Diagnostic Trouble Code U18A4

[HansHammermill]

Does anyone happen to know what Diagnostic Trouble Code U18A4 is? I can't seem to find any information on it.

We purchased a new BoltEV and within the first month this code triggered the check engine light which cleared on its own; no associated symptoms. OnStar had no recommendations.

Also what is the best place to obtain the BoltEV Service Manual for non-commercial purposes (in order to look up codes like this). I'm also new to GM (I'm not certain what the channels are for getting technical information).

Thank you in advance for any pointers anyone has.

PS: I'm new to the forum; if I am not following the ettiqutte please let me know.

 

[cranial1963]

I got the same code within 1st two weeks of ownership, and it cleared up on its own like yours.
I took it to dealer, they ran diagnostics, they found no issues, installed some software updates and it has not happened again.
Here is description of U18A4 from dealer print out:
"Lost Communication With Hybrid/EV Battery DC Charging Communications Gateway Module On High Voltage Energy Management CAN Bus"

 

[HansHammermill]

Thank you cranial1963