GM Volt Forum banner

1 - 20 of 24 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
Why does my 2014 Volt not go into 'SC' mode? When the 'EV' miles reach '0' the ICE comes on and instantly goes to a high speed charge mode (not seen or referred to anywhere). The battery charge display is also all grayed out.
 

·
Registered
Joined
·
209 Posts
Normal. The switch to "high speed" generator mode is to bring you back to a safe SC mode. The motor takes time to warm up, during that time, you may have dip too much into the reserve so the high speed generator mode is appropriate.
 

·
Administrator
Joined
·
19,980 Posts
It's working hard to build up a buffer in the depleted battery while at the same time powering the drive-train. Once the buffer is built, it should settle down to maintaining it.
 

·
Registered
Joined
·
2,359 Posts
I live in "rolling hills" and mountain territory. Same thing happens to me as well if I run out on an uphill segment and then the REX has to play "catch up" with the battery charge.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #5
It used to show several green blocks when the 'EV' miles reached '0'. It now never shows a reserve unless the ICE charges it but when that is happening I get only 20 mph.
 

·
Registered
Joined
·
2,359 Posts
It used to show several green blocks when the 'EV' miles reached '0'. It now never shows a reserve unless the ICE charges it but when that is happening I get only 20 mph.
Well that doesn't sound normal/correct. If you have a dealer nearby you might want to get that checked.
 

·
Registered
Joined
·
5,782 Posts
It's been in the shop now for 8 days and they say it is normal because there is no problem codes. by the way that should be 20 mpg. sorry.
In this case, one letter makes a huge difference. An 'instant' 20mpg is nothing to worry about if it eventually settles down to 35+mpg.

Don't worry about mpg unless three-tanks-full of gas is giving less than EPA rating. Then check driving conditions to see if they match EPA test cycle. If driving conditions are divergent, then, mpg will be divergent (in either direction).
 

·
Registered
Joined
·
12 Posts
Discussion Starter #9
I'm not really concerned about the 20 mpg but I am concerned that I never have any green bars after the EV miles reach zero.
 

·
Registered
Joined
·
45 Posts
That's normal. You have used up all the battery and it will stay gray on the screen even as it builds a little and then settles down to not running as fast. My 2014 has always been as you describe. Why would it show any green in the battery when it is fully depleted?
 

·
Registered
Joined
·
1,313 Posts
It should never show green bars when the charge has been depleted... either you are mis-remembering or the car used to have a software bug/glitch and it somehow fixed itself (I have seen a few software gremlins in my Volt now and then, but not one like that).

Alternatively... there are two different settings on how it displays ICE vs battery on the driver display, maybe you were used to one and it got switched to the other (I think mine switched itself once) so it looks weird to you now? This is set with the knob/buttons to the left of the steering wheel.

FYI, we call it CS (Charge Sustaining) mode, not SC.
 

·
Registered
Joined
·
3,634 Posts
Well that doesn't sound normal/correct. If you have a dealer nearby you might want to get that checked.

Agreed, that's the thing that sounds wrong to me. Other than ERDTT or maintenance, why would one expect the engine to start up when there was still battery charge available?
 

·
Registered
Joined
·
3,192 Posts
I'm not really concerned about the 20 mpg but I am concerned that I never have any green bars after the EV miles reach zero.
As others have stated there should be no green bars left when you reach 0 EV miles. The green bars are not representative of battery state of charge. The green bars are representative of usable energy for EV operation.
 

·
Registered
Joined
·
3,396 Posts
As others have stated there should be no green bars left when you reach 0 EV miles. The green bars are not representative of battery state of charge. The green bars are representative of usable energy for EV operation.
Green bars can reappear with regen or SOC recalculation after CS begins, but you'll still remain in CS mode.
Under normal operation, it should show 0 bars as the goal is to not charge too much, but to maintain a narrow buffer.
Not sure if that's what OP is talking about.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #15 (Edited)
I thank all of you for your feedback but why is the battery suddenly fully depleted when it hasn't been for 18 months driving the same way. Maybe I wasn't clear. I am talking about the battery display on the center console.
 

·
Administrator
Joined
·
19,980 Posts
I thank all of you for your feedback but why is the battery suddenly fully depleted when it hasn't been for 18 months driving the same way. Maybe I wasn't clear. I am talking about the battery display on the center console.
It sounds like you are ladling out details in piecemeal. We can only go on what you are telling us.

So it seems like we need to have you give us all the details: How many miles did you travel on the battery before it was depleted? What were the driving conditions (city? Highway? Speed? A/C? Tire pressure?)?
 

·
Registered
Joined
·
12 Posts
Discussion Starter #17
OK, I'm sorry some things sounded piece meal. But first when I refer to the 'EV Miles' this would be on the drivers display and when I refer to the 'Battery Charge' Display' this would be the battery display on the center console. I did have 2 typos when I typed 'SC' instead of 'CS' and 'mph' instead of 'mpg'. Those things happen. This could be a long story but here goes.

For 18 months when the 'EV Miles' reached '0' the ICE would come on in 'CS' mode and the 'Battery Display' would still have 3 or 4 blocks still green. This month I made the same 1300 mile trip as I did the year before. I was driving 75 mph with the ambient temp above 100 degrees, tire pressure at 38 lbs., and a/c on. All went well until I reached my destination when the 'Battery Display' went all grey and the ICE went to a very high rpm which put some charge back in the battery display. Ever since then after a full complete charge the 'EV Miles' are normal (around 39) but when it reaches '0' the 'Battery Display' is all grey again and the ICE again goes into a high rpm mode instead of the normal 'CS' mode. All this trip I was driving in 'Normal' mode.

I thank you for your patience and since it is now very late I will check back tomorrow.
 

·
Registered
Joined
·
1,992 Posts
For 18 months when the 'EV Miles' reached '0' the ICE would come on in 'CS' mode and the 'Battery Display' would still have 3 or 4 blocks still green.
This is not normal unless you are possibly referring to the Center Stack display. The driver display will not do this. The Center Stack or Console Display has a Power Flow screen. Depending on what is going on this can change. See pages 5-28 and 5-29 of the manual for various scenarios. However, this is different than the driver display.

All went well until I reached my destination when the 'Battery Display' went all grey and the ICE went to a very high rpm which put some charge back in the battery display. Ever since then after a full complete charge the 'EV Miles' are normal (around 39) but when it reaches '0' the 'Battery Display' is all grey again and the ICE again goes into a high rpm mode instead of the normal 'CS' mode. All this trip I was driving in 'Normal' mode.
And this is normal. The engine will rev high for a while especially at 75 mph. Eventually if finds a point at which the RPMs are where they need to be.
 

·
Registered
Joined
·
6,661 Posts
Where are you located? Maybe a few local Volt buddies could arrange to meet you and take a look at your Volt and situation and compare yours to theirs. That's how Corvette owners deal with odd situations that can't easily be explained in text messages.
 

·
Registered
Joined
·
777 Posts
Where are you located? Maybe a few local Volt buddies could arrange to meet you and take a look at your Volt and situation and compare yours to theirs. That's how Corvette owners deal with odd situations that can't easily be explained in text messages.
The OP's profile says "United States" for location. I live there too, we must be neighbors! I'd be glad to go for a ride with the OP and explain all and recommend a good GM service department if needed.
 
1 - 20 of 24 Posts
Top