[Bammerman]

This morning my Volt juddered a bit when I braked going down my hill and the "Low Traction" message came up. Then in rapid succession, "Service Stabliitrak" and "Service Brake Assist" messages arrived. A bit later the MIL or Check Engine Light came on. Subsequently I drove a mile or two to the gas station, put a few gallons of gas in the car, started it up in service mode, turned it off, and now the "Service Stabliitrak" and "Service Brake Assist" messages have gone away, but the MIL is still lit. Perhaps this is all related to my 12-volt battery? I'm taking the car to my neighborhood garage tomorrow to have that battery checked. There have been so many threads here about wonky messages due apparently to dying 12-volt batteries that I want to try to rule that out before taking the car to the dealer. Other ideas, thoughts, suggestions? And if it turns out that there are brake assist or stabilitrak issues, are these part of the "brake modulator assembly", which is covered by the warranty?
WAIT -- THERE'S MORE: after writing the above I went out and started up the car again (plugged in to charge) and the MIL did NOT illuminate. Now there are no warning messages and no warning lights. But I think I should still take the car in tomorrow to have the 12-volt battery checked -- does that make sense?

 

[Bonacci15Volt]

I had something similar happen in my Saturn Outlook, I know different vehicle, but same manufacturer (GM). I found the brake position sensor to be bad. Problem solved no more issues. Can you tell if your brake lights are on with the foot off the pedal? If vehicle is under warrantylet the dealer fix it. If not buy the part from them and replace. Just one connector and a bolt. Disconnect ground from battery first

 

[Loboc]

When codes are set, you should get OnStar to tell you what they are and recommend an action plan.

A 'judder' caused by pavement defects can mess with traction control, braking and regen. It usually doesn't cause messages and lights other than maybe traction control. Sounds like a more serious problem.

 

[somms]

This morning my Volt juddered a bit when I braked going down my hill and the "Low Traction" message came up. Then in rapid succession, "Service Stabliitrak" and "Service Brake Assist" messages arrived. A bit later the MIL or Check Engine Light came on. Subsequently I drove a mile or two to the gas station, put a few gallons of gas in the car, started it up in service mode, turned it off, and now the "Service Stabliitrak" and "Service Brake Assist" messages have gone away, but the MIL is still lit. Perhaps this is all related to my 12-volt battery?

Doubt the 12V AGM failing would cause DTCs to occur when the Volt is actually being driven but who knows...

Heck, you can even disconnect the 12V AGM while the Gen1 is turned ON and drive around w/o issue due to the fact the 14V APM is supplying DC voltage.

FWIW: I have driven around for several miles with the 12V AGM disconnected and never even seen any DTC Check engine lights come on!

 

[llninja]

During snowageddon 1, I pushed through 14 inches of snow on a slippery long driveway where traction control was struggling to move me for about 1400 feet. During that episode "service stabilitrack" appeared on my DIC and the check engine light was lit. I called Onstar, and they suggested driving a bit more to see if it disappears and if it doesn't then take it into the dealer. It never returned. I suspect that a minute or more of continued traction control caused the computer to think there was a permanent problem with the drivetrain, when in actuality, I was in conditions that caused a long traction control run.

Whenever going downhill, especially on gravel, if you are on the brake pedal, but it's really doing regen, as soon as you lose traction, the Volt will shutter forward as if your brakes are failing, when it is indeed the traction control preventing your wheels from locking up. So, how long is your hill, what type of driveway do you have, was there rain or snow, and how worn are your tires?

 

[Powered7]

To the OP, I recommend you consider bringing your car over to a Chevrolet dealer. With all of the systems the Volt has, I don't think a lot of the other places would be able to service it unless they have the necessary certification(s). For simpler things like tires, there shouldn't be a problem with taking it elsewhere though it would still be good to check if they're at least familiar with the Volt.

 

[Bammerman]

"I recommend you consider bringing your car over to a Chevrolet dealer. With all of the systems the Volt has, I don't think a lot of the other places would be able to service it unless they have the necessary certification(s)."

Powered7, actually, I agree, when it actually comes to service on the Volt. I thought to take the Volt in to the neighborhood garage (which I've used for years) tomorrow just to run a test on the 12v AGM, because my Chevy dealer couldn't take it in until next week, and those brake-related messages seemed rather peremptory. That may all be OBE, because a little while ago I called OnStar, and they ran a diagnostic on the Volt; they found "...no codes, everything seems fine." Their emailed result reads: "Through your recent On-Demand Diagnostic, OnStar did not detect any issues with your 2013 Chevrolet Volt. No service is required." So my car is fine, apparently, but I'm still wondering about the health of the 12v battery. I don't want it to quit on me when I'm out in the mountains somewhere. Thoughts, anyone? And thanks to those who've responded so far.
PS: assuming the local garage does a correct job testing the 12v battery, will they be able to ascertain the "health" and probable remaining lifespan of the battery? That is, will they be able to tell if the battery is pretty much done and should be replaced? A 12v battery is a 12v battery, right? I don't need a Chevy dealer for that, do I?

 

[Upper5Percent]

This morning my Volt juddered a bit when I braked going down my hill and the "Low Traction" message came up. Then in rapid succession, "Service Stabliitrak" and "Service Brake Assist" messages arrived. A bit later the MIL or Check Engine Light came on. Subsequently I drove a mile or two to the gas station, put a few gallons of gas in the car, started it up in service mode, turned it off, and now the "Service Stabliitrak" and "Service Brake Assist" messages have gone away, but the MIL is still lit. Perhaps this is all related to my 12-volt battery? I'm taking the car to my neighborhood garage tomorrow to have that battery checked. There have been so many threads here about wonky messages due apparently to dying 12-volt batteries that I want to try to rule that out before taking the car to the dealer. Other ideas, thoughts, suggestions? And if it turns out that there are brake assist or stabilitrak issues, are these part of the "brake modulator assembly", which is covered by the warranty?
WAIT -- THERE'S MORE: after writing the above I went out and started up the car again (plugged in to charge) and the MIL did NOT illuminate. Now there are no warning messages and no warning lights. But I think I should still take the car in tomorrow to have the 12-volt battery checked -- does that make sense?

Your Engine Control Module may be getting ready to fail...

http://gm-volt.com/forum/showthread...if-this-occurs&highlight=Service+Brake+Assist

 

[hellsop]

PS: assuming the local garage does a correct job testing the 12v battery, will they be able to ascertain the "health" and probable remaining lifespan of the battery? That is, will they be able to tell if the battery is pretty much done and should be replaced? A 12v battery is a 12v battery, right? I don't need a Chevy dealer for that, do I?

Any test that gets you an answer in less than an hour won't tell you anything meaningful, the way the Volt uses the 12v. The Volt boots computers with it, supplying sufficient power at a high enough voltage so that they can all boot in the correct order, establish communication with each other in the expected timeframe, flip the connection to the high-voltage pack, make sure THAT worked and that the APM is supplying the low-voltage bus now, then the 12v is done. It never does something a brutish as "spin an engine". but it does do some delicate work so being able to deliver power steadily over time is more important than "how much can I send in ten seconds?"

 

[TSquare]

PS: assuming the local garage does a correct job testing the 12v battery, will they be able to ascertain the "health" and probable remaining lifespan of the battery? That is, will they be able to tell if the battery is pretty much done and should be replaced? A 12v battery is a 12v battery, right? I don't need a Chevy dealer for that, do I?

In my opinion, anybody can test a 12 volt battery, but I always take a positive test result as 'maybe the battery is ok'. But, if you get a negative result, you can be pretty sure that it is bad.

 

[jbakerjonathan]

Any test that gets you an answer in less than an hour won't tell you anything meaningful, the way the Volt uses the 12v. The Volt boots computers with it, supplying sufficient power at a high enough voltage so that they can all boot in the correct order, establish communication with each other in the expected timeframe, flip the connection to the high-voltage pack, make sure THAT worked and that the APM is supplying the low-voltage bus now, then the 12v is done. It never does something a brutish as "spin an engine". but it does do some delicate work so being able to deliver power steadily over time is more important than "how much can I send in ten seconds?"

How can one tell when the system has switched to the APM (milliseconds or seconds)? Wouldn't the AGM battery only have to be stable for that length of time? How much power over what length of time is required from the AGM to effect a start-up?

When I replaced the AGM battery in a 2002 Prius I once owned, I started the car and then removed the old battery and covered the cable ends while I installed the new battery. I then re-attached the cables and I was good to go - all radio settings, etc., had remained. I'm wondering if that trick could be done with the Volt.

 

[TSquare]

When I replaced the AGM battery in a 2002 Prius I once owned, I started the car and then removed the old battery and covered the cable ends while I installed the new battery. I then re-attached the cables and I was good to go - all radio settings, etc., had remained. I'm wondering if that trick could be done with the Volt.

Yes, the Volt is no different than any other car. After the Volt is 'on' the 12 volt battery can be removed and the car will continue without issues.

 

[hellsop]

In my opinion, anybody can test a 12 volt battery, but I always take a positive test result as 'maybe the battery is ok'. But, if you get a negative result, you can be pretty sure that it is bad.

Yup. "Great! It'll start my F2500!"

 

[hellsop]

How can one tell when the system has switched to the APM (milliseconds or seconds)? Wouldn't the AGM battery only have to be stable for that length of time? How much power over what length of time is required from the AGM to effect a start-up?

One can tell when the power on the 12v posts goes from 12.x volts to 13-14 v. That's when the APM has picked up. It's not long -- I've learned that it happens in less time that it takes me to push start, release the brake pedal, get out of the driver seat and go touch the leads to the battery. Beyond that I can't tell without getting a helper, and I just don't care that much, since the Volt ALWAYS starts (there's no ICE "will it won't it" or 30 second cranking cycle), it can't be using more than 60 amps for maybe 10 seconds. Probably even less current than that, because that's the full "system running, lights on, blowers going" idle draw.

 

[TSquare]

One can tell when the power on the 12v posts goes from 12.x volts to 13-14 v. That's when the APM has picked up. It's not long -- I've learned that it happens in less time that it takes me to push start, release the brake pedal, get out of the driver seat and go touch the leads to the battery. Beyond that I can't tell without getting a helper, and I just don't care that much, since the Volt ALWAYS starts (there's no ICE "will it won't it" or 30 second cranking cycle), it can't be using more than 60 amps for maybe 10 seconds. Probably even less current than that, because that's the full "system running, lights on, blowers going" idle draw.

Since I have nothing else to plug into my 12 volt port, I got one of these:

It cycles thru Volts, Amps, & Temp. Plus it gives me 2 USB charging ports. Amps is the current flowing thru the USB ports and the temp is internal to the device. It gives accurate cabin air temps if not actively charging via USB.
https://www.amazon.com/Car-Charger-Smartphone-Temperature-Fahrenheit/dp/B00SWGWILI/ref=pd_sim_107_3?_encoding=UTF8&psc=1&refRID=ZWAW09SEQ5M6CEBZZR8M

 

[Bammerman]

Darn it, the messages came back: OnStar's diagnostic this time reports: "The code(s) and explanation(s) associated with this issue is/are:
C1225 An issue has been detected in the Traction Control System
C0035 An issue has been detected in the Traction Control System."
By the way: it's probably not the 12v battery's fault. I had it measured at the auto parts store: "585 cold cranking amps".
So I'm off to the dealership service dept. tomorrow. Wish me luck.

 

[Bammerman]

I took the Volt to the dealer today. Eventually, the service dept. (clerk? writer? representative?) said the problem seemed to be due to the axle that had previously been replaced, which would now need to be replaced again. This repair would be covered under warranty, and might solve the problem. If it did not, then the "traction control module" would have to be replaced, at a parts cost of $600 (!), and this would not be under warranty. I asked why the axle replacement would be covered under warranty but the module not be covered, if they were fixing the same fundamental problem. I could not understand her reply -- something about the part itself not being covered. It's a mystery. Is this something I should ask the Volt Advisor to get involved in -- or is it perhaps too soon for that?

 

[Bammerman]

Is the "traction control module" the same thing as the "brake modulator assembly"?
Anyone?
Anyone?

 

[Upper5Percent]

Darn it, the messages came back: OnStar's diagnostic this time reports: "The code(s) and explanation(s) associated with this issue is/are:
C1225 An issue has been detected in the Traction Control System
C0035 An issue has been detected in the Traction Control System."
By the way: it's probably not the 12v battery's fault. I had it measured at the auto parts store: "585 cold cranking amps".
So I'm off to the dealership service dept. tomorrow. Wish me luck.

C1225 - Left Front Wheel Speed Sensor Circuit Range/Performance
Erratic signal. The left front WSS is exhibiting erratic behavior with a large acceleration.

SO why aren't they checking the wheel sensor??

 

[Bammerman]

...why aren't they checking the wheel sensor?? They are, I think. The service manager says they're replacing the hub, which, if I understood him, contains the Wheel Speed Sensor Circuit. They hope this will solve the issue.

Meanwhile, I called GM -- they have referred this case to a "senior Volt advisor", who is supposed to call the dealership service department to discuss the matter. We'll see. Incidentally, the rep at GM Customer Assistance told me they no longer have a "Volt Department" there. I wanted them involved because it's impossible for me, or perhaps for most people, to understand what is really covered under the 8-yr Voltec warranty. See page 15 of your warranty booklet, in particular under "Other Voltec Components".