[scottf200]

Do you have this applied?

 

[scottf200]

Summary

My goodness there seem to be a plethora of similar recalls for updating the Hybrid Powertrain Control Module 2 (HPMC2), and now to include the Gen 2 Volt!

N202307990, issue date, Feb 04, 2021, for 2016-2018 Volts
N172130460, issue date, June 14, 2018, for 2013 Volts
N172130462, issue date March 29, 2019, for 2013-2015 Volts
N172130462, (updated October 2019 to include 2012 Volts)
N172130461, dated December 2019, for 2011 Volts

...and not to forget the procedure to correct the PPR problems arising from a simple loss of "oomph" in older Gen 1 Volts, Bulletin No. PIC6292C

 

[rbon]

Thank you Scottf200 for your reply. I am not understanding your comment "Do you have this applied?" Would you kindly explicitly explain what you are asking? Sorry for being dense here.\Ron

 

[rbon]

More information: I went back and checked my past service write ups and found this entry for a service performed on my car by the dealer on 4/07/2021"

" Minor recall. Customer Satisfaction Program (N202307990): Increased Customer Notification PEFORMED RECALL. UPDATED HPCM2 USING SPS.WARR CODE: CBYN64113611"

So this seems to say that the dealer performed this software upgrade/fix. What does the fact that this service was performed mean in relation to the issues I am now reporting? Should I still be concerned or because this service update was performed has the issue we are concerned with been resolved for this vehicle? Should I bring the car into the dealer? I definitely do not want to be stuck on Highway 101 with a car w/o propulsion

 

[caronjeff]

If you can’t plug in always use your hold mode or your mountain mode to keep those 3-4 bars of battery charge when the car is sitting unplugged overnight. Peace of mind. If you have propulsion reduced events, Do Not Shut Off the car!! Until the high revving engine subsides and the message goes away. Don’t worry these events seem kinda normal in any older Volt. My 2011 first exhibition of “Propulsion reduced” was about 5 years ago. It now has 192,000 miles and a 12 years old battery. Just baby that battery with plugging in as much as possible and use mountain mode if you can’t.

 

[scottf200]

More information: I went back and checked my past service write ups and found this entry for a service performed on my car by the dealer on 4/07/2021"
" Minor recall. Customer Satisfaction Program (N202307990): Increased Customer Notification PEFORMED RECALL. UPDATED HPCM2 USING SPS.WARR CODE: CBYN64113611"
So this seems to say that the dealer performed this software upgrade/fix. What does the fact that this service was performed mean in relation to the issues I am now reporting? Should I still be concerned or because this service update was performed has the issue we are concerned with been resolved for this vehicle? Should I bring the car into the dealer? I definitely do not want to be stuck on Highway 101 with a car w/o propulsion

I don't know your climate where you live as I would guess that a colder climate older Volt (ie. Gen II) would run into this earlier. There is a range of voltages for the cells that make up the battery and when it hits ~20% SOC (depending on year) the ICE/gas kicks on and maintains the SOC level around 20%-22%.

The trouble with battery degradation is it hit the lower limit of voltage that GM initially considered 'as bad as it would get' and it spits out the Propulsion Power Reduced (PPR) message. Once they realized that they did not set that limit to be high enough to account for degradation then they put out a software 'patch' (fix/change) to raise that limit when the ICE/gas engine would kick on. ie. the "floor" or lower limit. That was the Customer Satisfaction Program change.

The trouble is that older volts (generally first generation 2011-2015) were going lower (kW / voltage) than they thought even with the "fix". Now we are seeing that PPR msg show up. Hence, the recommendation is to use Mountain Mode (MM) to maintain a higher state of charge (SOC / aka voltage of the lowest cells) to avoid the message and worse problems.

Now that was just a stream of consciousness as I need to go eat dinner so it may not be entirely accurate but should give you the jist.

My first results that might be of interest from the DashDAQ OBD scanner, I eyeballed the transitions of each battery bar. The DashDAQ has at least two signals for battery level in the Volt extension driver, one for battery level % and one for the battery gauge %. The gauge turns out to map directly to the battery bars on the display, with each bar ticking off every 10% of the signal range (at least it did for the transactions I happened to watch - staring at the scanner while driving being a bad idea I haven't watched to confirm the entire series).

Here's how it maps between the gauge display and the actual battery SOC (or at least I think the VICM term is SOC).

Battery Gauge  Gauge %     Battery %
10 bars        91%-100%    81%-86.5%
9 bars         81%-90%     74.4%-81%
8 bars         71%-80%     68%-74.4%
7 bars         61%-70%     61.5%-68%
6 bars         51%-60%     55.3%-61.5%
5 bars         41%-50%     48.7%-55.2%
4 bars         31%-40%     42.1%-48.7%
3 bars         21%-30%     35.6%-42.1%
2 bars         11%-20%     29.3%-35.5%
1 bar           1%-10%     22.7%-29.3%
0 bars          0%-1%      20%-22.7%

The ICE comes on around 20% SOC, and the CS SOC is around 22%. So the ICE runs a bit to bring the SOC back up from 20%ish to 22%ish. This somewhat confirms some of what we've heard about the battery and battery SOC.

I've not yet checked out MM SOC.

The unit can report kW for the battery and each motor, RPMs for each motor and the ICE, and the amount of torque each is generating (with MG-A generating negative torque in CS mode). There's WAY too much data there for me to boil down in a hurry, but suffice it to say the Volt appears to have some tricks up its sleeves as regards how it uses the different units.

RIP Rusty.

 

[rbon]

Thanks for your reply caronjeff. After 6 years with this car, this is the first time I have seen this message.

 

[rbon]

Thank you Scottf200 for the further explanation.

 

[scottf200]

Additional detail via: https://static.nhtsa.gov/odi/tsbs/2013/SB-10063422-2273.pdf

Condition/Concern
A common DIC message seen by customers driving in the mountains is “Propulsion Power is Reduced.” It is
recommended that customers enter Mountain Mode on the Volt when the vehicle has a full charge if their travel plans
involve mountainous driving before the next charge event. This message may appear while severe highway grades,
even in Mountain Mode, such as driving on Interstate 70 in Colorado. This is considered normal operation.

It is possible that this message could appear in Normal or Sport mode in non-mountainous terrain, typically with
aggressive driving. When this message appears with aggressive driving, the battery reserve has been depleted.

This message may also appear on startup if the battery is at or below -15 degrees C (5 degrees F), possibly from the
vehicle sitting outside unplugged in the winter. This will be accompanied by higher engine speeds to compensate for
the low battery power.

Important: This message comes on any time the battery is reporting less than 35kW of power available for any
reason. This message will NOT require service by a dealer unless the Propulsion Power Reduced message is
accompanied by a Malfunction Indicator Light (Check Engine Light).

 

[Off Oil]

To add, if your engine is still running when you park, and you arn't going to plug in, wait for the engine to turn off before turning off the car. The engine is still charging the lower end of the battery buffer at that point. Leaving the battery below the minimum threshold when powering off, may result in the PPR when turning it back on. If that occurs, just wait for it to catch up before leaving.

 

[wordptom]

If you can’t plug in always use your hold mode or your mountain mode to keep those 3-4 bars of battery charge when the car is sitting unplugged overnight. Peace of mind. If you have propulsion reduced events, Do Not Shut Off the car!! Until the high revving engine subsides and the message goes away. Don’t worry these events seem kinda normal in any older Volt. My 2011 first exhibition of “Propulsion reduced” was about 5 years ago. It now has 192,000 miles and a 12 years old battery. Just baby that battery with plugging in as much as possible and use mountain mode if you can’t.

Your advice still applies, but remember that the Gen 2 Volt’s Mountain Mode only keeps 2 bars of the battery charge. The Gen 2 Volt can actually use the ICE as a source for acceleration levels of propulsion torque, and in one of the three extended range modes, the ICE operates as the only source for the car’s propulsion.

 

[rbon]

Thanks for your advice wordptom. Re using Mountain Mode or Hold mode, which would you recommend as best for this situation? BTW--I don't live in the mountains

 

[scottf200]

Thanks for your advice wordptom. Re using Mountain Mode or Hold mode, which would you recommend as best for this situation? BTW--I don't live in the mountains

Personally, I would use MM for the sheer simplicity of it. Get in, tap drive mode 3 times without waiting, done.
With hold mode you have to decide at what level (SOC/bars) you want to turn it on at.

 

[hellsop]

With hold mode you have to decide at what level (SOC/bars) you want to turn it on at.

And not forget. Turning on MM can end up being just part of one's normal "starting the car" routine, like:

1. Press brake
2. push blue button
3. release parking brake
4. set MM
5. shift out of park
6. check surroundings
7. release brakeetc.