U0403
Invalid Data Received from Transfer Case Control Module
The Transfer Case Control Module is present on the data bus but the values it reports are implausible — out of range, frozen, or failing the checksum or rolling-count check. The receiving modules reject the data. Four-wheel-drive control becomes unreliable. Causes include a faulty sensor feeding the module, internal computation errors, a software or calibration mismatch after a repair, or bus interference corrupting the frames.
The Transfer Case Control Module is present on the data bus but the values it reports are implausible — out of range, frozen, or failing the checksum or rolling-count check. The receiving modules reject the data. Four-wheel-drive control becomes unreliable. Causes include a faulty sensor feeding the module, internal computation errors, a software or calibration mismatch after a repair, or bus interference corrupting the frames.
Common causes
- medium
Transfer case internal sensor or processing fault
A plausible cause — test and verify before replacing parts.
Typical part cost: $90-1650
- medium
CAN corruption causing checksum errors
A plausible cause — test and verify before replacing parts.
Typical part cost: $90-1650
See all causes + fix costs
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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
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Frequently asked questions
What does U0403 mean?
U0403 means "Invalid Data Received from 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 U0403?
transfer case internal sensor or processing fault; can corruption causing checksum errors; 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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