure.
- Replace rear differential actuator B if its data remains invalid after circuit checks.
- Repair or replace the driveline control module if its power, ground, wiring, and actuator inputs are verified.
Can I keep driving?
AWD or 4WD may be limited or unavailable, so avoid relying on it for slippery roads or demanding terrain. If the vehicle drives normally in two-wheel drive, limit driving to suitable conditions and have the fault diagnosed.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.