U0303
Software Incompatibility with Transfer Case Control Module
A control module has detected that its software/calibration is incompatible with the transfer case control module. AWD/4WD modes may not work correctly until matching software is flashed.
A control module has detected that its software/calibration is incompatible with the transfer case control module. AWD/4WD modes may not work correctly until matching software is flashed.
Common causes
- high
Software/calibration mismatch with transfer case
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-880
- medium
Used transfer case module from different vehicle fitted
A plausible cause — test and verify before replacing parts.
Typical part cost: $90-880
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does U0303 mean?
U0303 means "Software Incompatibility with Transfer Case Control Module". It is a generic OBD-II code that points to a fault in the network / communication.
What are the most common causes of U0303?
software/calibration mismatch with transfer case; used transfer case module from different vehicle fitted; gateway module routing can messages incorrectly — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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