austinholloman

If I don't have my tranny in "W" mode, it's stick in third.... Any ideas? Please god don't tell me I need a new one. It's runs fine in "W" but acts really weird in "S" mode.....

w202mylove

Nothing wrong in s it changes gear at red line not before that.

503C43 ////AMG

Did you try the ECU reset (or TCU reset, whatever you call it) ?

I know there is a micro switch that controls the switch from W to S, it is connected to the electronic gear recognition switch but I am unsure if you could replace it by it self. The whole unit (electronic gear recognition switch) is around $100 from the dealership.

I would try the reset first as it won't cost you anything.

austinholloman

How do you reset it?

importfan21

Sounds like you have my problem, as I have yet to fix it (except mine does it in W and S mode).

I've done:

• Filter/fluid/gasket change (and adapter plugs too since they were leaking)
• TCU reset

My problem is temperature related, as it won't shift out until the engine warms up (~10 min/miles).

TCU reset instructions:
1.Turn key to position 2 (on position)
2.Floor (hold) gas pedal for 5 seconds. Turn key to position 0 (off). Don’t remove key. Release gas pedal. Don’t open doors, windows, etc.
3.Wait 2-3 minutes for computer to reset. Start car and drive aggressively for approx. 10 miles. The computer will 'tailor' itself for a more aggressive performance.

Let me know if you find a solution/have similar symptoms like me.

503C43 ////AMG

I can't remember, do you have to hit the kick down switch or not?

importfan21

Yes, you have to hit it.

justinwrock

Try "jockey shifting" it... (Manually upshift through the gears starting in first.)



My C is driven very aggressively, and will hold all of its gears till redline if I leave it in drive.

austinholloman

None of this helped. The only way it will shift like it use to is if I use winter mode... Pissed.

importfan21

You changed the ATF [already]?

Try letting your engine warm up a bit (like it's wintertime) then go out and see if it gets stuck. Mine's temp related but I'm not sure why or what.


Does yours ever shift out of 3rd at all?

austinholloman

I think mine is temp related also.... If I let it warn up it's fine.

importfan21

Well it's good (not really good, but you know) that you have the same problem I do. Only things I could think that are related to temp is the ATF fluid and the cats. I've changed the fluid, so the only thing left for me to try is to replace the cats.


Wish I knew what the problem was...

Frank Castle

ATF level is full? I know when mine dipped low it acted up.

austinholloman

Mine ended up being because I was running in my spare?? It's was in the front pass side. It's a 17 and the rest are 18... Major fail. Lol

DRBC43AMG

Jeez man, how can that happen

importfan21

Now that you mentioned that, I think that was the cause of my problem too. I had to throw the spare on front driver's side when I got a flat, but the spare is the same size as the fronts, correct? Then when I got my new wheels on (no more spare on), that happened right when the heat wave hit, and my problem went away.

WEIRD.

Benzonline

Phew! All cause of a spare! Don't you just love these cars Life is Good with a C43

KJI3jflarryfe93

could it be because of the wheel geometry was wrong?
and the trans burned or something?

importfan21

If it were on the rear axle, I'd say maybe. Even then, maybe it'd affect the differential, not the transmission. Also, I was running stock wheels front/rear when I had my problem.

But the front axle?! Seriously?! This was the most frustrating troubleshooting I've ever had to do!

DRBC43AMG

ABS perhaps?

MarcusF

All four wheels are used to determine vehicle speed and the TCU knows vehicle speed. If one wheel is rolling at a different speed than the others, it seems likely the TCU would know that something is wrong.

503C43 ////AMG

Marcus is correct as usual... If you replace your front pads or rotors you can see the speed sensor connected to both of the front hubs.

The one thing I don't get is why don't we see issues when doing a burn out or power slide around a corner? The rear wheels are traveling MUCH faster than the fronts and I would expect to see a similar issue when this occurs

KJI3jflarryfe93

when often doing burn outs, you stress the transmission and will eventually burn clutchpacks also destroying the rear axle

DRBC43AMG

Bad Boy attitude

austinholloman

My car is running like a dream... Time to start 5.4l shopping for a rainy day.....