[scottf200]

I'm with you as far as the lousy numbers for charging the vehicle and the lack of response by Chevrolet. Since the "upgrade" I can only get about 29-30 miles on a charge. At approximately 12kwh to charge, it's hardly worth it. I was also extremely please with the car until i had the upgrade done. Too bad they won't take responsibility. It almost makes me want to use the fire excuse to get a different car.

Can you provide more details like how long you've had the upgrade and more importantly how many full cycles you've go thru? What is your typical daily drive in EV miles. Temp before and after. Garaged? Pre-conditioning?

I'm getting about 30 EV miles now with the temps in the mid 30s here in Chicagoland recently...

I wonder if it matters if you run the battery all the way down or not for those that may travel less than 30 each day.

 

[Al Micucci]

The car is used mostly from Friday to Sunday. It is my wife's and she works at home Monday to Thursday. We almost always drain the battery. It was re-programmed about 3-4 months ago and has been through at least 20 full cycles since the reprogram. The car is kept in the garage and the weather here has been pretty mild for Long Island. It is never less than 55 in my garage. It is attached to the house and well insulated. How would the preconditioning affect this? I really don't understand the benefits of pre-conditioning. That is strictly the cabin environment, isn't it? Like I said, i really don't understand the pre-conditioning aspect so if someone could explain it, I would appreciate it.

 

[scottf200]

The car is used mostly from Friday to Sunday. It is my wife's and she works at home Monday to Thursday. We almost always drain the battery. It was re-programmed about 3-4 months ago and has been through at least 20 full cycles since the reprogram. The car is kept in the garage and the weather here has been pretty mild for Long Island. It is never less than 55 in my garage. It is attached to the house and well insulated. How would the preconditioning affect this? I really don't understand the benefits of pre-conditioning. That is strictly the cabin environment, isn't it? Like I said, i really don't understand the pre-conditioning aspect so if someone could explain it, I would appreciate it.

I'm really just trying to look for patterns here. It does not appear you put that many miles on the car (20ish cycles in 3-4 months and you almost always drain the battery). I'm wondering about the pattern of driving and and how it affects the relearning. Are you guys driving it differently (pattern) than when you first got the car and it learned your behaviors. So you got the updates in Sept timeframe so I suspect your weather was still pretty mild.

I was more wondering the temps you currently driving in? Precondition does affect cabin but it would also then impact how hard the heater/fan has to work to keep up with your settings once you leave the garage. I've read that it can take as much energy to provide cabin comfort as it does to drive a modest constant speed!! If you leave at 55 degree (garage temp) and it is 50 out and then heating is not going to have a huge impact on your EV miles unless you are using COMFORT and 70+. I'm guessing all the settings affect the relearning.

 

[socaldriver]

I drive the car 5 days a week an average of 40 miles per day. Nothing has changed in my driving patten except for the mileage I am getting. With no answers coming to me and a total frustration with the Volt advisory team, I have asked them to no longer call me I have lost enough confidence in the battery and a lack of any kind of logical explaination that I have arranged an appointment with the buy back team for right after the new year. Unfortunate because until the update it was far and away the best car I had owned and my first American car.

 

[marlow]

The only problems I noted after the software up grade were associated with charging, sense then I recieved a warrenty replacement w/ Volt update and the problems are gone.

Living in Michigan, I have defenently noted my range change with the outside temp, more in CD mode than CS mode though.

Running the electric heaters at max. reduce the CD range by about 1/3.

So far this fall, it has only been cold enough a few times to trigger the running gas engine due to cold temp message.

 

[JohnK]

I've had the software update for 3-4 months. It was confusing for the first three weeks until it relearned all of the parameters. That being said, you can get widely ranging performance depending on various things.
Worst range is raining/snowing right close to freezing, defroster on, wipers on at night, no preheat cycle (last evening I got under 25 miles).
Best is when you preheat twice, fan only, fan low, air recirculation on, outside temp in the 70's (this morning with temp at 25 degrees and these conditions I got 36 miles range, but the ICE came on twice to warm the battery early in the 20 mile trip).

 

[Chevrolet Customer Svc]

@ marlow,

Here are a few things to try that might help your range out while driving here in Michigan:

* Less energy is used at low fan speeds. When using the fan, Fan Only is the most energy efficient climate setting. ECO is for moderate heater operation and is the next most energy efficient setting. Comfort provides the most comfort but is the least energy efficient.

* Use the auto heated seat feature instead of climate settings. Heating the seat uses less energy than heating the vehicle interior.

* Use remote start to heat the interior when the vehicle is plugged in to maximize the electric range by utilizing electricity from the electrical outlet.

 

[scottf200]

Just got the car home after the software update. I actually only notices 1 thing different as I looked around. Every setting I looked at was the same it seemed, tune (balance/fade), radio, etc. My EV miles for this charge was reset. It is 32 miles round-trip to the dealer and I made it home on battery but my miles this charge is at 16. Wonder to myself if the car uses that in it's estimations for a while.

 

[MichaelH]

Hello to everyone from sunny (usually) and warm (today) northern New Mexico. I had my upgrade done this past September and like most others it reset the estimated EV range just like WOT said, and after several trips/charge cycles the range estimate came back up just like WOT said. Then cooler/cold weather came along and the range and range estimate dropped accordingly, just like WOT said. With lows around 10 F and highs in the mid 30s my range estimates were in the low 30s miles. During that time the "engine running due to low temperature" occurred most days. I didn't have too many days where I actually used the whole range during that time, but the actual range was around 30.

So, I'm posting here today to say the the temperatures this week are warmer, lows in the low 20s and highs in the mid to upper 40s. I just came back from a 43 mile trip (temp 41 F out, 46 F back) and I got 40.4 miles EV range.

I have had my Volt for just over 9 months now, total miles = 11,352, EV miles = 5524 or 48.7%, CS mileage = 41 mpg.

 

[socaldriver]

Thank you for posting that. Just another good reason for the Volt team to have a tech look at my car. I am in california 75 during the day 50 at night and since the update about 3 months ago. Now I can not get over 32 miles. used to get 40 but Volt will take no responsibiity. I am glad you car reset, mine has not but again Volt does not want to hear anything negative.

Hello to everyone from sunny (usually) and warm (today) northern New Mexico. I had my upgrade done this past September and like most others it reset the estimated EV range just like WOT said, and after several trips/charge cycles the range estimate came back up just like WOT said. Then cooler/cold weather came along and the range and range estimate dropped accordingly, just like WOT said. With lows around 10 F and highs in the mid 30s my range estimates were in the low 30s miles. During that time the "engine running due to low temperature" occurred most days. I didn't have too many days where I actually used the whole range during that time, but the actual range was around 30.

So, I'm posting here today to say the the temperatures this week are warmer, lows in the low 20s and highs in the mid to upper 40s. I just came back from a 43 mile trip (temp 41 F out, 46 F back) and I got 40.4 miles EV range.

I have had my Volt for just over 9 months now, total miles = 11,352, EV miles = 5524 or 48.7%, CS mileage = 41 mpg.

 

[WopOnTour]

There are so many problems with your response I wouldn't even know where to begin. Let me leave it at this, if for the sake of argument I agree with what you say that the cold weather is the cause of the problem, then it causes me even more concern with logic skills of the Volt technology team. Why would they release a software upgrade for the car that is supposed to improve mileage but only after consecutive charges in warm weather and choose to realease such an update in the winter? It is either really poor planning or not understanding the impact of the update until after the fact. Either way it was a bad decision on the part of the Volt Team.

Thank you for posting that. Just another good reason for the Volt team to have a tech look at my car. I am in california 75 during the day 50 at night and since the update about 3 months ago. Now I can not get over 32 miles. used to get 40 but Volt will take no responsibiity. I am glad you car reset, mine has not but again Volt does not want to hear anything negative.

You can't press a button and expect someone to fly an engineer to your door.
If you are insistent you have something wrong with your car, take to a dealer. It's really that simple, that's what they are there for. If you are not happy with the service provided by your selling dealer, take it to another Volt dealer. You have many in your area.

All I am certain of is the update software itself, didn’t create your issue- JMO!. But there certainly could be something else wrong with your car that is affecting it's EV range and the association to the software update merely a coincidence.
The dealer won't/can't refuse at least checking out your car if you have any concern- just book it in, and drop it off. Assuming the in-house Volt technician doesn't find anything concrete from the car itself, (DTCs, existing scan tool data, analysis of you past drive cycle history, even performing a few full charge-discharge test cycles to verify) their next step once the reange concern is verified is for them to contact Volt Technical Assistance (VTA) for the "reduced EV range" concern and go from there. That's how it works.
They won’t fly an engineer out unless it is escalated by VTA to that level.
Good Luck!
WopOnTour

PS>Just remember this forum and gm-volt.com has nothing to do with GM or the Volt team- we're all just Volt enthusiasts. So beating your chest around here won't get you much of anything other than perhaps a wee bit of sympathy. (and even that is quickly waning)

 

[tboult]

To follow up on what WOT said.. if you keep telling them the problem is X (software update cause the problem), and they don't believe that X is the cause, they will often stop looking. If you tell them that your milage is way down from the past, and are not sure why, maybe they will dig deeper and find the real cause. Maybe there is an issue in your battery that's undiagnosed .. don't tell the what you think is the cause, don't even hint its caused by the upgrade, tell them the problem (EV range), get them to test the car. Maybe they can swap you for a demo car for a day and you can drive the same trip and show them there is a difference.

 

[WopOnTour]

To follow up on what WOT said.. if you keep telling them the problem is X (software update cause the problem), and they don't believe that X is the cause, they will often stop looking. If you tell them that your milage is way down from the past, and are not sure why, maybe they will dig deeper and find the real cause. Maybe there is an issue in your battery that's undiagnosed .. don't tell the what you think is the cause, don't even hint its caused by the upgrade, tell them the problem (EV range), get them to test the car. Maybe they can swap you for a demo car for a day and you can drive the same trip and show them there is a difference.

Great post T. Thanks for putting it out in a different fashion/manner.
Hopefully socal can at least leave the car with them so it can be charged-discharged a few times during a series of extended road tests while jacked into GDS2 in order to better quantify the extent of the range discrepancy and come up with a root cause and a suitable solution.
There's no magic wand!
WOT

 

[maynard]

Gee WOT...I am crushed. I was sure that the entire Volt team was issued magic wands. With all the neat and very technical stuff that our Volts have, I was sure that the only way those good folks could achieve all of what a Volt is, was with a magic wand. Now you tell me that they don't have a wand. WOW!!!!

 

[scottf200]

I was getting about 30 EV miles before my update. Estimate for the next several days after were like 37, 37, 34, 32, 31, 32. I actually got 29 actual miles a day or two ago.

Today I got 41 actual miles. I was using ECO this morning but went after work to play racquetball a ways away. On the way back I was still hot so I was using very limited climate controls. Pulled in home at over 41 miles driven and 1 mile left on the battery. It was 43F.

 

[kmg]

All previous concerns about the software update reducing my range... Gone.

In SoCal it has been about 60 at night and 70 to 75 during the day for the last couple of days. Temporary warm up from Santa Ana winds. Today I got 46 miles range, which is the highest I have ever seen with my car, pre or post update. Today's drive was mostly 50 to 55 mph, with a very light foot.

2011 # 1228

 

[fishhawk]

Yup, we had a nice warmup a month ago, and on that day got my highest ever electric range, 46.8 miles, in mostly moderate highway driving 45-55mph. So I'm confident my range was not adversely affected by the update. Routinely getting 38+ EV range even with the temps in the 40's in the morning.

 

[scottf200]

My 2011 Volt with the famous 2011 software update which happened in the Fall when range was dropping anyway and people were concerned about it. Today it was 64F on my way to an event and I got 48.7 electric miles on the battery. No climate controls needed because of temp. 35-45 MPH with a lot of stoplight (which I don't think were good - stop/start acceleration kW usage)

Notice that my gas_generator mileage was pretty good as well. 39.7miles / 0.79 gal of gas = 50 MPGused. Yes, the ICE stopped/started multiple times.

 

[electro649]

Here is the fix for your problem. ( Gen 1 Volt )
Purchase a used HPCM2 module from Ebay or an auto wrecker the same year as your Volt.

You can use another year Volt providing the used HPCM2 module has the same part number as stamped on your existing HPCM2 module label.

Next, purchase a programmer from the following web site:

USB Version VXDiag VCX NANO for GM/OPEL 2025.03.29 G-D-S2 Tech-2-WIN Diagnostic Tool

VXDiag VCX NANO for GM/OPEL comes with both GM Tech2Win and GDS2 software. It comes to replace GM original tool MDI and Tech2. VCX NANO GM is Compatible with applications that diagnose engines, transmissions, ABS, instrument panels and more. Techline Connect Service Programming System (SPS2)...

www.vxdiagshop.com

Download the free software to run the VXDiag programmer into your laptop running Windows.

Disconnect your 12 volt battery, ( in the trunk compartment ) and swap in the used HPCM2 module ( module is located under the passenger front seat ) it is easier to remove the 2 torx bolts and lift the seat out of the way to swap the HCPM2 module out.

Reconnect the 12 volt battery. Power up your Volt. Next plug in the VXDiag programmer into your OBD2 port ( under the steering wheel ), run the downloaded program ( from VCXDiag website ) and “reset” the HCPM2 module in the menu. ( You need to scroll down the various menus to find this “reset” option )

Once you reset the HCPM2 module, turn the Volt off and back on again. Now charge your Volt…… your battery range will come back to the original 10.3kwh ( or whatever it was before the GM dealership HPCM2 firmware update ) per full charge range.

This method works 100% because I successfully performed this on my 2012 Chevy Volt car after a GM dealership reprogrammed my HCPM2 module and subsequently I lost 1.2kwh per full charge. ( 9.1kwh )

GM dealership would not reverse the update and recover my original 10.3kwh full charge capacity. ( they told me it was a liability issue and the original factory firmware was not available anymore ) …… 🤕☹