2015 Impala CNG down.

[Wike R]

While driving CNG went into unavailable mode. No codes or CEL, car had a half tank of fuel left. Will start on CNG and after 10 seconds goes back to unavailable mode. AnybodVehicy else have the same symptoms and what was the diagnosis and outcome. Vehicle has only 20k and has worked flawlessly, has anyone experienced a HP reg failure without any codes.

Thanks!

[Wike R]

Anyone with more info on auto initiated switch to gasoline mode, duration ect. Supplement only has one paragraph of info.

[Wike R]

Should of made it a rhetorical question. If you run the vehicle on CNG too long it will switch over to mogas automaticaly, one hour on the highway and it was back on CNG.

[cnguser]

I have observed on my 2015 Impala that once it a while it will switch from gas to CNG for a few miles, probably just to "exercise" that system.
(My fueler is down awaiting a new compression module, so I run the car on gas, saving the CNG supply as back up).

[Wike R]

Are you still on the orginal HPR, and thanks for adding to the discussion.

[cnguser]

I tried to answer previously, but not sure it went through.
The car has the original HPR, no problems noted.