[MauiMakes]

I decided to take a chance and drive it a longer distance today. I drove from 4000' to sea level without an issue. Once I got to the flat highway and up to 45mph i lost communication with telematics module and the propulsion quit. I still had power steering and brakes and coasted into a parking lot where I reprogrammed the HPCM2 and went to work. Again at around 45mph the "service park assist" message came in so I slowed down.

I charged as much as I could at work and headed home. There were two times when the instrument cluster went bright and chimed but nothing shut down. Both of those times I was driving uphill and wasn't regenerating.

After getting to 3 miles left of range I kicked it into mountain mode and all previous symptoms showed up but I made it the 5 miles home.

My battery wouldn't charge until I reprogrammed the power inverter and the ecu. I reprogrammed the HPCM2 again but it still won't turn on without the ice turning on. I ran out of time but will see what else I need to reprogram to get it to behave normally in electric mode.

 

[MauiMakes]

I just checked it this morning and it looks like reprogramming the ecu brought it back to normal condition.

I suppose the reason I said voltage spike instead of dip in a previous post is because I don't think a dip would cause modules to go out. I could see them not working properly without adequate voltage but not need reprogramming. I'll pick up an oscilloscope from our makerspace today to try to read what's going on with the voltage when the ice kicks in.

 

[TYmrLutz]

Check this thread, it sounds similar to your case...

2014 Odd behavior and electrical issues?

Ok so I've owned this car for a year and these problems used to be every other month but now it's just getting worse. I own a 2014 Volt with the basic package I think and two big things have been troubling me. The biggest one is that when I run on the gas motor, be it on hold or when I run out...

www.gm-volt.com

 

[MauiMakes]

My mystery is somewhat solved. The 3 legs of motor A are shorted to ground. When the ICE kicks in or over 45mph high voltage starts to disrupt the entire electrical system. Has anyone here done a transaxle replacement? Is that my only option or can either motors be serviced?

 

[MikeBCo]

Major bummer. With debris found in the trans fluid, may just be safer (and less labor) to swap out the entire drive unit.

 

[MauiMakes]

I'm finding a lot more 2013 and 2014 transaxles for sale. Did anything change that would make it incompatible? Can I put a 2013 transaxle into a 2012?

 

[TYmrLutz]

I believe the answer is yes, Gen1 transaxle units are identical. One caveat is the "buzz saw" stator bearing issue some units experienced due to improper assembly of this bearing. Some were replaced under warranty early on, with a better bearing cage material and assembly instruction. Careful observation may allow detection of previous disassembly. A utube mechanic's story:

Transaxle replacement would be very involved, but little different than conventional FWD ICE car. All the power to you MauiMakes for keeping these wonderful cars rolling...

 

[MauiMakes]

Transaxle replacement would be very involved, but little different than conventional FWD ICE car. All the power to you MauiMakes for keeping these wonderful cars rolling...

I'll be paying a shop to do this. I'm not a mechanic so I'm slow and this is definitely a job that requires a lift.

Every time I think about how much I'm spending on this car I think about what my other options are. Keeping this car going always seems like the best option because the car is exactly the right size, smooth, can run ac without the ICE on, gets great gas mileage, and a whole list of other things. A model Y with a tow package would be nice but a massive monthly payment isn't for me at this point.

 

[MauiMakes]

I've found a few transmissions to buy. It looks like the '11-12 have the same part numbers but all other years are a bit different. I haven't been able to confirm that I can put a '13 or '14 in my '12. One thing I've discovered is the OPT YK8. Option YK8 means Identification Effective Point Control Interim. I can't figure out if I need that or have that. Does anyone know about this?