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Discussion Starter #1
My new Volt (1900 miles) is in the shop with a braking issue. On the 4th it asserted the check engine and ABS error lights. The dealer has opened a case with GM engineering and they are trying to determine the problem. The error has to do with hydraulic pressure during blended braking (the Volt combines electrical braking with conventional hydraulic braking according to an algorithm). GM is having them run through a series of tests but they haven't been able to get the fault to reassert itself yet, it's possible that I've encountered a bug. My suspicion is that it's related to the L mode. I've been using regular drive mode since I got the car in May but on the way home on the 4th I decided to try L. In case anyone doesn't know L is not LOW as it would be in a car with a transmission, it's just Drive with stronger regenerative braking. When you are in L you can mostly do single peddle driving because taking your foot off of the accelerator engages the regenerative braking. It was after I had driven in L mode that I noticed the fault lights and the Service message. It could be a coincidence but it certainly possible that it could be related.

Has anyone else with a 2017 Volt driven extensively in L mode? Has anyone else had any braking fault codes?
 

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2017 Handles abt the same as my 2014 to me, a little heavier and tighter steering feel to my impression. Always drive in L since leaving the dealer lot, no issues yet.
 

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A loss of traction while braking in 'L' mode can cause some strange reactions in the braking and traction/stability control systems, and sometimes a perceived loss of braking. It's not unusual, and as far as I know, has never led to any serious consequences.

I never use 'L' any more, except at times in heavy traffic or to hold speed on a long downhill run. I prefer one pedal for go and one for slow. You still get the equivalent regeneration by using the brake pedal.
 

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Always drive in L. No issues. People have on occasion suggested driving in L is a factor in one failure or another but so far this hasn't been the case.
 

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A loss of traction while braking in 'L' mode can cause some strange reactions in the braking and traction/stability control systems, and sometimes a perceived loss of braking. It's not unusual, and as far as I know, has never led to any serious consequences.

I never use 'L' any more, except at times in heavy traffic or to hold speed on a long downhill run. I prefer one pedal for go and one for slow. You still get the equivalent regeneration by using the brake pedal.
The only other time I've used L was in the winter with slightly worn tire on packed snow where any tap of the brakes cause anti brake locks, I mean, antilock brakes to kick in. But that was during snowageddon 2 over a year ago, last near, essentially 1 big snowfall and not much else to report. I have snow tires now, yet they were on the car less than 24 hours.

I'm undecided on whether that was the best or worst $600 spent on tires.
 

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My new Volt (1900 miles) is in the shop with a braking issue. On the 4th it asserted the check engine and ABS error lights. The dealer has opened a case with GM engineering and they are trying to determine the problem. The error has to do with hydraulic pressure during blended braking (the Volt combines electrical braking with conventional hydraulic braking according to an algorithm). GM is having them run through a series of tests but they haven't been able to get the fault to reassert itself yet, it's possible that I've encountered a bug. My suspicion is that it's related to the L mode. I've been using regular drive mode since I got the car in May but on the way home on the 4th I decided to try L. In case anyone doesn't know L is not LOW as it would be in a car with a transmission, it's just Drive with stronger regenerative braking. When you are in L you can mostly do single peddle driving because taking your foot off of the accelerator engages the regenerative braking. It was after I had driven in L mode that I noticed the fault lights and the Service message. It could be a coincidence but it certainly possible that it could be related.

Has anyone else with a 2017 Volt driven extensively in L mode? Has anyone else had any braking fault codes?
I haven't read about anyone else throwing a code from braking. Did you ever feel anything abnormal?
Plenty of Gen2 (and Gen1) drivers drive exclusively in L and report no issues. Good luck and report back what they determine.
 

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I haven't read about anyone else throwing a code from braking. Did you ever feel anything abnormal?
Plenty of Gen2 (and Gen1) drivers drive exclusively in L and report no issues. Good luck and report back what they determine.
And a few, like me, and possibly the OP, have had issues. That's why I mentioned it, but that's not why I don't use 'L' - it's just a matter of personal preference.
 

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Discussion Starter #9
Has anyone else experienced a fault code caused by the L mode? I didn't have any problems breaking and the L mode operated as advertised, i.e. taking my foot off of the accelerator caused the car to slow. My issues is that the diagnostic system detected a fault in hte braking and asserted a error code.
 

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Has anyone else experienced a fault code caused by the L mode? I didn't have any problems breaking and the L mode operated as advertised, i.e. taking my foot off of the accelerator caused the car to slow. My issues is that the diagnostic system detected a fault in hte braking and asserted a error code.
In my case, slowing and braking in 'L', over wet railway tracks, lit up the MIL, traction, and stability control lights and the pedal went most of the way to the floor. I still had braking, but with a few more inches of empty pedal. I went immediately back to the dealer, which I had just left. After shutting down and restarting the problem disappeared. The service manager drove it and found no faults but I don't know for sure if he checked for codes.

Something similar happened one more time, and again it went away after a shutdown and restart.

There are other threads on here about comparable experiences. Mostly they devolved into arguments over the merits or drawbacks of 'L' mode, which I'd be happy to avoid.
 

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I drove exclusively in L on our leased 2013 for 3 years, I have now driven exclusively in L with our 2017 for 4 month so far no issues
 

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Has anyone else experienced a fault code caused by the L mode? I didn't have any problems breaking and the L mode operated as advertised, i.e. taking my foot off of the accelerator caused the car to slow. My issues is that the diagnostic system detected a fault in hte braking and asserted a error code.
What is the DTC being retrieved???
WOT
 

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And a few, like me, and possibly the OP, have had issues. That's why I mentioned it, but that's not why I don't use 'L' - it's just a matter of personal preference.
What I was talking about and what the OP was asking about is throwing codes as a result of braking while in L, not just loss of traction during braking.
 

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Discussion Starter #15
Braking performance was fine, and L worked as advertised. The issue was that I got fault codes, it's possible that the bug is in the diagnostic code as opposed to a real braking problem. I'm going to do a mix of D and L driving over the summer and I'll see if the codes reappear.
 

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What I was talking about and what the OP was asking about is throwing codes as a result of braking while in L, not just loss of traction during braking.
Understood, and what I was saying was that I had issues, and probably codes, while braking in 'L', and never in 'D', and that I thought loss of traction was a contributing factor. I'm not trying to say the two situations are identical. The OP did not say whether or not he lost traction. Others have had similar issues just slowing in 'L' on a bumpy surface.
 

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Discussion Starter #17
I didn't have any loss of traction, it was a dry summer day. Most of my driving was on highways so I was taking off ramps in L mode which involves turning and braking at the same time.
 
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