Code result
U0301
Software Incompatibility with ECM/PCM
Moderate severity
What it means
A control module has detected that its software/calibration is incompatible with the engine ECM/PCM. Typically appears after a partial flash, mismatched coding, or fitting a used ECM from a different vehicle.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Software/calibration mismatch with ECM
highOne of the most commonly reported causes for this code — check this first.
Used ECM from different vehicle fitted
mediumA plausible cause — test and verify before replacing parts.
Gateway module routing CAN messages incorrectly
lowLess common, but worth ruling out after the more likely causes.
Related help
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