Please explain Limp Mode

[exile]

I've checked Vfaq, and did a search for "what is limp mode" on this forum and couldn't find anything. It HAS to be explained somewhere on this forum but I can't seem to find it.

If it ISN'T (which I doubt) please explain it here. My A/t is running like crap and I'm starting to think it's in 3rd all of the time. I can't tell.. How do you know your 2g is in limp mode? Will the check engine light be on if it is in limp mode? Will there be codes on my ECU even if there's no light?

Thanks for your help, and if this thread exsists somewhere else please link. Don't bash.

 

[Froyd79]

disconnect your TCU and go for a drive Thats limp mode. Pretty much keeps the trans in 3rd gear until you fix what ails it. It probably gets hard on the trans after a while in limp mode.

 

[92awdgsx]

What it does is, if the Tcu senses something wrong it turns off both shift solenoids and that why it is in third gear. That is a good way to tell the driver something is wrong and needs to be checked out.

 

[Defiant]

It's a courtesy measure one step above Your Ass Is Stranded mode. It's so you can get to a shop, or at least out of that part of town.

 

[exile]

The reason I ask is because.. my car doesn't downshift like it's suppose to at red lights and stop signs and stuff like that. Makes me feel like I'm in third gear ALL the time.

 

[92awdgsx]

Will it work if you shift it manualy? If it does, the pulse generators might need cleaned.

 

[exile]

Well, when I use the L gear and 2nd gear it accelerates AMAZINGLY. The throttle response and spool up is NUTS. When I sit at a red light with it in Drive and accelerate it's HORRIBLE compared to if I would lower it to L and shift up to 2nd then Drive. A REALLY noticable difference.

Should I clean the generators?

 

[napkinthief]

I think my whole tranny is just going bad, if I'm in L and I keep gasing it past 6500 rpms, itell shift to2nd gear, but then after slowing down it wont shift till rpms reach 6500 again, happens if im in L and rev past 6500, in 2 shifting to L or D with gas down

then to fix it i turn off and turn my car back on

but normally, a car would be able to be restarted in N, so I start it in N and I cant grab a gear, car sits or rolls down a hill.



also when i am slowing down using the breaks rpms will drop to 1500, then there will be a delayed zip tie noise (zipping a ziptie or a zipper) then rpms drop to idle, maybe has some relation?


also you notice L and 2 going faster with acceleration is because they keeps the rpms going to the rev limiter, and you gain most speed from the higher end of the rev spectrum

 

[92awdgsx]

Well, when I use the L gear and 2nd gear it accelerates AMAZINGLY. The throttle response and spool up is NUTS. When I sit at a red light with it in Drive and accelerate it's HORRIBLE compared to if I would lower it to L and shift up to 2nd then Drive. A REALLY noticable difference.

Should I clean the generators?

It sounds like the tranny isn't downshifting when you let in drive, like your starting out in a higher gear. Then when you shift it manualy, its does what its suppost to. The generators might need cleaned or replaced. Next time when you start out in drive and it feels really slow, try down shifting manually and see if it down shifts into the right gear.

 

[92awdgsx]

also you notice L and 2 going faster with acceleration is because they keeps the rpms going to the rev limiter, and you gain most speed from the higher end of the rev spectrum

Where the hell do you come up with this stuff. WTF

 

[napkinthief]

you gain more mph from 5500 to 6500 than you do from 1500 to 2500 dont you?

 

[92awdgsx]

Yes it does because it is spooled by then. But how does that explain why from a dead stop it would feel different in drive, than to put it in first gear and shift manually?