[RoadDogg]

This past weekend while driving in Mountain Mode up a 7.5% grade, my 2012 Volt threw some codes and I got the dreaded "Service High Voltage Charging System" warning on my dash. I've mostly been trouble free with my car for the initial 75,000 miles, with the exception of a few minor issues that were resolved easily. I stayed in mountain mode until I reached my destination. When I went back to normal mode I had about 15 miles of range left in my battery. There were no apparent issues with the car, except for the CEL and dash warning.

When I got back home on Monday, I read the following codes: P0AA6, P1E00, P1FFF. My local dealership wouldn't schedule an appointment until next Monday. The car runs fine in CS mode, but will not take a charge.

Any ideas what could be going on?

Is it safe to assume I can continue driving the car based on these fault codes? I have a 300 mile round trip planned this weekend.

 

[CCIE]

It's fine to drive, as long as you've verified that none of the coolant tanks is actually low. Suggest you order WOTs battery coolant sensor now so that you can change it out after the dealer fixes the issue.

See the first couple stickys in this sub-forum:

http://gm-volt.com/forum/forumdisplay.php?27-Problems-Issues-Driver-Warnings-or-DTCs-Chevy-Volt

This issue seems to be popping up more and more. Crazy that GM hasn't at least created a more reliable sensor. And the half-assed wiring they did as part of the recall on the early cars should have a warranty extension.

 

[terrym]

See the post I made just before your post on this very issue. I had the same problem with my 2012 recently. This seems to be a very flaky issue with the Gen 1s. WOT developed a battery coolant reservoir replacement sensor that is actually a defeat plug in that it mimics the electrical characteristics of a properly operating sensor when the coolant level is proper. The down side is that it always presents those characteristics so that if the coolant is somehow lost it will still say everything is OK to the HPCM2 module. My understanding is that this is OK because other things will prevent any damage from occurring. See WOT's posts about this as a sticky post at the top on Gen 1 stuff. I had the problem even though I have WOT's substitute in place. It is all pretty strange and there appears to be a lot of unknows.

 

[RoadDogg]

I've been reading about WOT coolant sensor for several months and have had my fingers crossed thinking I wouldn't need to do that, but maybe it's time. Thanks for the feedback!

 

[SirSpammenot]

My Volt is in the shop right now, and it had a somewhat similar failure mode. Sat night trouble started in conjunction with a lightning strike to the house. Finished charging after rebooting the EVSE. Sunday drove OK but with codes P1E00, P0335, P0336, and C1240. Would not charge Sunday night. Drove on CS mode Monday, still wouldn't charge at night. Cleared codes, started, stopped 3 times, got new codes: P1E00, C1240, P15B9, and P1A5E. Tuesday morning lights were dimmer than usual and car wouldn't engage drive or reverse. 7 DTC codes - and then completely dead 12V battery Tues night.

My point is you take a 300mi trip in a car throwing codes, make sure you know where the dealers are along the way. I would rent a car, but then again I feel freshly burned. : )
Good Luck!

 

[TheBlueFlash]

Fingers crossed it is just low coolant. OP did you check your coolant levels?

 

[RoadDogg]

Got my car back on Monday night and was told nothing was wrong with the vehicle except they needed to flash the computer. The service report states:

Scanned for codes, found P1E00, P0AA6 and P1FFF Stored. Found related bulletin PIC5920G and followed. Calls an update calibration to address these codes. Programmed HPCM2.SPS CB102 and BECM calibration SPS CD891.

This is good new, but as my extended warranty is coming to an end in about a year, I'm concerned that driving up to the mountains again could result in the same codes being thrown. Is there any indication what caused these codes in the first place? It would be a waste of money if I will need to pay $170 to have my computer reset after a weekend trip to the mountains.

 

[CCIE]

Got my car back on Monday night and was told nothing was wrong with the vehicle except they needed to flash the computer. The service report states:

Scanned for codes, found P1E00, P0AA6 and P1FFF Stored. Found related bulletin PIC5920G and followed. Calls an update calibration to address these codes. Programmed HPCM2.SPS CB102 and BECM calibration SPS CD891.

This is good new, but as my extended warranty is coming to an end in about a year, I'm concerned that driving up to the mountains again could result in the same codes being thrown. Is there any indication what caused these codes in the first place? It would be a waste of money if I will need to pay $170 to have my computer reset after a weekend trip to the mountains.

Their caused by the battery coolant level sensor going bad. Unfortunately, it often fails intermittently. So, it failed long enough to set those codes. But, it was working after the dealer cleared the codes by reprogramming the HPCM2 computer. It'll likely fail again and set those codes. I suggest either replacing the sensor with a new one. Or, better, replacing it with a WOT sensor.

 

[SmjVolt]

Can people see my posts, why don't I get responses... I NEED HELP, this is the 3rd thread that I've tried to get a response to my NEED to charge my electric car. I thought I'd have an electric car but for WAY too long I have been driving a Gas powered Volt. Even the name says electric. I absolutely love my car and have had a few of them, but what is going on, i read and read through peoples woas but I'm not seeing that much help. My dealer will not help, they plug in thik they have it, don't really listen to me, and well I just end up keeping my car with the problem.

 

[CCIE]

Can people see my posts, why don't I get responses... I NEED HELP, this is the 3rd thread that I've tried to get a response to my NEED to charge my electric car. I thought I'd have an electric car but for WAY too long I have been driving a Gas powered Volt. Even the name says electric. I absolutely love my car and have had a few of them, but what is going on, i read and read through peoples woas but I'm not seeing that much help. My dealer will not help, they plug in thik they have it, don't really listen to me, and well I just end up keeping my car with the problem.

You've been posting threads since May saying you can't charge. If the local dealer won't/can't help, it's time to find a new dealer.

 

[ilusnforc]

I also have a 2012, just over 73,000 miles. A few weeks ago I noticed the battery didn't charge after being plugged in overnight and the check engine light was on. I tried plugging in elsewhere and it did start charging. I stopped at AutoZone, they found two instances of P1E00 but didn't know what it means. I stopped at the dealership the next morning (Monday) and they said their Volt tech wouldn't have time to look at it until Wednesday. Later that afternoon the check engine light was gone. I stopped in Wednesday morning anyway and they made it sound like they weren't going to find any problems and would end up charging me to look at it so I declined. They told me to bring it back if it happens again and leave the car on so they can have the tech check it immediately.

The check engine light and a "Service high voltage charging system" message came up a few days ago so the next morning I took it back to the dealer and left the car on while they sent it back to the tech. After an hour they said they have to reprogram something and it would take 45 minutes and is covered under warranty.

The receipt says:
Found DTC P0AA6 check circuits, checked ok, found PIC5920G.
Reprogram the HPCM2 and the BECM per PIC5920G. Codes CBD90 and CD51E

Anyone have any idea what the service bulletin PIC5920G is? Nothing really coming up in a google search.
Also, what do the codes mean? P1E00, P0AA6, CBD90, CD51E

Glad to have it back and working again but concerned what it might cost to deal with these kind of issues after warranty.

Also, I'm not sure that they were finished working on it. On my way home I heard something rolling around in the back. I looked in the rear hatch and found the floor cover not closed all the way so I looked under it and found a drill and some pry tool that the tech left there.

 

[Steverino]

Anyone have any idea what the service bulletin PIC5920G is? Nothing really coming up in a google search.

When I google PIC5920 I find:
Volt and ELR
• 2011-2014 Chevrolet Volt and 2014 Cadillac ELR – #PIC5920: Vehicle Will Not Charge And Hybrid Loss Of Isolation With DTC P0AA6
Note:
2011-2014 Chevrolet Volt and 2014 Cadillac ELR — the HPCM2 and BECM must Be updated with the latest calibrations available on TIS2WEB prior to proceeding with OnStar® cellular communication upgrade. Use the unique labor operation in the
#PIC5920.

 

[SmjVolt]

Thank you for the reply CCIE, but unfortunately that does not help me. Again I sit with my car plugged in and no green light, an orange light yes but that doesn't help me either. I have been posting for a long time with no response from anyone on this thread or many others thanks for actually seeing that. As for the dealer, that is precisely why I keep trying on here...MORRIS Minnesota is not really the mecca for anything besides huge farm trucks (go merrrica, as spit hits the tin can). I have been left with not much of a choice but to try and diagnose myself as I'm not keen on spending just under 200 every time they "clear/reset my computer." SO HEEEEELLLLPPP, has anyone actually figured out anything when it is charging one day maybe two then off for like a week. Oh and I also keep posting to try and grab the ear of a GM person on here, because God knows when you call in there (due to elimanation of the Volt team) you get questions like "have you put gas in your GM" or "so this is an electric car?" HELP

 

[CCIE]

Thank you for the reply CCIE, but unfortunately that does not help me. Again I sit with my car plugged in and no green light, an orange light yes but that doesn't help me either. I have been posting for a long time with no response from anyone on this thread or many others thanks for actually seeing that. As for the dealer, that is precisely why I keep trying on here...MORRIS Minnesota is not really the mecca for anything besides huge farm trucks (go merrrica, as spit hits the tin can). I have been left with not much of a choice but to try and diagnose myself as I'm not keen on spending just under 200 every time they "clear/reset my computer." SO HEEEEELLLLPPP, has anyone actually figured out anything when it is charging one day maybe two then off for like a week. Oh and I also keep posting to try and grab the ear of a GM person on here, because God knows when you call in there (due to elimanation of the Volt team) you get questions like "have you put gas in your GM" or "so this is an electric car?" HELP

You can try starting your own thread, clearly describing what you're seeing, and the codes the computer is showing. You'll need a basic OBD2 scanner to pull those codes.


We may able to help you fix it yourself. But, it sounds like you may need to bring it to a dealer who can properly troubleshoot. GM doesn't really listen or help here much anymore. Sometimes a GM marketing person chimes in, but it's rare these days.

 

[SmjVolt]

No charge

Thank you for your response, I will check and read more around to see what I can find out. I have started threads but have got no responses and have also placed my codes that I have read on those threads which is why I came to other areas to just to and get a response. I was hoping people had a consistent similar problem that they have figured out without just placing their car in a dealer to see in a month or so only to have it "repaired" incorrectly. I'm hoping it is something with the 12v as I'm reading things about that as well, any thoughts? I charged the 12v and tried to charge the car right after and it did the same things, orange, maybe green walk away then no lights at all, try again and again...nothing.

 

[CCIE]

Thank you for your response, I will check and read more around to see what I can find out. I have started threads but have got no responses and have also placed my codes that I have read on those threads which is why I came to other areas to just to and get a response. I was hoping people had a consistent similar problem that they have figured out without just placing their car in a dealer to see in a month or so only to have it "repaired" incorrectly. I'm hoping it is something with the 12v as I'm reading things about that as well, any thoughts? I charged the 12v and tried to charge the car right after and it did the same things, orange, maybe green walk away then no lights at all, try again and again...nothing.

I read the posts you've made in the last few months. They're somewhat confusing and don't have the detail we'd need to provide much help. Without a current list of DTCs that an OBD2 scanner is seeing, the color and action of the charging indicator light doesn't mean much.


It's possible your 12V battery is bad. Test it with a multimeter and see what voltage you get with the car off.


Have you tried charging from a different EVSE? Maybe a local public one? Trying to rule out an issue with your EVSE or home power.


What did the dealer say when they looked at it? A pic of the service invoice showing what they found & did may be helpful.

Finally, you may get a better response if you start a new thread instead of posting in other unrelated threads. Including the info I asked about would be a good start for that new thread.

 

[SmjVolt]

Let me know if you see my new thread as I do not. Thanks for all your guidance on this, I know it is just something little I just know it. I hate sitting somewhere and not charging.