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Service Indicator Comes On Early?

19K views 17 replies 11 participants last post by  XJ12 
I had one when trying to shift from PARK and my HVAC GUI controls stopped toggling and indicating. I'm guessing something HVAC related (either cabin or traction battery cooling related) didn't report status correctly and the car wouldn't let me drive. HVAC GUI controls were not working, but the manual controls appeared to be as I still could change fan speeds and felt heat.
 
Yes - my Service Engine Soon light has come on twice now, the first time after about 30 days (April 2017) at 1,800 miles and then again
on 10/23/17 at 10,700 miles. Both times there were no known visible issues, the car ran fine and all the controls
were functional.

Both times I dropped the car off at the dealer, they ran diagnostics, updated and/or reprogrammed the HPCM2 (Hybrid/EV Powertrain Control Module 2),
whatever all that means, and I was back on the road.

Codes:
1st time: U18A4 - Lost communication with Hybrid/EV Battery DC Charging Communications Gateway Module
2nd time: P3021 - Hybrid/EV Battery DC Charging Negative Voltage Sensor Stuck Low

Hopefully this is the worst I'll experience...
Thanks for adding your personal experience to the forum/knowledge base.

So after the service light went away and "the car ran fine and all the controls were functional", how long from then to your service dept visit? I have a service dept visit scheduled a week from now and am worried the error codes will go away. When your Bolt returned to normal, did the service light go away as well?
 
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