[clublife.peoria]

Hi,

New member here with a 2012 Volt. I purchased this wonderful car last August with a little over 60,000 miles and am currently at 76,645 miles on the odometer. Unfortunately it has recently lost brake assist after a tow (you have to press the brake all the way down to get even a hint of braking force), the e-brake does not engage with the rocker switch, speed is limited to approximately 30MPH, and Service Stabilitrak keeps coming up on the DIC.

I have recently replaced the following front end components:

• Both CV axles (due to clicking on right turns)
• Both lower control arms (ball joints were shot)
• Left front wheel bearing (to solve "Low Traction" message)
• Both outer tie rod ends, both front struts, and strut mounts.

The last few days the car was not wanting to run on battery power only and kept displaying the "Reduced Propulsion Power" message. I drove it that way until it could not move reliably. The dealer mentioned that the battery pack may need to be replaced, at a cost of $12,100. They did not mention what the braking issues could be, stating that it needs a full diagnosis (but could possibly have been caused by towing it on a rollback with the rear wheels on the ground).

Questions:
1. Could there be possible damage done from towing the car with the rear wheels on the ground? I had the tow driver put the car in Neutral, turn off the e-brake, and left the keys inside the car with the ignition on (assuming the CVT transmission needed its pump running like most automatics). We did not turn off the Traction Control or Stabilitrak systems.
2. Is there a reliable source for aftermarket high-voltage batteries for the Volt? $12,100 seems rather steep and is more than I paid for the car. I would be good with a battery that's 1/2 the cost, but don't know how good the aftermarket batteries are for range and reliability.

The car currently has the following codes:

• P1E00
• P0BC5 (Hybrid Battery Temperature Sensor E Circuit High)
• P0C4A (Hybrid Battery Pack Coolant Pump Control Performance)
• P1E00
• C1221
• C1222
• P0BC5 (Hybrid Battery Temperature Sensor E Circuit High) x2
• P0C4A (Hybrid Battery Pack Coolant Pump Control Performance) x2

It is not drivable at all and I would like to get it back on the road soon - when running, it was absolutely the best vehicle I have owned!

Thanks!

 

[leppard3]

I do not know what damage could have occured during towing, but it specifically states the Volt should be towed on a flat bed, no wheels turning on the ground. Being a 2012, does it have the original 12V battery, a failing battery causes all kinds of weird things to occur.

 

[jayoldschool]

How old is the 12v battery?

 

[hellsop]

Did they LEAD with "Oh your battery may need replacing" or did that come after a chunk of diagnostic work? If they led with that, they want you to go away because charging people $75 for oil changes is easier. I'm not a professional but I can read a manual and the 2012 service manual can be downloaded from many places on the internet. So I'm without more than "having read the board here for five years" and this manual.

According to the codes, you got two problems.

The C codes are brake related and C1221 is a speed sensor malfunction. We've seen the rings that generate the "tone" that the sensor reads the "pitch" of fail in Gen 1s a fair amount. The ring's plastic just kind of disintegrates, it breaks a little, and the debris turn the rest of the ring into crunchy bits shortly thereafter. So that's probably a "clean out and replace a part" fix. I don't know what downstream of that systemically could make the brake need a lot of pressure, but it's not impossible that the failure of the speed sensor could disable the regenerative braking entirely and leave you with the friction brakes only, and possibly the power assist for that. (That's pure speculation, though.)

The other one is a little more complicated. You've got a sensor saying "Hey, there's a hotspot on the battery", and code that says "we told this cooling pump to turn on and the coolant didn't enough cooler when we did that". Item 1: Did you get the update that deals with failing temp sensors on the batteries? It started covering just one year, and then expanded into a bunch of other years, including my 2012. That update allows the Volt to ignore a couple of failed temp sensors, because those are, indeed, impossible to replace without replacing a battery section. Which costs $3-4k. Pretend you're replacing the WHOLE battery instead, roll in a day and a half of labor, and that's probably where the $12k "go away" flag-waving comes from.

The note about the cooling pump performance says that the code can be set if there's not enough coolant in the reserve tank. So check that first. Bubbles trapped in the battery can cause hotspots allegedly, and low coolant (even if you see some in the tank but not as much as "properly filled" is) introduce bubbles. There's a whole process for getting bubbles out when the coolant is found to be low or is being changed.

The other code (hot sensor) says "If this code shows up with P0C4A, go follow that diagnostic first", and the description of how the test that sets this code is run, low coolant could fail that test, too. Basically when you start the car, it runs the coolant pump for about half a minute, and sees if the coolant temp goes down, indicating that coolant is, in fact, being pumped. If the temperature doesn't go down, it sets that code. The diagnostic that goes with the code has a 20-step process about testing that cooling pump that looks like it would take a professional about 45 minutes if they hadn't done one recently. So if they haven't charged you a diagnostic fee and said they tested the pump control circuitry, they didn't do that. The outcome from that whole thing is either the circuit needs fixing any of a number of ways (because those wiring problems are making the pump not run right) or the pump is malfed and needs replacing. But there's nothing in that section that looks like to me "your battery is toast and you need to spend $12k to replace it." Instead it looks like a couple hundred for labor and a new pump and a couple gallons of new coolant.

 

[JuneBug]

The resident Volt guru on FB had this to say:

Jaryd Carvell->Hi friendly neighborhood volt tech here! As I have tried to explain to so many people in this group. The recall (GM Program #:N172130462 Issued:Mar 28, 2019) is to correct your vehicle from improperly balancing the cells over time. The balance of those cells is part of what is used to calculate the GOM. When they reprogram the module 2 things happen. The vehicle starts to properly balancing the cells again, and the battery capacity learned values are reset. Over the course of multiple charge/discharge cycles the cells properly balance, and then the module relearns the capacity and the GOM adjusts accordingly. If your GOM goes up or down it means that the car had not been properly balancing the cells for quite some time. This process happens much slower without full discharge/charge cycles and so some people the adjustments happen much quicker than others. Also not all vehicles have the same cell imbalance. Even with the bad software some vehicles were staying close to properly balanced and others were quite a bit off. If yours was one that was close to correct, not much will change after the recall. If your cell balance was off, the more it's going to change after the recall. This is why some people noticed almost no change and others have had a change in the GOM. This is also why some people have seen the change quickly and some it took a while. Complete discharge/complete charge cycles will accelerate this learning process. Oh and one more thing, the 2013-2015 volts have 9 battery temp sensors but really only need 6. There is also software included in the recall that allows the vehicle to ignore up to 3 of the redundant temp sensors if they fail, rather than having to replace them. So there are multiple reasons to have this recall performed.

The kwh used in the power summary screen is only a calculation, not a direct measurement. It can and will vary at times, especially after being reset. If you aren’t getting the same mileage you were before, it's most likely that it was inaccurately displaying higher than it should've before the recall due to improper balancing of the cells. Now that the balancing is fixed the readout is simply more accurate. The recall did not and can not change the capacity of the battery.

 

[clublife.peoria]

Thanks for all the responses!

I believe the 12V battery is original and can check when I get back from work today.

The car has recently had the recalls done for the “Propulsion Power Reduced” message and the cell balancing, immediately after the recall the EV range dropped from 35-42 miles to19-24 miles. Further full charge cycles dropped that down to around 9 miles, then the PPR messages kept coming up.

I’ve checked the coolant levels and all 3 are at their “Full” mark, with the tank on the right being slightly higher than the one on the left.

Also, after the recall for the temp sensors the car often displayed “Battery Cold, Plug In to Warm” even on days where the ambient temperature was 50-70 degrees.

My biggest concern is the E-brake - I have not taken it in to the dealer yet for a full diagnosis but was told to not drive it in this condition. It makes a ratcheting noise when you pull the rocker switch but fails after trying (and the “BRAKE” symbol on the drivers screen blinks during this process). When I bought the car 6 months ago the dealer did change the rear pads and rotors, so those are new, but I’m sure the E-brake parts are original.

 

[clublife.peoria]

Update: I’m going to take the car to another dealer which wants only $130 to diagnose everything. They are also in agreement that having the back wheels down with StabiliTrak operating could have damaged something, but won’t know until they have the car tomorrow. They asked about the recall work done and I said it “immediately dropped the EV range”, which means there still may be something wrong with the battery. Hopefully it’s a simple fix, as I plan to keep the car to at least 150,000 miles.

 

[volty25]

Update: I’m going to take the car to another dealer which wants only $130 to diagnose everything. They are also in agreement that having the back wheels down with StabiliTrak operating could have damaged something, but won’t know until they have the car tomorrow. They asked about the recall work done and I said it “immediately dropped the EV range”, which means there still may be something wrong with the battery. Hopefully it’s a simple fix, as I plan to keep the car to at least 150,000 miles.

Are you located in CA? If you are you may want to investigate if the battery is covered under the 10 year / 150K mile Voltec warranty that I believe started mid-2012 MY.

 

[clublife.peoria]

Unfortunately not. I am located in Peoria, IL. I have requested a flatbed tow truck this time to avoid further damage and should have a response from the dealer by Friday. I have also tried charging the Volt fully multiple times and driving it until the battery is depleted prior to the failure. It is now saying “4 miles remaining” but won’t even give enough power to propel the car without the gas engine running.

 

[jayoldschool]

If it were mine, I'd put the 130 towards a brand new battery and install it at home before the truck picks up. Then, charge fully, and try to drive it and see what happens. Worst case scenario: you still need service, and don't have a ten year old battery any more.

 

[Mrclean92124]

I had the same exact problem with the C code on my Gen2.

Turns out the big washer on the drive shaft, behind the wheel bearing split and opened up...it scratched up the inner race pretty good, and cut into the wheel speed sensor. This is a drive train warranty fix in CA under 10yr warranty. I understand you are not in CA. The washer cost me 3$ at the dealer and a new sensor about 6$ at rock auto. You can put a endoscope camera ($17) down the wheel speed sensor hole, and turn the wheel... it should be smooth inside all the way around. When you pull the wheel speed sensor out, it should look smooth on the bottom. If it has a groove cut in the bottom, look no further, that is the issue. If it's smooth it's probably good and the problem is the signal ring on the inside of the bearing (bearing replacement) as Helsop mentioned. It's one of the two issues.

BTW on my gen 2 i had an akward position to work with on jack stands... I put all of my 260 LB 6"7' frame into the torque wrench to tighten up to spec. I actually hurt my shoulders doing it...Much easier to do on a lift...Should be reasonable to have your mechanic diagnose.

Also the code itself tells you which wheel sensor is reading bad. On mine it was only the right front.
Your C1221 is the left front wheel...
Your C1222 is the right front wheel...

Here is a pic I took of the washer and bearing. I just had to clean up the inner bearing with a light polishing...mostly this red coating on the washer.

 

[MetasysTech]

If it were mine, I'd put the 130 towards a brand new battery and install it at home before the truck picks up. Then, charge fully, and try to drive it and see what happens. Worst case scenario: you still need service, and don't have a ten year old battery any more.

Exactly my thought.

 

[clublife.peoria]

At the dealer now. Looks like the high voltage battery pack may be rebuildable, so I’ll probably go with this route instead of a completely new battery.

 

[clublife.peoria]

Dealer called, still needs a little more time to diagnose this. I think the E-brake somehow got set during the tow and the rear E-brake is now damaged. Is there any option in the menu that would allow the parking brake to set itself? It might be an honest mistake but after speaking to the tow driver, it appears the brake “set itself” after the car got loaded up. Not sure who to believe here...

 

[clublife.peoria]

Also, the towing company says they have towed “more than 15 Volts” without this happening so they think there’s an issue with my specific car.

 

[Mrclean92124]

Nope. Get it in writing. Get in writing that the enfente is controlled by the driver. You may have go to small claims but you have a slam dunk case. Good job.

 

[clublife.peoria]

Nope. Get it in writing. Get in writing that the ebrake is controlled by the driver. You may have go to small claims but you have a slam dunk case. Good job.

Just got off the phone with the tow company. He said he regularly tows Audi’s with the electric style parking brake and it would be very noticeable if it were on. Also, the e-brake has no correlation to the hydraulic braking system, which I felt the pedal sink to the floor. After multiple presses, the brake pedal has come up to normal height, but my dash still looks like this:

I am going to wait for the dealership diagnosis as every party in this fiasco has been keeping in contact, returning calls, and staying professional, so I hope to find out sometime tomorrow what’s going on.

 

[Aus1]

Also, the towing company says they have towed “more than 15 Volts” without this happening so they think there’s an issue with my specific car.

No - I think the car applied the e-brake by itself detecting a roll away condition. The Volt is NOT designe to be TOWED ! As stated elsewhere it has to be a flat bed.

 

[FI Spyder]

Going from memory, if you look in drivers manual, it has to be a flat bed or a dolly put under the rear wheels. Volt isn't the only car like that. Those cars/trucks with internal oil pumps in their manual transmissions, need similar. My TR7 5 speed has an internal pump and its limitations are under 30 mph for up to 30 miles. People's Court had a case involving towing a Ford truck with internal pump. Towing company had to pay for transmission repairs. If you took it to court you would most likely win (of course there are legal fees unless you used small claims).

 

[clublife.peoria]

Thanks for all the helpful responses!

The dealer called this morning, it needs a high voltage battery pack (GM has a rebuild option available that would take around 4-5 business days, plus labor time to install, or a whole new pack which unfortunately is on backorder).

The brake issues seem to have been from dragging the car with 2 wheels on the ground, causing the ABS system to get too hot - says the dealer.

We will start with a high voltage battery and a brake flush and hopefully this is the end of my Volt issues and I can get this thing back on the road!