What are the common causes of U0301?

Software in the ECM/PCM that does not match the rest of the vehicle. The ECM/PCM replaced without programming to the vehicle. Corrupted or outdated calibration in the ECM/PCM. A module programming step that did not complete.

Read stored codes on every module and note the mismatched part numbers. Record the software and calibration part numbers in the ECM/PCM. Reprogram the ECM/PCM with the latest calibration for the vehicle. Check for a service bulletin that covers the ECM/PCM software. Replace the ECM/PCM if programming will not complete. Clear the code and retest.

U0301

Software Incompatibility With ECM/PCM

System: Network communication (U code)
Lamp: Check Engine Light
Category: Network Communications

What it means

U0301 means Software Incompatibility With ECM/PCM.

Check these first

Software in the ECM/PCM that does not match the rest of the vehicle
The ECM/PCM replaced without programming to the vehicle
Corrupted or outdated calibration in the ECM/PCM
A module programming step that did not complete

What to do next

Read stored codes on every module and note the mismatched part numbers
Record the software and calibration part numbers in the ECM/PCM
Reprogram the ECM/PCM with the latest calibration for the vehicle
Check for a service bulletin that covers the ECM/PCM software
Replace the ECM/PCM if programming will not complete
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.