Trouble Code U0002 Anyone Know What This is For?

[commonsense]

Just put a new battery in. Had trouble starting the car. Got an ESC warning light, which eventually went away. But now I have a Check Engine Light with the code U0002. Any help would be appreciated.

[turbodharma]

"OBD-II Trouble Code Description for U0002 Fiat
High Speed CAN Communication Bus Performance"


U0002 Possible Causes


Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s)


Check for more codes


Faulty Control Module


Control Module harness is open or shorted


Control Module circuit poor electrical connection


Read more: https://www.autocodes.com/u0002.html





what kind of battery did you put in? is it the same as the one you had before? thats my best guess based off of this..maybe a bad quality battery? or check the terminals are properly tightened and not wiggling?

[map]

I wonder if you erased that code, if it might not come back again.

[commonsense]

Well, I have an idea on this. When I had trouble starting it, I disconnected my 500 Madness piggyback controller and inserted the bypass plug. I've never really used it before. Perhaps it's triggering the fault code. Anyway, I will reconnect the 500 Madness controller and see if the light goes off.

[map]

I was thinking maybe it was caused by disconnecting the battery. I have no experience with it, but was thinking it might have been relearning the system. Once a code is set, some are stored. Maybe use a code scanner and remove the code, then see if it comes back? Possibly one of the elements on the bus was a bit slower coming back online, than the system expected. (I've had my battery disconnected several times with no errors, so just a guess.)

[commonsense]

Problem solved. I reset the code and reconnected the 500 Madness piggyback and no more check engine lights. I guess it was just changing the battery that caused all this.