I have an error code 641.12 that appears on my 7530. It usually appears 5 minutes or so after startup. it doesn’t seem to affect performance and no other codes appear.
If the engine is turned off and on again the code appears even without the engine running. once the engine cools down the code is no longer present at startup.
I have checked that the turbo actuator connection appears to be free and appears to be working as it should.
ECU 000641.12 is a communication error between the ECU and the turbo actuator. Look for damaged wiring (rodents?) Or bad connections. Other than that, a VGT Reman !!
I have checked the connector of the two cables that go to the Turbo and the Actuator, they seem to be fine and do not seem to throw the code when working with them,
Strange that it seems to be related to engine temperature in some way. When the engine coolant hits 50 degrees or so, the code pops up and stays active until it cools down a bit, which seems to rule out the wiring.
If the actuator was faulty, would it still work when running and can you see it working when the ignition is turned off, which is normal I think?