CEL U0121

[Fast_AT4]

Remote start didnt work this morning and upon getting in, noted the CEL. Chatted with OnStar and they stated I dont need to be worried about it or take action...?



U0121 seems to be related to loss of communication with ABS module. Is this a "known" event and the CEL will "just go away" as OnStar seemed to lead onto...or shall I get to the dealership?

 

[Fast_AT4]

Was able to remote start this morning #ColdStartLove and no CEL. Will be chatting about the CEL upon my next oil visit or if returns.

 

[jeportera]

Was able to remote start this morning #ColdStartLove and no CEL. Will be chatting about the CEL upon my next oil visit or if returns.

Quick question, did the this CEL start after you disconnected the battery? I'm installing an amp and Stealthbox and I'm getting this code now that I have hooked everything back up.

 

[Fast_AT4]

Honestly, I do not recall the chain of events....sorry man.