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Yesterday the wife ran to the store and came back saying something is wrong with the car. Dash says "Service high voltage charging system" and it's not charging. First real issue in four years. (Had a thing with the infotainment last year but I don't call that 'mechanical'.) Get to the local dealer this afternoon. Error codes P0AA6 & P1FFF; these reference to technical bulletin PIC 5900J (service writer gave me a copy of the bulletin). Bulletin directs to check coolant levels and check for leaks in the battery pack. (no problems found.) Bulletin then directs to "Program the HPCM2 (K114B) and the BECM K16 with the latest calibration." Service writer says it not covered under Voltec, only under B2B (which of course is expired). I say that doesn't make sense, how is computer/software that controls the battery/charging not part of Voltec? (??!!!???) I ask to talk to Chevy customer service for clarification; he gives a look and goes to check with his boss. Comes back with the 800 number that I have to call on my phone.

Corporate isn't very helpful - gives the same response. Only the ACTUAL battery (and I guess other parts you can actually poke with your finger) are Voltec - software isn't. Which again, doesn't make sense, without the battery, et al., the car doesn't need the software. Chicken, meet egg. Chevy referred back to the dealer customer service manager. I asked to talk with him. The service writer disappeared into the back. Came back and said the manager would try to "see if somehow this could be covered under Voltec". By now I'm running short of time for another appointment, so I took the car and left. Now I'm waiting to see what happens. I'm not really expecting much satisfaction.

Last spring (04/2019) had the N172130462 PCM PROGRAMMING update performed. This had to do with cell balancing, correct? I also think this update is the one related to the 18215 recall, correct? This recall was supposedly limited to select 2013's and it seems mine was not so affected since I never got a notice and the recall doesn't show up in my chevy.com/OnStar/whatever you call it this week account records. And I never had the reduced propulsion power issue happen (wife would have really gone ballistic) which also seems to be an indicator of the recall issue. Could the current error be related to last year's update?

As I understand it, cell balancing issues can take a while to show themselves depending on driving & charging habits. Most of our driving is short range around town and seldom draining the battery all the way to zero miles. In the summer, like now, I usually make a weekly 90-ish mile round trip to meet friends for scuba diving at a local lake. The rest of the year there might be 1-2 times a month that the battery gets drained. Otherwise it's short (sub 30 mile) trips and it's always plugged in when in the garage. Most of the time it never gets much below 25-50% SOC.

Back to my main question - should this $200 reprogramming be covered by warranty? This is my first error code situation and the dealer staff don't understand Volts. This particular service writer said exactly that . At his "last store" the only time he saw a Volt was a few oil changes and one battery ("skateboard") that had got replaced because "it aged out" (a 2011). I just looked at him and didn't even try to correct him or get more detail which he obviously didn't have.

Other posts here say it should be covered.

2013 model year, currently at 78,800+ miles
 

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Yesterday the wife ran to the store and came back saying something is wrong with the car. Dash says "Service high voltage charging system" and it's not charging. First real issue in four years. (Had a thing with the infotainment last year but I don't call that 'mechanical'.) Get to the local dealer this afternoon. Error codes P0AA6 & P1FFF; these reference to technical bulletin PIC 5900J (service writer gave me a copy of the bulletin). Bulletin directs to check coolant levels and check for leaks in the battery pack. (no problems found.) Bulletin then directs to "Program the HPCM2 (K114B) and the BECM K16 with the latest calibration." Service writer says it not covered under Voltec, only under B2B (which of course is expired). I say that doesn't make sense, how is computer/software that controls the battery/charging not part of Voltec? (??!!!???) I ask to talk to Chevy customer service for clarification; he gives a look and goes to check with his boss. Comes back with the 800 number that I have to call on my phone.

Corporate isn't very helpful - gives the same response. Only the ACTUAL battery (and I guess other parts you can actually poke with your finger) are Voltec - software isn't. Which again, doesn't make sense, without the battery, et al., the car doesn't need the software. Chicken, meet egg. Chevy referred back to the dealer customer service manager. I asked to talk with him. The service writer disappeared into the back. Came back and said the manager would try to "see if somehow this could be covered under Voltec". By now I'm running short of time for another appointment, so I took the car and left. Now I'm waiting to see what happens. I'm not really expecting much satisfaction.

Last spring (04/2019) had the N172130462 PCM PROGRAMMING update performed. This had to do with cell balancing, correct? I also think this update is the one related to the 18215 recall, correct? This recall was supposedly limited to select 2013's and it seems mine was not so affected since I never got a notice and the recall doesn't show up in my chevy.com/OnStar/whatever you call it this week account records. And I never had the reduced propulsion power issue happen (wife would have really gone ballistic) which also seems to be an indicator of the recall issue. Could the current error be related to last year's update?

As I understand it, cell balancing issues can take a while to show themselves depending on driving & charging habits. Most of our driving is short range around town and seldom draining the battery all the way to zero miles. In the summer, like now, I usually make a weekly 90-ish mile round trip to meet friends for scuba diving at a local lake. The rest of the year there might be 1-2 times a month that the battery gets drained. Otherwise it's short (sub 30 mile) trips and it's always plugged in when in the garage. Most of the time it never gets much below 25-50% SOC.

Back to my main question - should this $200 reprogramming be covered by warranty? This is my first error code situation and the dealer staff don't understand Volts. This particular service writer said exactly that . At his "last store" the only time he saw a Volt was a few oil changes and one battery ("skateboard") that had got replaced because "it aged out" (a 2011). I just looked at him and didn't even try to correct him or get more detail which he obviously didn't have.

Other posts here say it should be covered.

2013 model year, currently at 78,800+ miles
simple answer Yes it is part of Voltec warranty.

I you got the full bulletin, at the bottom will be warranty code. However. You need to know if your Voltec warranty is still active by Date. You under by mileage but its an 8 year warranty from the time the car was first put into service.

I had SHVCS message a few weeks ago. Same codes as you. I was at 98,200mi and warranty end date 10/27/20. They performed the service bulletin and then did the software reprograming that changed the trigger value of the coolant level sensor. All covered under Voltec warranty.
 

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See this thread:

Service high voltage charging system error with wot plug

Post 32 though 37.

Read the NHTSA service bulletin I linked in 37.
 

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Discussion Starter #4
Thanks Dennis, that should help - I hope. Seems pretty straightforward. According to mychevy/onstar warranty tracker I still have 21K miles and 7 months left on my Voltec warranty.
 

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Discussion Starter #5
Dennis - did they find a coolant leak or low coolant level? Or was it just the codes popping up?
 

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Dennis - did they find a coolant leak or low coolant level? Or was it just the codes popping up?
No leaks, just codes. The coolant level sensor was reading 300k ohms. Indicating a potential ground isolation fault in the switch. After the software reprogramming, the value registered 3000k ohms. They cleared the codes and all has been good ever since.

I was prepared for them to replace the coolant sensor. But was pleasantly surprised when they said it was just a simple software fix.
 

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Discussion Starter #7
While I was on the phone with Chevy customer service this morning trying to push this along the service writer from the dealer called and said they "found a way to get it under warranty". Got the Volt in this afternoon, did the update, plugged it in at home and got the green light and the beep, so it looks like it started to charge. Will check it later for a full charge. Crossing my fingers everything stays good.

Thanks to Dennis and everyone else that left dozens (hundreds?) of posts on this over the years that let me know this wasn't my problem/cost so that I pushed back and got someone to do the right thing.
 

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You should be good to go. Glad you were got it fixed under Voltec warranty. There seems to be a rash of SHVCS lately. Most appear to be the same issue fixed with a software update.
 

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I got the SHVCS message a month ago on my 2014. Took it in and the coolant actually was low. No leaks were found. This was probably the first time that coolant was added.
 

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No leaks, just codes. The coolant level sensor was reading 300k ohms. Indicating a potential ground isolation fault in the switch. After the software reprogramming, the value registered 3000k ohms. They cleared the codes and all has been good ever since.

I was prepared for them to replace the coolant sensor. But was pleasantly surprised when they said it was just a simple software fix.
I was not so "pleasantly surprised" with the software update because my cas uses now only 9kwh instead of 10kwh before the update, seems like they inceased the buffer of the battery.
At first they charge me for 2 module reprograming but few weeks after, I send them the bulletin PIC5920J and they say there was a mistake and return the amount that was charged.
Did you observe some kwh lose and range, like 10%?
 

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Discussion Starter #11
Last April I had an update performed that I believe was the cell re-balance thing (N172130462 PCM PROGRAMMING). As that was at the end of winter and we don't do alot of full discharges I didn't/couldn't get alot of data on full kwh. A few months later (Sept) I put new tires on and then winter came again and I pretty much figured any range loss, etc. was due to new tire break-in and winter driving. But, to answer your question more directly, I have noted that full discharge is giving me around 9.2-9.4 kwh pretty consistently with an occasional 10+. It's the occasional 10+ that puzzles me a bit. Very consistent 9.4 (32-34 miles on the GOM, which is pretty accurate when all said and done). I know my wife has a bit of a heavy foot and she does most of the weekly miles so that can throw the calculation off, but when I drive and get 3.5+miles/kwh it still stays at 9.4. And then a one-off at 10+, hardly anything at 9.7-9.9, just the quick spike and then back to 9.4. There were a couple of posts about needing 10-12 full discharge cycles to re-calibrate the balancing software but I'm sure I've done that by now.
 

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I did more then 12 full charge discharge by the book, 2 hours before pluging and let it 2 hours after...no improvement at all maybe a little bit worst, from 9.3 first day after the update to consistent 9kwh used now. I get the update after service high voltage charging system, not propultion power reduced but it sees it does the same reballancing bull ****. Before the update I get 9.8-10.2kwh...
 
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