Check engine light on

[WopOnTour]

Rusty,
You make me feel guilty. It's just I hate to have them mess with it. But guess it can't stay new forever.
This is sure great forum. To be able to get info quickly from guys like you.
Les

The reality is the battery swaps out from under the car with nary an indication.So assuming that i what they decide to so, it' pretty uninstrusive.
My intention was to inform you that your DTC is indicating a fault that shouldnt result in a seriou isue that would "strand" you somewhere on the road, or result in any serious collateral damage to any of the Volt's systems.
But you should get it into your dealer as soon as convenient.
HTH
WOT

[Lest]

More CEL data. Last Tuesday, I went to the dealer with the CEL read by onstar of POA9E (battery temperature sensor shorted). The dealer plugged in to read it and the lamp went out, and they not able to read error. They said to drive it, and if it came back, I should return. The CEL showed up again on the way home and stayed on all week. I returned today, they checked it out, said they located the defective modules and have them on order. I can come back Wednesday, at which time it will take 3 to 4 hours to install if I wished to wait.
Les

[WopOnTour]

More CEL data. Last Tuesday, I went to the dealer with the CEL read by onstar of POA9E (battery temperature sensor shorted). The dealer plugged in to read it and the lamp went out, and they not able to read error. They said to drive it, and if it came back, I should return. The CEL showed up again on the way home and stayed on all week. I returned today, they checked it out, said they located the defective modules and have them on order. I can come back Wednesday, at which time it will take 3 to 4 hours to install if I wished to wait.
Les

Did they say whether they were swapping out the entire battery pack? or just replacing the Battery Interface Control Module (BICM) itself? The reason I ask is this points to the root cause of this fault.(i.e. temperature sensor itself, vs. input monitoring equipment/controller)
Let us know what happens Wednesday!
WOT

[Lest]

WOT & Rusty,
All is well. They did swap out the battery and updated the software. I got to participate in the software updates. It was interesting to see that huge battery there and the special fixture and jack to install it. From pictures you don't realize how really big it is. No more CEL for now.

[Stilgar99]

WOT & Rusty,
All is well. They did swap out the battery and updated the software. I got to participate in the software updates. It was interesting to see that huge battery there and the special fixture and jack to install it. From pictures you don't realize how really big it is. No more CEL for now.

Great! glad it all worked out.

Stilgar

[Frankman]

My check engine light (CEL) just turned on today. OnStar ran a diagnositcs report and said that there is a problem with the propulsion system and that I should take it in for servicing within one day. So tomorrow I will be at my dealer with my Volt that has been running perfectly up until now. Actually it still is running fine with the CEL on.

[WopOnTour]

My check engine light (CEL) just turned on today. OnStar ran a diagnositcs report and said that there is a problem with the propulsion system and that I should take it in for servicing within one day. So tomorrow I will be at my dealer with my Volt that has been running perfectly up until now. Actually it still is running fine with the CEL on.

So they didn't give you an actual DTC then? The Onstar folks are pretty much being trained to say "there's a problem with your propulsion system" whenever a fault is detected. (and recommend a dealer visit)
With certain DTCs that have set on the early Volts it might only be as a "reprogramming" to alleviate the issue.
So knowing the actual DTCs present would help us, to help you, as far previous experience documented here in the forums.
Or you could just take it to your dealer and get them to look after it ASAP
WOT

[Frankman]

So they didn't give you an actual DTC then? The Onstar folks are pretty much being trained to say "there's a problem with your propulsion system" whenever a fault is detected. (and recommend a dealer visit)
With certain DTCs that have set on the early Volts it might only be as a "reprogramming" to alleviate the issue.
So knowing the actual DTCs present would help us, to help you, as far previous experience documented here in the forums.
Or you could just take it to your dealer and get them to look after it ASAP
WOT

Thanks. In the future I will ask the OnStar person what the DTC is. Tomorrow morning I will find out what the problem is and will report back.

[Frankman]

After 4 hours at the Chevy dealer today they could not figure out why the Check Engine Light (CEL) Is ON. It was frustrating to me because the "certified" Volt service technician told me that all he could do is extract the data from the car onto a PC, and upload it GM and then wait. He said that he then must wait for a "Volt Engineer" to come to the dealership to determine what the problem is. The service manager told me that there are only 2 regional Volt engineers covering Southern California so he didn't know when he would get there. The service writer wanted me to leave the car there indefinitely until they could figure it out but I opted to take the car home after the technician extracted the data from the vehicle onto his PC. The service manager will call me when the Volt Engineer can be there.

The technician told me that when talking on the phone with GM they thought the fault had something to do with the heating system. When I got into the car to leave the heat was set to 88 degrees and I noticed that while the vehicle was stationary in the service bay it used up 10 percent of the battery charge (via iPhone app while bored in the waiting area). Here are the DTCs that they gave me so if anyone knows what they are please let me know. By the way, when I left the dealer the CEL was OFF.

P1AFO
P1AFZ
P1EZZ
P0AC4
U0121
U0254

[WopOnTour]

@Frankman
Hmmm well I think that all your Z's are probably 2s (the DTC are in hexideximal code so "F" is the highest letter used)
and I dont really like what I see if they are in fact "2"s (Loss Of Isolation DTCs?)

But I will be AFK over the next day or so but will look into these DTCs once I return but in the meantime if you wouldnt mind double-checking your documentation and confirm that:
P1AFZ isnt actually P1AF2
and
P1EZZ isnt actually P1E22

Thanks
WOT