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Discussion Starter #1
....but I'm not that worried about it as I know (having learned about it here) that it's almost certainly just the typical coolant tank sensor issue. I checked the battery coolant level and it's right where it's supposed to be with zero sign of any leakage anywhere. FWIW as well the car has had all the updates done, anti-tamper guard on the coolant tank, etc.

The car is still under the Voltec warranty so I have an appointment to take it to the dealer Wednesday.

Two questions - I hooked up my scantool and here's the codes I got:



Are these typical of the codes one would expect for the sensor issue?

And secondly, I had always been under the impression that the SHVCS code/error was only clearable by a dealer (?), but since it was stopping us from charging I commanded my scantool to clear the codes and boom, check engine light went off and the car honked, dash light turned green, and it started charging immediately. It tossed the code again the next day (Saturday) but again I reset it (with the same success) and it's been fine since, hence why I'm sure this is just an intermittent sensor thing.

Is this actually normal for those of us with our own scantools to be able to reset this, and all the stories about "requiring an expensive visit to the dealer to have it reset" is just specific to those without their own scantool?
 

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Yes. The issue is one of the codes cannot be cleared by any mean. And because it cannot be cleared the car cannot be plugin charged. The entire body management module has to be erased and reprogrammed from scratch and only a dealer has the equipment to do that.

So that is fine so long as it is still under warranty but once the Voltec warranty expires expect a $100+ bill from a dealer to reflash the module.
 

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Some dealers want to charge under warranty if they don't find anything wrong. I would push them to pay if they do this.
 

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Discussion Starter #4
Yes. The issue is one of the codes cannot be cleared by any mean. And because it cannot be cleared the car cannot be plugin charged.
Re-read my post. I cleared them. The car is charging again just fine. P1FFD remains listed as a "permanent" code (Hybrid/EV Battery Pack Coolant Level Sensor Circuit High Voltage) but aside from that the car is operating normally, including charging.
 

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Re-read my post. I cleared them. The car is charging again just fine. P1FFD remains listed as a "permanent" code (Hybrid/EV Battery Pack Coolant Level Sensor Circuit High Voltage) but aside from that the car is operating normally, including charging.
No problem. Just reset it every day with your tool, haha. For what, $30? you could have avoided all of this, the daily resets, the dealer visit.
 

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Discussion Starter #6
No problem. Just reset it every day with your tool, haha. For what, $30? you could have avoided all of this, the daily resets, the dealer visit.
Haven't had to reset it daily.

Have owned the Volt for 1.5 months and the WOT plug is on the list of things to buy...but hadn't anticipated experiencing the issue so quickly. The condescending reply was unnecessary, thanks.

My root question was with regards to the "latched code" issue I read about here over and over again. Even the WOT override plug FAQ's state the SHVCS codes as "requiring" a dealer visit to clear and be able to charge again. This hasn't been my experience.

I guess, in short, what I'm getting at is this - do I even need to bother going to the dealer Wednesday, potentially fighting with them about getting this covered under warranty, only to end up not much further ahead other then to maybe get a new battery coolant bottle with the same inherent issue? If it's going to accomplish nothing, I'll order the WOT plug tomorrow, clear the code again if it happens to make a reappearance between now and the time it arrives, plug it in when it does arrive, and live happily ever after?

The P1FFD code is perhaps the "latched" code, but I don't really care if it remains as aside from showing up on my scantool it doesn't trigger the check engine light nor seem to really have any negative effect on the car whatsoever.
 

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I guess, in short, what I'm getting at is this - do I even need to bother going to the dealer Wednesday, potentially fighting with them about getting this covered under warranty, only to end up not much further ahead other then to maybe get a new battery coolant bottle with the same inherent issue?
IMO if you want peace of mind get it re-flashed and fixed then add the WOT replacement. BTW it is not a bottle but a sensor that attaches to the bottom of the bottle.
 

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IMO if you want peace of mind get it re-flashed and fixed then add the WOT replacement. BTW it is not a bottle but a sensor that attaches to the bottom of the bottle.
A new bottle is included in the update for the 2011 and 2012 models, as well as the sensor. The original bottles wouldn't have had the molded on holder for the sensor that was added and spliced to the wiring. If the OP is lucky, the dealer will perform the update for splicing in the wiring for the sensor, will add the new bottle and will reprogram HPCM2 all under warranty, as all this was covered in GM issued recall #11188.
https://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM453335/INOT-PE11037-59136.pdf
 

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A new bottle is included in the update for the 2011 and 2012 models, as well as the sensor. The original bottles wouldn't have had the molded on holder for the sensor that was added and spliced to the wiring. If the OP is lucky, the dealer will perform the update for splicing in the wiring for the sensor, will add the new bottle and will reprogram HPCM2 all under warranty, as all this was covered in GM issued recall #11188.
https://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM453335/INOT-PE11037-59136.pdf
Thanks for the clarification.
 

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Discussion Starter #10 (Edited)
Following up....SHVCS hasn't popped up again since, so it was clearly a very intermittent problem.

Most interestingly, the P1FFD code is also gone - I scanned it last night and everything is showing completely normal again now.

I still don't understand what all the hubub about "needing" a dealer visit (and reprogramming modules etc) to resolve SHVCS is all about - it seems based on my experience that anyone with a code reader can clear the issue, activate charging again, and even the remaining P1FFD "permanent" code cleared after enough driving cycles.

I'm not going to rush for the WOT bypass at this point unless the issue turns out to be semi-regular - a once every 3 months thing I can simply clear and be done with it.
 

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Following up....SHVCS hasn't popped up again since, so it was clearly a very intermittent problem.

Most interestingly, the P1FFD code is also gone - I scanned it last night and everything is showing completely normal again now.

I still don't understand what all the hubub about "needing" a dealer visit (and reprogramming modules etc) to resolve SHVCS is all about - it seems based on my experience that anyone with a code reader can clear the issue, activate charging again, and even the remaining P1FFD "permanent" code cleared after enough driving cycles.

I'm not going to rush for the WOT bypass at this point unless the issue turns out to be semi-regular - a once every 3 months thing I can simply clear and be done with it.
It would be interesting to know if all of the codes in your case would have eventually cleared without a scanner at all. I realize this would likely require running the engine once the battery was depleted because you couldn't charge.

You may have a unique circumstance that resulted in the same general "false positive" many others are experiencing. While your situation is indeed interesting, at this point I'm still more comfortable in having bypassed the sensor all together.
 
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