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Check Engine Light for 3 weeks & getting run-around

12K views 13 replies 10 participants last post by  Chevrolet Customer Svc 
#1 · (Edited)
I've had my Volt for almost 3 years. My car got a check engine light a few weeks ago, on a Sunday. Because I plan on keeping this car for a long time (most awesome car I’ve owned), I bought the 4 book shop manual for it and I already have a code reader. I pulled the codes (p0aa6 & p1e00) and looked it up in the shop manual. It said that I may have low battery coolant, so I checked it and sure enough, it was low. I added some to it and took it in to Bay Chevrolet in Mobile AL that Monday.

I explained to their Volt guy what happened. He kept it for a day and said that the light wasn’t because of coolant, but because of a tech bulletin to reflash the generator firmware. They said they needed to order some parts for it, but it’s okay to drive it in the mean time, with the light on. I call once a week to check the status of the parts and this last time, he tells me that the coolant jug is backordered. I expressed my concern of driving around with a check engine light and asked if he could at least reflash my generator to get rid of the light until the parts come in. They tell me to bring it in the next day and they keep it all day again.

When I called to check on it, they said they can't get the code to go away because the new coolant jug has a new sensor on it that the car is looking for. That’s what got me. My car has suddenly become aware of a sensor that it wasn't manufactured with and is now looking for it. They also said that they can't reflash the firmware because the new firmware will also look for this sensor as well, which makes more sense. I can’t shake the idea that the missing coolant may be in the battery, as I've read elsewhere.

I don't mean to vent, but I don't know what else to do. I really like the car, but these guys giving me the run-around is starting to wear on me, especially with the bumper to bumper warranty expiring in 4 months/2000 miles.
 
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#2 ·
I'm surprised you'd need a new coolant jug. That just seems odd. Have you talked to your Volt Advisor about this?

Did the check engine light come back on after you filled the coolant and cleared the code yourself?
 
#4 · (Edited)
P0AA6 is not directly related to a loss of RESS coolant, although that could trigger this DTC if it was VERY low or if an incorrect coolant was added. A small amount of coolant in the battery box is essentially harmless but still needs to be properly identified, isolated, and repaired. In fact there is a recent revised bulletin PI0961 to do assist the technician in doing so.

But P0AA6 is a general "loss of isolation" DTC that sometimes can be very difficult to deal with.
It essentially means there is some sort of electrical "leakage" or loss of insulation between the high voltage system and chassis ground. Yes, there is another bulletin PIC5920 detailing to reprogram a particular module for a potential false triggering of this DTC but if it continues to set after that, you probably DO have a "loss of isolation" and they can be some of the most difficult to isolate to root cause and repair. In that event this same bulletin includes an isolation diagnosis worksheet to assist the technician in its diagnosis but it can take some time as it's a process of elimination.

That all being said,
You mention you added coolant. Did you remove the anti-tamper bracket to do so?
What type of coolant did you add? Did you mix it to 50:50 yourself and if so, what type of water did you use?
Did you inform the dealership you added coolant?
WOT
 
#5 ·
Something seems a little off here. Has anyone else seen a tech bulletin for a generator reflash? There was the inverter software upgrade, but that has nothing to do with the coolant, and there are no parts required.
I don't see why you would need a new coolant reservoir. Until this year, they were all filled only to the minimum line, so it wouldn't take much to trigger the low coolant warning.
Other than the inverter software, the only service bulletin I know of is the new one to check the coolant system and top it off. Again, unless there was a leak, you wouldn't need parts.
 
#6 ·
The Coolant thing was part of the original battery tunnel reinforcement "recall", OP's car is of the age it would have required it. The sensor the OP is mentioning would have been installed at that time, as its to throw the code when coolant is low, so it would seem the OP never did that tunnel reinforcement.
 
#7 ·
Hello The Shocker,

I’m really sorry you are experiencing this and I understand how frustrating the situation must be. I have an internal resource that just took a look at your post and we think we may have a solution for the concern you’re describing. Please send me a private message with your VIN and the dealership your vehicle is being serviced at. I want to assure you that all work will be covered under warranty because it is related to the battery. I’ll keep a look out for your message.

Katie O.
Chevrolet Customer Care
 
#8 ·
#9 ·
Getting service on a Volt is spotty .. at least in the less Volt friendly states. I was told that many dealerships are choosing to give up their Volt certification. I was told there are only 3 certified Volt mechanics in the state of LA. I am not sure how true that is, but what happens if I get service at a dealership that does not have a certified Volt mechanic. Chevy needs to do something to jump start the selling of Volts again.

Who want to drive a car 100 miles to get it fixed....
 
#10 ·
Sounds like my dealer is doing this same coolant reservoir temperature sensor replacement on my Volt.

On Monday it was 95F and 60%RH here in Minneapolis. I was driving from work to the golf course for an afternoon of enjoyment. Just before I get to the course I noticed the CEL and High Voltage Charging System error. Hmmm… it's been only a week since I had my last one of these.

I dropped it off yesterday morning at the dealership thinking it would be something simple. Nope. Coolant tank removal and replacement of sensor inside the tank. The dealership isn't far from where I work and it isn't a whole lot of inconvenience but I'm guessing this is my sixth or seventh trip to the dealership in less than twelve months for various CEL and HVCS issues. My patience is wearing down but it's a lot thicker with the gas savings the car provides. If it were an ELR I would be really p*ssed.
 
#11 ·
Apparently the coolant tank sensor did not resolve the issue with my Volt. Unfortunately the next thing GM wants the dealership to change requires more parts that are not available locally. So I have my Volt back but it is not chargeable. I will drop it off again next Tuesday for another round of troubleshooting and debug.
 
#12 ·
Hello Mike Michaels,

I apologize you are experiencing this, as I understand it is extremely frustrating. I am happy to create a case in our system and pass it to your Volt Advisor to review. They may be able to provide additional assistance with the dealership to help get this resolved. Please send me a private message with your VIN if this is something you are interested in.

Katie O.
Chevrolet Customer Care
 
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