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I hoping in 10 or less years we'll have full access to the tech inside our Gen1 Volts, up to and including a 3rd party 2-4x battery capacity replacement.
Yes, the dream.
 

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Discussion Starter #22
Thanks for all of the responses!

So, if the temp sensors decide to fail, is the car totally undriveable or will it run on the ice?
 

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Thanks for all of the responses!

So, if the temp sensors decide to fail, is the car totally undriveable or will it run on the ice?
I would answer that question this way. The ICE in your 2012 Volt functions as a generator, not as an automobile engine. When the battery state of charge drops to the "switch to gas" level, the smaller motor MGA is clutched to the engine, starts it, and is then cranked by the engine as a generator. To extend the range, the Gen 1 motor uses gas-generated electricity as fuel and the battery as a "buffer of borrowable power." The Gen 1 Volt is propelled by the larger motor MGB 100% of the time. Any excess generator output is put into the battery, and then used by the motor. If generator output is not sufficient to meet a power demand (for example, you floor the accelerator to pass someone on the highway), the motor "borrows" some power from the battery buffer, and when demand lessens, the generator recharges the battery to the "switch to gas" point. The gas-generated electric propulsion system requires a battery buffer for its operation.

Under certain conditions when the range is being extended (when smoothly cruising at 35 mph and above), the ICE/generator combo may be clutched to the drivetrain to improve fuel consumption efficiency (I call this "engine-assisted electric propulsion"). When a performance request is made (same example, you floor the accelerator to pass someone), the computer switches the system out of two-motor ("split-power") configuration and back into one-motor configuration, i.e., 100% (gas-generated) electric propulsion. The Gen 1 Volt is not engineered to be propelled by the gas engine only.
 

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I would answer that question this way. The ICE in your 2012 Volt functions as a generator, not as an automobile engine. When the battery state of charge drops to the "switch to gas" level, the smaller motor MGA is clutched to the engine, starts it, and is then cranked by the engine as a generator. To extend the range, the Gen 1 motor uses gas-generated electricity as fuel and the battery as a "buffer of borrowable power." The Gen 1 Volt is propelled by the larger motor MGB 100% of the time. Any excess generator output is put into the battery, and then used by the motor. If generator output is not sufficient to meet a power demand (for example, you floor the accelerator to pass someone on the highway), the motor "borrows" some power from the battery buffer, and when demand lessens, the generator recharges the battery to the "switch to gas" point. The gas-generated electric propulsion system requires a battery buffer for its operation.

Under certain conditions when the range is being extended (when smoothly cruising at 35 mph and above), the ICE/generator combo may be clutched to the drivetrain to improve fuel consumption efficiency (I call this "engine-assisted electric propulsion"). When a performance request is made (same example, you floor the accelerator to pass someone), the computer switches the system out of two-motor ("split-power") configuration and back into one-motor configuration, i.e., 100% (gas-generated) electric propulsion. The Gen 1 Volt is not engineered to be propelled by the gas engine only.
To answer the original question, so if the temp sensor that senses it’s too cold to cause ERDTT were to falsely say it’s too cold, then the generator could be stuck running to warm the coolant.
 

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The battery temperature sensors are different than the outside air temperature sensor.
A battery temperature sensor that sensed the BATTERY is colder than an ideal amount will use some of the battery power to run resistance heaters in the battery to warm the battery to a temperature that can more efficiently convert the stored energy into amperage. No ICE is needed.
An outside air temperature sensor that senses the air is colder than some thin-blooded software writer in southern California thinks is "cold" will start the ICE for the purpose of adding waste ICE heat to the cabin for the comfort of the operator and passenger. This is the "Engine Run Due To Temperature" pseudo-feature that I have selectively defeated on my 2014.

I still draw 3 to 5 kw for battery self-heating on cold mornings until the battery warms to its designed operating temperature.

I would expect that the battery temperature sensors could be bypassed in much the same way as I bypassed the one outside air temperature sensor, but I don't recommend it.
The battery temperature sensors not only detect when the battery is less than an optimal temperature and send a signal that works to warm the battery, but they also detect when the battery is above an optimal temperature and send a signal that works to cool the battery. Replacing the variable resistors within the battery with fixed resistors could result in battery operation well out of design limits and potential battery damage.
 

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Discussion Starter #26
For fun, I just checked the battery cells for voltage difference and I only got 20 mV, so the battery is doing fine so far.
I might even keep the car, even with the risk of it failing and not getting serviced....
 

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Yeah dealer shops are probably going to dwindle as times goes by. I'm betting my 2018 LT will last longer than I do, with a lot less surgery than I'm going to need. If it disappoints me, I will dump it.
😂 The point in our life when not needing to buy a car anymore is not necessarily a good news.
 

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I currently own a 2012 Chevy Volt with 145 000 miles. I've had no problems with it but recently, I found out that my local dealership doesn't do repairs on Volts anymore. That bugs me quite a bit and I'm thinking of getting rid of the car.
My concern is mainly the battery temp sensors, but how big of a concern that is, I don't know.... Are there any other big risks to be aware of?

I wouldn't want to sell the car but if there's a chance of it failing for a stupid reason like the sensors and not being able to have it fixed locally, I'd better swap it for some other car....
I feel your pain. I have driven past two other dealerships to get to the only dealer interested in fixing my 2014 Volt- the one that sold it to me used. They even text me all the time when Onstar thinks it needs an oil change!
 

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Check neighboring dealerships. The dealership I normally go to 18 miles away stopped because their volt technician had a health issue and had to stop working. They are between a rock and a hard place because they have the tools, but the training is no longer available. Meanwhile, the dealership 3 miles from me as well as the dealership 20 miles the opposite direction of the first dealership continues to service Volts.

I ran into an even worse problem when considering an ELR. The closest dealership that could service the ELr was over 75 miles away... ironically a Cadillac dealership in a really, really small town. None of the dealerships in the bigger towns near me have an ELR certified tech.
I have a Volt and an ELR I found that my local Cadillac dealer won't service ELR's so I had to drive about 30 miles to another dealer. Fortunately they are an amazing dealer in the Phoenix area.
 

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Discussion Starter #30
One last question about the battery temp sensor failure: is it true that the problem is more common in models starting from 2013?
 

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The Chevy tech won’t have access to the ELR software updates. Sure, the Chevy dealership can probably do the oil changes, brakes, suspension, spark plugs, fluid changes, etc. After test driving the ELR, it is amazing how the car drives very differently. When you floor it, the ICE kicks in and the acceleration easily beats the volt.
Why wouldn't the Chevy tech have access to the software? ACDelco (GM) techline is one single subscription. Are you sure about? I have taken my ELR to my Chevy dealership for the software updates in 2018.
 

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Well, if I don't have a place to have my Volt serviced, the same goes to a Bolt...
Not necessarily. Our local GM dealer sells and services Bolts but never sold or serviced Volts. (They went Bolt after the Volt was discontinued, change of ownership around that time).
 

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I currently own a 2012 Chevy Volt with 145 000 miles. I've had no problems with it but recently, I found out that my local dealership doesn't do repairs on Volts anymore. That bugs me quite a bit and I'm thinking of getting rid of the car.
My concern is mainly the battery temp sensors, but how big of a concern that is, I don't know.... Are there any other big risks to be aware of?

I wouldn't want to sell the car but if there's a chance of it failing for a stupid reason like the sensors and not being able to have it fixed locally, I'd better swap it for some other car....

I have 2012 Volt with 150k, 85% EV mode. Not concerned with service in Frederick MD area. Three local dealers seems to have qualified EV technicians on staff. I am confident if something breaks they can fix it. As an FYI, I drive cars until they stop so service long-term is important to me. Volt replaced 2001 Malibu with 324,000 miles on it. My concern is with GM expertise being provided to service technicians. My Volt ran literally problem free from purchase on 5/31/2012 until 11/19/2019. Had vehicle in for recall service, reprogramming of HPCM2. Since then my car has never been the same. Less range, less usable kWh. Range went from 36-38 to 26-30 and usable kWw on dash dropped from 9.7/9.8 to 8.4/8.8. Only good part there is vehicle charge time dropped from 3.75 hours to 3. Vehicle engages engine when batteries are fully charged randomly between 42 and 61 degrees. Call to GM ended with them sending me to dealer, who said per GM engine was engaging due to low temperature. Prior to recall reprogramming engine came on at 24/25 degree F with accompanying engine running due to low temp splash window. Low temp splash never comes on now. When I called GM they referred me back to dealer and supported dealer opinion of vehicle being okay. If GM is providing this information to dealer, I question GM expertise. Last note, reprogramming gave my Volt a Prius mode. If you have ever driven a Prius my car acts just like it. Will depart with vehicle during 2021, next vehicle not GM. Not because of service, most due to lack of confidence in manufacturer.
 

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....rather than my wagon being swept away in the river
or little Suzie getting typhoid fever)
Just keep Suzie away from Mary and she will be fine.
 
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