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snip...
The car seems to lack power in CS mode and seems to be limited in regeneration when observing the driver’s information display. We do know that in CS mode available power is not as great as when in CD mode. That is by design. However, the OP sees a maximum of 59 kW. IIRC, in CS mode the maximum should be 80 kW – someone correct that figure if need be.
Max power available in CS or CD should be the same, around 110kW. In CS mode, you are drawing off the battery buffer to hit that, but you can still hit that just fine. If you draw the buffer down too low, eventually you'll get Propulsion Power Reduced and be limited to the 55kW-ish, I believe. It almost sounds like OP is living in PPR full time, but with no errors (and PPR in CD mode with a full battery makes no sense at all). Something weird is definitely going on... very interested in what the dealer discovers.
 
I second sherpa's comments.
It's almost like you're running in Propulsion Power Reduced (PPR) mode, but that should have a message on screen and a MIL accompanying it. Very strange.

Considering the range of problems, could this possibly be a defective 12 volt battery situation ?

I was thinking that the electronics are driving from the 12 volt system, would be instructing the inverter as to how much power to produce, how much to generate, etc.

My guess is that the battery is original but I haven't looked at it.

The only anomaly beyond drivability issues is that the back door push buttons don't work very reliably. However the rear hatch has never failed to release. I replaced the button battery in all three of my remotes because one was weak.
No. If the car is on and functioning, it's on and the 12V is only along for the ride getting a trickle charge. HV+APM are providing power the vehicle during regular operations. If those die, the car would not drive.
OP would also be seeing lots of strange error messages and MILs on startup and I haven't seen reference to anything of that sort.
 
Discussion starter · #44 · (Edited)
I second sherpa's comments.
It's almost like you're running in Propulsion Power Reduced (PPR) mode, but that should have a message on screen and a MIL accompanying it. Very strange.



No. If the car is on and functioning, it's on and the 12V is only along for the ride getting a trickle charge. HV+APM are providing power the vehicle during regular operations. If those die, the car would not drive.
OP would also be seeing lots of strange error messages and MILs on startup and I haven't seen reference to anything of that sort.
What about some form of service or diagnostic mode ?

Since everything "works", just not enough of everything, I was thinking the car could be testing something or limiting power such as (possibly) during production and the car never got reset.

Or maybe the auction house reset something. I do know that in preparing it for sale, according to a card left in the glove box, they "tr/svc", "tr/recall" and "repl tire". When I bought the car, it had four different tires. One old Goodyear, one new Goodyear of same style, and two new cheapo Made in China tires from two different brands, one was the wrong size.

Just grabbing straws looking for needles.
 
I don't believe the car is driveable in service mode, it just lets the computers fully boot for testing purposes.
But you could try turning it on and off in service mode and see if it makes a difference.

Service Only Mode
This power mode is available for service and diagnostics, and to verify the proper operation of the malfunction indicator lamp as may be required for emission inspection purposes. With the vehicle off, and the brake pedal not applied, pressing and holding the POWER button for more than five seconds will place the vehicle in Service Only Mode. The instruments and audio systems will operate as they do in ON/RUN, but the vehicle will not be able to be driven. The propulsion system will not start in Service Only Mode. Push the button again to turn the vehicle off.
Notice: Service Only Mode will discharge the 12‐volt battery. Do not use Service Only Mode for an extended period, or the vehicle may not start.
Not sure what tr represents, but it looks like just regular service, recalls and tire replacement to me.
However, if one of those recalls involved HPCM2 it may have messed up the software that controls the hybrid components. Reflashing that might fix it.
 
could this car have been a tune gone wrong,,car's messed up some where
 
If it's a bad tune, that should easily be picked up when an MDI is connected. My understanding is that all modern GM ECU's maintain a record of all flashes performed. This has been a huge topic of concern since some people were flashing a tune, screwed something up, reflashed the GM approved tune and took in for warranty repair which was denied since a record of past tunes was present and indicated a non-approved flash.
 
Discussion starter · #48 ·
could this car have been a tune gone wrong,,car's messed up some where
If it's a bad tune, that should easily be picked up when an MDI is connected. My understanding is that all modern GM ECU's maintain a record of all flashes performed. This has been a huge topic of concern since some people were flashing a tune, screwed something up, reflashed the GM approved tune and took in for warranty repair which was denied since a record of past tunes was present and indicated a non-approved flash.
I sure hope that is not the case, especially since this isn't my normal dealership.

On the other hand, I know something of the original owner and have my doubts.

That said, I guess it would be nice if a reflash fixes it but I have my doubts there and one would think there are sufficient checksums in place.

The funny part is that the car does run, I'm driving it most every day. It hasn't hiccuped, belched or, well, anything else.
 
I'd bet it's just something with the existing tune that went wonky. Unfortunately it seems even though a reflash frequently just writes the same program that was there before, it seems to take care of a lot of issues when done unless it's a hardware failure of some sort. I always question how something thats been burned to a ROM can get corrupt or altered to cause undesired operation but apparently it happens as several members have had control modules reprogrammed with the same programming that was present before and problems cleared up.

It's like trying to wrap my head around a CD/DVD going bad because the written portion somehow became corrupt. It doesn't work in my head how that can happen, but plenty of evidence on here suggests otherwise.
 
Discussion starter · #50 ·
I would say your evidence for something wrong that you can take to the dealer is right there. That 59kW.

For kicks and giggles I'd be interested in what your 0-60 time is. Sounds like it could be way slower if you are in fact getting only 59kW.
Okay, I've got a number using Torque Pro on an Android phone communicating via Bluetooth to the OBD2 adapter.

It was blistering cold outside as we are down in the 50s and I had to run the defroster since it was a little drizzly. I have a friend with a long, smooth paved drive to his house on a farm that I have used it to diagnose vehicle before. (At least this time his wife couldn't complain about engine noise!) While the driveway was wet but I never spun a tire and traction control never kicked in.

Turns out that my car is truly slower than it feels. Perhaps being so low to the ground versus my truck gave me the impression that it was quicker than it really is.

I did three runs to 60 mph: 12.389, 12.667 and 12.501 seconds.

Soooo, that seems in line with the other numbers.

However one interesting thing did occur. I did see 61kW pop up on the display and stay there for a couple of seconds. So "59" itself isn't a hard point. Maybe because I had the climate control system on because doesn't that get added into the power numbers?

Anyhow, question answered and another piece of puzzle is found. Now where to put it!?
 
Discussion starter · #51 · (Edited)
I'd bet it's just something with the existing tune that went wonky. Unfortunately it seems even though a reflash frequently just writes the same program that was there before, it seems to take care of a lot of issues when done unless it's a hardware failure of some sort. I always question how something thats been burned to a ROM can get corrupt or altered to cause undesired operation but apparently it happens as several members have had control modules reprogrammed with the same programming that was present before and problems cleared up.
Or maybe the stored values / parameters / data cache gets cleared and starting from scratch solves the problem.

It's a shame that we can't disconnect the battery to reset everything like we could in the early days of fuel injection. I won a Maxima in a radio station contest in the 80s and it couldn't handle changes in altitude, but disconnect the battery for 30 seconds, reconnect and drive off and it would relearn the altitude via the MAP sensor the instant the key was turned on / before the engine started and it would be fine again. Later, I added a momentary normally-closed switch to the ground of the CPU to make that process easier.

It's like trying to wrap my head around a CD/DVD going bad because the written portion somehow became corrupt. It doesn't work in my head how that can happen, but plenty of evidence on here suggests otherwise.
Ah, but the substrate can go bad and change the "pits" that make up the data. Burned discs with a purple color are usually have an organic substrate that can deteriorate in the presence of UV light / sunlight. I have accidentally left discs near a window and you can see the change in color. Once I had a gem clip on a disc that left a ghost image after a few weeks.

(holding up a Dr Pepper)

Here's to a reflash fixing the problem!
 
Okay, I've got a number using Torque Pro on an Android phone communicating via Bluetooth to the OBD2 adapter.

It was blistering cold outside as we are down in the 50s and I had to run the defroster since it was a little drizzly. I have a friend with a long, smooth paved drive to his house on a farm that I have used it to diagnose vehicle before. (At least this time his wife couldn't complain about engine noise!) While the driveway was wet but I never spun a tire and traction control never kicked in.

Turns out that my car is truly slower than it feels. Perhaps being so low to the ground versus my truck gave me the impression that it was quicker than it really is.

I did three runs to 60 mph: 12.389, 12.667 and 12.501 seconds.

Soooo, that seems in line with the other numbers.

However one interesting thing did occur. I did see 61kW pop up on the display and stay there for a couple of seconds. So "59" itself isn't a hard point. Maybe because I had the climate control system on because doesn't that get added into the power numbers?

Anyhow, question answered and another piece of puzzle is found. Now where to put it!?
If somebody tried to EFILive/HPTuners flash it and failed or used a similar tool, they could have accidentally limited output. You would see no check engine lights, nothing. You will need the dealer tool to reflash the Hybrid Control and ECM back to stock if you cannot locate the guy who tuned it, since most of them lock the tunes onto your computer.

Or your floor mat is blocking the accelerator from full actuation.
 
Just for fun, did you try sport mode and see if you get any different max number?
That would rule out accelerator input sensor/calibration vs a software limit on the drive inverter output, for example.

If it was a floor mat, this would show as a different value as 90% down in sport is different from 90% down in normal. (I don't believe it's floor mat - my bet is on software - one of the systems is holding back)
 
I missed that bit, read too quickly and just noted drive or low :)

So yes, confirms nothing about floor mats or accelerator position sensor. It's software.
 
Think of your Gen 1 Volt as an electric car that can run on electricity from the battery or electricity from the generator.

When fueled by the battery in CD mode, it seems to work ok.

In CS mode, if the generator output is below programmed levels, the primary motor will need to draw power from the battery more frequently to maintain performance, and the generator will need to run for longer periods of time to maintain the battery state of charge. This would also cause Reduced Propulsion Power mode to occur sooner. Greater demand for generator output requires more gas consumption, and the "gas mileage" will suffer.

If in normal operations the engine/generator is not running continuously except under maximum demand conditions (i.e., it is being turned on and off to keep use of gas to a minimum), perhaps the system adjusted the timing of the "on/off" cycle to compensate for the gas quality on the one occasion when the tank was filled with "regular" gas. In this instance, it actually resulted in more efficient timing, which then increased the actual gas mileage.

Don’t know what type of testing could confirm that generator output is within spec and the engine/MGA clutch is fully functional. One would think that if reduced generator output was caused by internal degradation in the generator itself, the problem would also manifest itself in the opposite direction, lowering ev performance when MGA is acting as a motor while driving in two-motor ev mode.
 
I think I see where you are going with that wordptom. However, the OP has stated that reduced power is also demonstrated with a fully charged battery. Something that SHOULD NEVER happen except I understand only when "engine not available, please add fuel" is present. Everything the OP has stated seems to indicate a definite software issue, or possible hardware failure of some sort without the presence of a MIL. It almost seems to me that either full power is not available to the MG for whatever reason, or perhaps only 2 of the AC phases are actually making it into the MGB/A which would explain the lower performance as well as the poor MM buffer build time. The lack of codes or MIL seems to indicate the system isn't aware of a problem though.
 
Re-reading this thread stirred a thought... I wonder if the previous owner "rode the brakes." This could have led to the need to replace the brake pads... and could "riding the brakes" eventually degrade the regen/friction brake blending programming?

Another thought... when coasting at a reasonable speed, shifting from D to L should produce a noticeable increase in regen. What happens if, when coasting in D, the OP places a light pressure on the brake pedal? Putting a light pressure on the brake pedal should increase the regen (without applying any friction braking), unless some misadjustment instructs the system to decrease the regen because the (friction) brakes are being applied.
 
I think that wordptom has given a good reason for the reduced fuel efficiency – the ICE running longer at lower RPMs to keep up with the demands – and not succeeding where it properly should.

I’m not sure that “rode the brakes” could occur in the Volt, that is, pushing slightly on the pedal causing the pads to constantly be in contact with the rotors. Regeneration would occur, but not physical pad braking. Riding the brakes could have been the reason for the less than stellar overall ICE mileage, but the OP isn’t doing that, I’m sure, and he is getting worse efficiency figures for the ICE. It also bothers me that the car and gas pump figures don’t agree.

I think we may be in agreement that most likely the software is not right and a re-flash is necessary.

I wish that Customer Care would step in and offer help to the OP. Knowing that a representative of GM is concerned about this problem might make the dealer more inclined to resolve the issue correctly the first time, and not give the OP grief.
 
Discussion starter · #60 ·
Re-reading this thread stirred a thought... I wonder if the previous owner "rode the brakes." This could have led to the need to replace the brake pads... and could "riding the brakes" eventually degrade the regen/friction brake blending programming?

Another thought... when coasting at a reasonable speed, shifting from D to L should produce a noticeable increase in regen. What happens if, when coasting in D, the OP places a light pressure on the brake pedal? Putting a light pressure on the brake pedal should increase the regen (without applying any friction braking), unless some misadjustment instructs the system to decrease the regen because the (friction) brakes are being applied.
Let's say I get up to 55 mph, nice weather, climate control system off, level ground, sufficient battery in the CD mode:



If I left off in D, power usage drops to 0.5 to 1.0 kW with the bar graph showing just a little bit of yellow.

If I then press on the brakes ever so slightly, I feel a "grab" and the vehicle begins to slow. The power meter will not show any change.

If I press on the brakes firmly, I feel the same "grab" and the vehicle decelerates more quickly. I do not have a ratio for this, but I'd say somewhere about half the time the power meter will continue to show 0.5 to 1.0 kW in the yellow but I have seen it drop into the -20 kW area.



If I drop to L, the power meter now shows green and typically is showing about -15 kW but I have been watching it more and have seen it get a bit higher.

If I then press on the brakes ever so slightly, I feel a "grab" and the vehicle begins to slow. The power meter will not show any change.

If I press on the brakes firmly, I feel the same "grab" and the vehicle decelerates more quickly and the amount of regen will increase but I've not been able to make it show -50 kW or better. The -20s are easy and will frequently enough see it reach into the -30s.


I've been watching the meter more over the past week or so. Before, I just enjoyed driving it. Heck, the other day I did 102 EV miles, obviously keeping it charged during the day, although, sadly, it did consume 0.17 gallons of dino juice (according to the energy usage monitor.)


BTW, my appointment with the dealer has been moved to THIS Tuesday, a week sooner than originally scheduled. I just finished giving the car and wash, wax and conditioned the leather. Oh, and I finally removed the protective "to be removed by the dealer" films from the floor.

Oh, and I today discovered the car does not have any floor mats. I thought they were under the film. We can definitely rule out the floor mats!
 
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