Traction Control (sport mode) cuts power in WOT second gear upshift
08-02-2017, 03:36 PM
#26
MBWorld Fanatic!
Had something similar happen again (more than once). This time traction was off. Was steady at 4k rpm in second gear and floored it. Car jerks forward, and then stalls for half a second, and then picks up again. No CEL. Haven't checked codes. Should I just keep driving it and ignore this since it doesnt happen all the time and car hasnt complained yet? Should I just ease into the throttle instead of slamming it from a steady throttle position?
Anyone else experienced this? I think it may not have been TCS that cut the power when I had it in sport mode. Since in both situations (sport mode vs off), the acceleration-pause-acceleration is around 4-5k in second gear. Doesnt seem to happen in first gear.
Anyone else experienced this? I think it may not have been TCS that cut the power when I had it in sport mode. Since in both situations (sport mode vs off), the acceleration-pause-acceleration is around 4-5k in second gear. Doesnt seem to happen in first gear.
Try doing all manual shifts in M and see if you can reproduce it.
I am beginning to suspect you might have a valved in the T hanging but not long enough to set off an alarm.
08-02-2017, 03:38 PM
#27
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Join Date: May 2017
Location: London, Ont
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2012 C63 AMG
Had something similar happen again (more than once). This time traction was off. Was steady at 4k rpm in second gear and floored it. Car jerks forward, and then stalls for half a second, and then picks up again. No CEL. Haven't checked codes. Should I just keep driving it and ignore this since it doesnt happen all the time and car hasnt complained yet? Should I just ease into the throttle instead of slamming it from a steady throttle position?
Anyone else experienced this? I think it may not have been TCS that cut the power when I had it in sport mode. Since in both situations (sport mode vs off), the acceleration-pause-acceleration is around 4-5k in second gear. Doesnt seem to happen in first gear.
Anyone else experienced this? I think it may not have been TCS that cut the power when I had it in sport mode. Since in both situations (sport mode vs off), the acceleration-pause-acceleration is around 4-5k in second gear. Doesnt seem to happen in first gear.
I will let some others chime in here, i have not driven the car with traction off always have it on.
Is there an option for you to take one out for a test drive from a dealer and see if it does it on that one as well?
08-02-2017, 03:41 PM
#28
Super Member
Thread Starter
https://mbworld.org/forums/w211-amg/...eleration.html
What they describe is very similar to mine. A lot of posters even mentioned P20D4 "The load limit is active". I think the posters in there concluded that it was load limits in the ECU and TCU.
I only noticed this happening after installing the EC v7 beta tune. Never happened on V6. Hopefully the v7 just makes too much power?
I have not experienced this with my car, i can gun it in Sport + at any rpm and it does not hesitate just goes, especially in S+.
I will let some others chime in here, i have not driven the car with traction off always have it on.
Is there an option for you to take one out for a test drive from a dealer and see if it does it on that one as well?
I will let some others chime in here, i have not driven the car with traction off always have it on.
Is there an option for you to take one out for a test drive from a dealer and see if it does it on that one as well?
Actually, come to think of it, I think this is totally seperate from any TCS related issue. I remember just yesterday that I was doing a first gear pull with TCS on, and the TCS lights lit up all the way to third gear, with no power "cutting", just power limiting. TCS did not fully close throttle. It just limited the throttle and my car kept pulling, albeit slower than with TCS off and letting the wheels chirp.
The more I think about it, the more it makes sense that it is an ECU/TCU load limiter that closes throttle bodies upon a certain threshold being exceeded, which V7 is doing now. I haven't experienced the hesitation/jerk with TCS on. It only happened once in sport mode, and seems to be more common in manual mode. And it only happens on very violent and quick smashing of the throttle from high RPMs.
Last edited by NotABaller; 08-02-2017 at 03:49 PM.
08-02-2017, 05:03 PM
#29
Member
Actually, come to think of it, I think this is totally seperate from any TCS related issue. I remember just yesterday that I was doing a first gear pull with TCS on, and the TCS lights lit up all the way to third gear, with no power "cutting", just power limiting. TCS did not fully close throttle. It just limited the throttle and my car kept pulling, albeit slower than with TCS off and letting the wheels chirp.
The more I think about it, the more it makes sense that it is an ECU/TCU load limiter that closes throttle bodies upon a certain threshold being exceeded, which V7 is doing now. I haven't experienced the hesitation/jerk with TCS on. It only happened once in sport mode, and seems to be more common in manual mode. And it only happens on very violent and quick smashing of the throttle from high RPMs.
Still what you're describing sounds a lot like the transmission is having a very rough shift. I had this when I delayed getting my fluid changed and the valve body was probably partially clogged on the lower gears and possibly engaging more than one while shifting. When was the last time you had your fluid changed?
08-02-2017, 05:14 PM
#30
Super Member
Thread Starter
So from what I remember reading about the cars traction control is in normal its the rear brakes that kick in when the car senses a loss in traction. In sport the car upshifts during a loss of traction and doesn't really cut the throttle. In off I hear some form of traction control is still on but I never play with that since I'm not a professional stunt man.
Still what you're describing sounds a lot like the transmission is having a very rough shift. I had this when I delayed getting my fluid changed and the valve body was probably partially clogged on the lower gears and possibly engaging more than one while shifting. When was the last time you had your fluid changed?
Still what you're describing sounds a lot like the transmission is having a very rough shift. I had this when I delayed getting my fluid changed and the valve body was probably partially clogged on the lower gears and possibly engaging more than one while shifting. When was the last time you had your fluid changed?
08-02-2017, 10:37 PM
#31
Senior Member
Had something similar happen again (more than once). This time traction was off. Was steady at 4k rpm in second gear and floored it. Car jerks forward, and then stalls for half a second, and then picks up again. No CEL. Haven't checked codes. Should I just keep driving it and ignore this since it doesnt happen all the time and car hasnt complained yet? Should I just ease into the throttle instead of slamming it from a steady throttle position?
Anyone else experienced this? I think it may not have been TCS that cut the power when I had it in sport mode. Since in both situations (sport mode vs off), the acceleration-pause-acceleration is around 4-5k in second gear. Doesnt seem to happen in first gear.
Anyone else experienced this? I think it may not have been TCS that cut the power when I had it in sport mode. Since in both situations (sport mode vs off), the acceleration-pause-acceleration is around 4-5k in second gear. Doesnt seem to happen in first gear.
This isn't the first post I've seen about throttle issues in relations to a tune.
Last edited by SuckaGDog; 08-02-2017 at 10:43 PM.
08-02-2017, 10:41 PM
#32
Member
This has happened to me exactly about 3-4 times so far. But mine goes into Inoperable Mode. I shutoff the car, turn back on, its all good. I don't get it either...sometimes it lets me do a burnout, but then doesn't let me pull hard out of 2nd? This is M mode, Sport Mode , and Trac off
