[Frommologist]

My 2011 Volt with 89,500 miles ran very rough on the ICE; the engine ignition coil assembly was corroded and needed to be replaced. This was an intermittent problem over about 4 weeks, but the last time it occurred the engine (and thus the car) would barely run. I was a quarter mile from home.
But I have another issue that occurred about 2 times before the coil was replaced and 7 times since. Shortly (0.5-5 miles) after the battery range is 0, I park the car, not plugged in, and when I restart it immediately goes to Reduced Propulsion Power (RPP) mode and the engine revs up to speeds that have me trying to shift gears! This has occurred with off-time of 5 minutes to a few hours. A few times the outside temperature is dropping about 10F while the car is resting. The check engine light is not on. I am not going uphill, may not even be moving. The car is certainly running at about 50% of the normal power. The RRP message is on for about 2-8 miles of driving. After the message turns off the engine is still revving higher than usual and the car is maybe 75% of normal power. 2-8 more miles it is back to normal with a purring engine and 100% power for accelerations. I have not observed this behavior when I drove over 15 miles with the engine running before the rest. The issue happens about a half of the times I restart after running a short time on the engine.
I am guessing that battery pack controlling units are changing their mind about the state of charge of some of the cells in the pack and signals that they need to charged up. I have no idea why the reported state of charge would change when the car is turned off and then back on.
The dealer had no ideas at the time the coil was replaced, and I didn’t push it since they fixed one problem that may have had an effect on the other. I called the Volt Advisor and she had little to offer other than reading about RPP in the manual and offering to help get an appointment at the dealer. The diagnostic fee will be $105, so I thought I would wait and collect more data. Any of you have similar experiences?

 

[caronjeff]

Tell us how the car operates with a charge. You don't indicate where you live, so assuming somewhere in the north, it should obtain full charge after about 10 hours at 120V and should display range of maybe 26-32 miles. If it's a high voltage battery issue symptoms should arise in normal EV operation. What you describe sounds like a very low battery with a car parked outside in very cold conditions, and no ability to charge it?

 

[Chevrolet Customer Svc]

My 2011 Volt with 89,500 miles ran very rough on the ICE; the engine ignition coil assembly was corroded and needed to be replaced. This was an intermittent problem over about 4 weeks, but the last time it occurred the engine (and thus the car) would barely run. I was a quarter mile from home.
But I have another issue that occurred about 2 times before the coil was replaced and 7 times since. Shortly (0.5-5 miles) after the battery range is 0, I park the car, not plugged in, and when I restart it immediately goes to Reduced Propulsion Power (RPP) mode and the engine revs up to speeds that have me trying to shift gears! This has occurred with off-time of 5 minutes to a few hours. A few times the outside temperature is dropping about 10F while the car is resting. The check engine light is not on. I am not going uphill, may not even be moving. The car is certainly running at about 50% of the normal power. The RRP message is on for about 2-8 miles of driving. After the message turns off the engine is still revving higher than usual and the car is maybe 75% of normal power. 2-8 more miles it is back to normal with a purring engine and 100% power for accelerations. I have not observed this behavior when I drove over 15 miles with the engine running before the rest. The issue happens about a half of the times I restart after running a short time on the engine.
I am guessing that battery pack controlling units are changing their mind about the state of charge of some of the cells in the pack and signals that they need to charged up. I have no idea why the reported state of charge would change when the car is turned off and then back on.
The dealer had no ideas at the time the coil was replaced, and I didn’t push it since they fixed one problem that may have had an effect on the other. I called the Volt Advisor and she had little to offer other than reading about RPP in the manual and offering to help get an appointment at the dealer. The diagnostic fee will be $105, so I thought I would wait and collect more data. Any of you have similar experiences?

Good morning Frommologist,

We're very sorry to learn of this intermittent concern with your Volt. We recognize how frustrated you must be, and we truly apologize for the inconvenience you've endured.

We see that you have been in touch with a Volt Advisor, and we'd like to look into your situation further to ensure we're using all available resources. If you're interested, please send us a private message with your VIN, contact information and involved dealer.

We hope to hear from you.

Lauren E.
Chevrolet Customer Care

 

[Frommologist]

I live in Rochester NY. We have had a very warm fall season, these events happened between 35 and 50F. I charge the car daily with a 240V level 2 charge in my garage. This takes about 3.5hours, but I haven’t tried to see if it takes longer now. The battery range may be dropping a bit; when it was new I typically got about 38 miles in the summer and 28 in the winter. This seems more like 35 and 25 now. I drive 65-70mph on my 15mile each way commute and am not overly concerned about spending watts on acceleration. I have recorded the range nearly daily for 5.5 years. I did some regression analysis of the data including tire type, hours of daylight, rain, outside temperature and do see that large swing between summer and winter but none of the other factor were significant. Seems odd, I expected temperature to be more significant than the month. This data did not show a statistically significant change in range per change over 4.5 years. I have not re-analyzed with the last year of data. I also plan to slice the data into summer and winter blocks and look for differences year to year, or something like that.
I do suspect my current problem may be a weak cell or two that somehow keeps up with its neighbors until the current flow is stopped. Then when the system re-initialized the controller sees that cell as way too low… or something like that.

 

[MrEnergyCzar]

I wonder if the battery thermal management system isn't properly heating the battery.

 

[Jeff N]

I've seen this reduced propulsion issue on my 2011 Volt with 141,000 miles but so far only a couple of times and the last time was a couple of months ago. I regularly run the battery "empty" and drive some miles in charge sustaining during the day. I'm wondering if older battery packs are functioning slightly different than GM expected and some software in a monitoring or control module might need to be refined and updated. I think you are right in that the car is a little confused about the pack state of charge and thus starts up in reduced propulsion mode until it can add more energy to the pack using the gas engine. I noticed after stopping again for an hour and restarting that the reverted to measuring a higher state of charge so that the extra energy added by the reduced propulsion mode now resulted in my starting off with 3 miles of EV driving.

I'm not going to worry about it unless it becomes more frequent.

 

[jbakerjonathan]

Off the wall: has the 12volt battery been replaced during the last 5 or so years?

 

[Frommologist]

J baker: No 12V battery replacement. Nearly nothing replaced, except the ignition coil and some other part (fuse or junction block I recall), long ago. 1 set each of winter & summer tires. A rear brake pad de-laminated from the steel backer, presumably due to water freezing.
Jeff N: Interesting that your range sometimes goes up after a rest. I do sometimes see a bar of charge show up while driving in charge sustaining mode, I expected it was from the battery being warmed up with engine heat. I am a little concerned about the battery performance now since the warranty ends in 10,000 more miles. Propulsion Power reduced mode uses a lot more gas to drive 2 miles than normal charge sustaining driving. Other than that, it is not so bad.

 

[jbakerjonathan]

Frommologist, has your problem been resolved?

The reason I asked about the 12v battery age is that funny things happen when the battery becomes weak. I can't envision a scenario where the battery could cause your problem; however, using a known strong one would rule out this possible cause.

I hope that you have been able to get your problem resolved.

 

[SolarExec]

Frommologist, we are experiencing EXACTLY the same symptoms on our 2011 with ~60k miles on it. It is due in for diagnostics at the dealer here in Houston tomorrow. Please let us know if you had any luck getting this fixed.