Originally Posted by
CL770
Hi
The "PCM Coding Incorrect" may be related to the engine tune. If the wrong flash file version was loaded it may not be fully compatible with the existing SCN coding in the ECU. This would generate that error. Ask your mechanic friend to check the file version loaded in the ecu and report back. I can look it up to see if it's correct or not.
Thinking about it a bit more..... That error is probably OK! If the the ECU has been tuned and the SCN coding has also been changed from the standard coding (eg. EGR, Air Pump, Rear 02 OFF) then the new non-standard coding can also generate this error. However, that type of error won't cause an engine light.
One other possibility is that the fuel trims are adapting to the new tune and this has temporarily generated the light. If the light doesn't come on again then everything is OK! If it stays on then look at the long term fuel trims to see if they're within limits.