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Discussion Starter · #1 ·
So, I was driving around tonight as i often do to kill time before my shift starts (I work third shift). And after driving i stop at a park to throw some trash in the trash can. I get out leaving the car on in park go to the trashcan come back and start to leave again. This took maybe 30 seconds.

I'm in a parking lot regenning down to a stop for a stop sign when the car shudders and I start getting errors on the display;

1. Stabilitrak issue detected
2. ABS issue detected
3. Service transmission.

So, I'm confused since i bought the car brand new on December 17th 2017 and have never had a single issue at all. I drive about a 1/4 of a mile down the road everything feels fine and I stop at a church parking lot and turn the car all the way off open the door then close it again. I restart the car and the warning lights are still there so i pull away and not 50 feet down the road the lights go off and everything is fine again.

I get home about 5min later thinking maybe its my 12v battery starting to **** the bed. So i pull out my meter and with the car off it reads 12.99v and with the car on it reads 14.1v. I assume thats totally normal specs?

I got two emails from OnStar one about the ABS fault and one about the Stabilitrak fault. I use the app to check for any diagnostic issues and there are none same on the web portal.

I saw in another old thread about a service tech had told one of out members that some codes he was seeing might be a scheduled firmware reset. Is that a thing?

Thanks all for any thoughts you may have.
 

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I saw these warnings a couple years ago. I would see them in the afternoons, but they would clear overnight then return the following afternoon, intermittently. Eventually, they warnings began appearing more regularly so I took it in and it was repaired under warranty at just under the cutoff on the 3 year\36K terms.

What turned out to be the issue was a plastic brake pedal sensor that retails for around $25. Despite rarely using the brakes, my guess is either the part is flimsy, or test drivers when new, before I bought it with 30 miles on the odometer had put it through some stress testing. I would guess with diagnostics, the service would be $200-300, though they might not do as much diagnostics if not under warranty if the systems are relatively common. This part and failure are likely common with ICE models.
 

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Discussion Starter · #3 ·
I saw these warnings a couple years ago. I would see them in the afternoons, but they would clear overnight then return the following afternoon, intermittently. Eventually, they warnings began appearing more regularly so I took it in and it was repaired under warranty at just under the cutoff on the 3 year\36K terms.

What turned out to be the issue was a plastic brake pedal sensor that retails for around $25. Despite rarely using the brakes, my guess is either the part is flimsy, or test drivers when new, before I bought it with 30 miles on the odometer had put it through some stress testing. I would guess with diagnostics, the service would be $200-300, though they might not do as much diagnostics if not under warranty if the systems are relatively common. This part and failure are likely common with ICE models.
Thats interesting because just almost 2 weeks ago i had two very hard braking events in the same day. The first one was to stop for a deer which i avoided the second that very night a racoon waddled out in front of me on a back road and i slammed on the bakes but couldn't avoid it and it cracked my grill and somehow shattered the active cooling shutter assembly as well.

You don't happen to know exactly what part it was or where it is located?
 

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Thats interesting because just almost 2 weeks ago i had two very hard braking events in the same day. The first one was to stop for a deer which i avoided the second that very night a racoon waddled out in front of me on a back road and i slammed on the bakes but couldn't avoid it and it cracked my grill and somehow shattered the active cooling shutter assembly as well.

You don't happen to know exactly what part it was or where it is located?
Maybe ACDelco® - GM Original Equipment™ Brake Pedal Position Sensor

Not entirely sure since they did it all, and not sure if there are any recalibration or code clearing stops. Someone around the forum certainly has a service manual and may be able to provide more DIY insight.
 

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This might be helpful, not a Bolt but the part is used on several GM models apparently. It looks fairly straightforward, but he does mention possibly needing to recalibrate, not sure what is involved there.

Good luck.
 

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Discussion Starter · #6 ·

This might be helpful, not a Bolt but the part is used on several GM models apparently. It looks fairly straightforward, but he does mention possibly needing to recalibrate, not sure what is involved there.

Good luck.
Thanks man. I have the service manual and its not super helpful since you have to do a learning/calibration when you replace that sensor which i don't have the proper scan tool to do so. Its not even clear thats the issue. I have a very old tuner/scantool i had for my old 2005 mustang that can read codes and it didn't find any but i can't look at any logs or anything like that with it so as long as it works i'll just leave it as is but if it happens again i'll probably get it checked out. or buy a scan tool lol whichever is cheaper.
 

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Discussion Starter · #7 ·
It did it again tonight at i was able to pull some codes but i can't find these codes anywhere on Google or in the service manual.

C3107
5 instances of P0000
C296E

Guess i'm going to have to go to the dealer. Of course 1 week before vacation.
 

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Testing battery with voltmeter is not the way to go.
You should use device that can account for temperature while testing and applied load to measure battery state of health .
Test battery terminals for loose fit or corrosion.
That would be your first step in getting problem resolved.
 

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Discussion Starter · #9 ·
Testing battery with voltmeter is not the way to go.
You should use device that can account for temperature while testing and applied load to measure battery state of health .
Test battery terminals for loose fit or corrosion.
That would be your first step in getting problem resolved.


ok so a standard volt/ multi meter that mechanics and anyone else has been using for decades and decades is suddenly not good enough to do a quick check of battery voltage? Ok sure.
 

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ok so a standard volt/ multi meter that mechanics and anyone else has been using for decades and decades is suddenly not good enough to do a quick check of battery voltage? Ok sure.
@EV Engineering is just pointing out that a 12V battery can show a normal voltage without any load, but then fall dramatically when a load is applied. A voltmeter will only show you the voltage without any load, which tells you something, but doesn't mean your battery is actually healthy.

A lot of discussion in this thread, starting post 27:

Edit: To be clear, the way your 12V battery might still be the cause of the problem is that the voltage might fall too low when your car starts, as the startup process puts a load on the 12V battery. It's only a few seconds before the DC-DC converter applies 12-14V to the bus from the high voltage traction battery, but it might be long enough to cause a problem during startup and throw fault codes.
 

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Discussion Starter · #11 ·
@EV Engineering is just pointing out that a 12V battery can show a normal voltage without any load, but then fall dramatically when a load is applied. A voltmeter will only show you the voltage without any load, which tells you something, but doesn't mean your battery is actually healthy.

A lot of discussion in this thread, starting post 27:

Edit: To be clear, the way your 12V battery might still be the cause of the problem is that the voltage might fall too low when your car starts, as the startup process puts a load on the 12V battery. It's only a few seconds before the DC-DC converter applies 12-14V to the bus from the high voltage traction battery, but it might be long enough to cause a problem during startup and throw fault codes.
1. In my initial post I tested the battery both with the car off and on. On with the A/C. So it was both under load and no load.
2. When it happened again last night I was driving down the road at 55mph when it threw the faults. So, similar to the first occurrence in that the car had been on a driving for 15+ minutes or more and not turned off when it threw the errors.
3. I’m not an electrical engineer. I just wanted to check if the battery was blatantly and obviously low on voltage. I wasn’t going to go super down the rabbit hole with lead acid battery operational theory.
 

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1. In my initial post I tested the battery both with the car off and on. On with the A/C. So it was both under load and no load.
When the car has been on for more than a few seconds, the voltage you see isn't from the 12V battery, but from the DC-DC converter pulling power off the high voltage traction battery. That's what provides the power for stuff like your A/C, etc. and is also why the 12V battery in the Bolt can last a long time (not really used much).

2. When it happened again last night I was driving down the road at 55mph when it threw the faults. So, similar to the first occurrence in that the car had been on a driving for 15+ minutes or more and not turned off when it threw the errors.
This pretty much indicates it's probably not your 12V battery, but it might be the DC-DC converter on the 12V bus or some other cause.

3. I’m not an electrical engineer. I just wanted to check if the battery was blatantly and obviously low on voltage. I wasn’t going to go super down the rabbit hole with lead acid battery operational theory.
You posted on a forum asking for help, and people are just trying to help. Testing a disconnected 12V battery with a voltmeter doesn't mean the battery is fine, that's all.
 

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1. In my initial post I tested the battery both with the car off and on. On with the A/C. So it was both under load and no load.
2. When it happened again last night I was driving down the road at 55mph when it threw the faults. So, similar to the first occurrence in that the car had been on a driving for 15+ minutes or more and not turned off when it threw the errors.
3. I’m not an electrical engineer. I just wanted to check if the battery was blatantly and obviously low on voltage. I wasn’t going to go super down the rabbit hole with lead acid battery operational theory.
MichBolt is right in that a simple unloaded test of voltage isn't a particularly great test. A low voltage reading would be something worth investigating, but a high voltage reading is no guarantee that the battery's health is all that great. So it's something that's quick and easy to do as a first step, but it's not the end of diagnosis flowchart.

And he's also correct that when you have to car turned on what you're really testing is the output of the Accessory Power Module, which provides power to the car's 12V systems (including charging the 12V battery) from the car's high voltage battery pack.

Codes that show up well after the car has been turned on seem unlikely to me to be a 12V battery problem, since all of the 12V systems will be been powered by the APM for some time. But if the 12V battery is weak then it's possible evidence of a problem with the APM itself, which might mean that the 12V battery isn't being charged properly or is discharging while the car is running and therefore ends up needing replacement anyway.
 

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MichBolt is right in that a simple unloaded test of voltage isn't a particularly great test. A low voltage reading would be something worth investigating, but a high voltage reading is no guarantee that the battery's health is all that great. So it's something that's quick and easy to do as a first step, but it's not the end of diagnosis flowchart.

And he's also correct that when you have to car turned on what you're really testing is the output of the Accessory Power Module, which provides power to the car's 12V systems (including charging the 12V battery) from the car's high voltage battery pack.

Codes that show up well after the car has been turned on seem unlikely to me to be a 12V battery problem, since all of the 12V systems will be been powered by the APM for some time. But if the 12V battery is weak then it's possible evidence of a problem with the APM itself.
I think 'she' would be more accurate . :)
 

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Based on another thread on this forum, I bought and use a cigarette lighter USB charger which displays battery voltage and also displays the current being drawn when you plug in something to charge. It is a convenient way to monitor your 12V battery. Something like $10 on Amazon.
 

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Based on another thread on this forum, I bought and use a cigarette lighter USB charger which displays battery voltage and also displays the current being drawn when you plug in something to charge. It is a convenient way to monitor your 12V battery. Something like $10 on Amazon.
By this you are only checking on boards charging system for voltage....checking battery from cigarette lighter is not ever going to give true SOH on 12 V battery. By time you discover your 12V battery is not holding healthy voltage it will be already late.
12 V battery need to be checked under load and with testing tool that can take temperature and battery information in the account before it will give you SOH
 

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Discussion Starter · #18 ·
I know this is old but as an update i was finally able to get this checked out (while doing the battery recall) and turns out i need new axle shafts. I noticed lately that i was getting a lot of what i would call "slop" upon applying acceleration in low speeds kind of like when one is in a drive through and you have to inch forward a bunch. It also felt ever so slightly odd driving at low speeds like under 10mph like it just didn't feel sure footed, if that makes sense. So, basically the computers every now and then couldn't get a good reading on what was going on with the drive shafts with all that play going on and would throw faults for Stabilitrak and abs.

$1000 at the stealership to fix it for some reason axle shafts don't count as part of the 60,000 mile drivetrain warranty. FML
 

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I know this is old but as an update i was finally able to get this checked out (while doing the battery recall) and turns out i need new axle shafts. I noticed lately that i was getting a lot of what i would call "slop" upon applying acceleration in low speeds kind of like when one is in a drive through and you have to inch forward a bunch. It also felt ever so slightly odd driving at low speeds like under 10mph like it just didn't feel sure footed, if that makes sense. So, basically the computers every now and then couldn't get a good reading on what was going on with the drive shafts with all that play going on and would throw faults for Stabilitrak and abs.

$1000 at the stealership to fix it for some reason axle shafts don't count as part of the 60,000 mile drivetrain warranty. FML
Axle shafts ARE part of GM's powertrain warranty. Can you post the part #s that were replaced? How many miles are on your Bolt?
 

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Discussion Starter · #20 ·
Axle shafts ARE part of GM's powertrain warranty. Can you post the part #s that were replaced? How many miles are on your Bolt?
Do you have any concrete documentation or proof? I’m trying to get them to email me an invoice so I can see the part numbers but it been nearly 2 hours and no email. They claim based on the part number that it isn’t covered by the drivetrain warranty.
 
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