C0398 on 2012-2016 Chevrolet Tahoe: Service 4WD Light Causes and Fixes
This code indicates a problem with the transfer case position sensors. Often, the fix is to reprogram the Transfer Case Control Module (TCCM), which a dealer or equipped independent shop must do. If that doesn't work, the transfer case encoder motor (actuator), which houses the sensors, is the next most likely part to fail. Wiring issues are also a possibility.
Most Likely Cause
Transfer Case Control Module (TCCM) Software/Calibration Issue
Est. Time
1.8 hrs
DIY Doable?
🔧 Shop
Parts Price
$30 – $400
Drivable, but...
— Yes, but your 4WD system will be disabled and may be stuck in one mode (often 4HI). [Bulletin #GCUS-3-804] Driving a vehicle locked in 4HI on dry pavement can cause tire scrubbing, a feeling of lost power, and potential damage to the drivetrain over time. In some cases, the transfer case can become stuck in Neutral, which would prevent the vehicle from moving at all. [Bulletin #PIP5217B, 7]
Key Takeaways