mikekuriger

I'm driving home today and after about 5 minutes I noticed that my car was stuck in 3rd gear. I gently drove home a couple miles and shut off the engine. This has happened a couple times before (over the last 3 years) and an engine restart always fixed the issue. This time though it's not going away. Got a CE light, code P0715. Tranny wont shift out of first (or possibly 2nd). I can use reverse fine though.

Has anyone opened up their tranny to fix this sensor? I'd like to do the repair myself so that I'm familiar with the tranny internals. Any help or advise would be great.

thanks,
Mike

saer1one

The code Is most likely a speed sensor which Is located in the conductor plate. You should try searching on DIY's. I've run into a couple of them with pictures included. GL

Found this thread from Benzworld.org hopes this helps..
http://www.benzworld.org/forums/w140...tor-plate.html

mikekuriger

Thanks for the link. I think this would be a piece of cake if I had a lift.

mikekuriger

I went to the dealer and purchased the parts needed to fix this tranny issue.

electronics kit (part number 140-270-11-61) - $280 @ dealer, got on ebay for $165
transmission pan gasket (part number 140-271-00-80) - $15.00
Trans Pan Drain Washer (part number 140-271-00-60) - $2.91
Transmission oil filter (part number 140-277-00-95) - $15.97
Lock pin (part number 140-991-00-55) - $2.91
Connector Bushing (part number 203-540-02-53) - $18.20

I'll also be replacing the brown top solenoids with blue tops. Pics will follow.

91RS

I think I want to do the blue tops. I want faster shifts but as long as that doesn't also man rough shifts. Definately take many pictures and give a review of the blues. I've been looking for some sort of DIY on the valve body for a long time, doesn't actually look that bad. I couldn't find whether or not these had check ***** or gaskets/spacers between the valve body and transmission case, etc.

mikekuriger

I completed this repair tonight. It took about 2 hours. I haven't tested it yet because I still need to refill the tranny with fluid. Did it in the garage, not hard at all. I think changing the spark plugs was about 3 times harder. I didn't take a lot of pictures since it was so simple to do, and there are already a lot of good pictures posted.

I replaced that black plastic electric piece, and replaced my brown tops with blue tops. I also noticed that my wiring harness was oily. I replaced the wiring harness bushing as well. Now I just need to put the fluid back in and see if it actually works.

91RS

Wow, if you could do it in 2 hours in the garage it really can't be that hard! Definately let me know what you think about the blue tops. As long as they're not harsh, I'll be ordering them. I gotta find that thread about them again with the part numbers and all. I wonder if I should replace any of the other parts while the valve body is out. I've only got 40k on my car and I'm wanting to say the valve body might have been replaced by the PO under warranty (I really wish they could get me my warranty history, especially since I'm out of warranty).

mrobinso

I have been following this thread with much interest. Can't wait to hear how it runs once you put the fluid in... keep us updated!

mikekuriger

OK, and sorry for the late update.

I finally brought my C55 to the dealer to have the TCU reactivated. I've driven the car about 50 miles on freeway and streets and here are my initial impressions:

1 - street driving in S, it's too jerky. both upshift and downshift is jerky. full throttle shifting is faster than stock, but not harsh at all. feels like it should shift that way stock.
2 - in C mode, it's a little smoother. the 2-1 downshift doesn't happen so that's a little better.
3 - on freeway, downshifts are too fast. the engine doesn't rev up before the downshift happens so it has a noticeable jerk before it takes off. It's not as bad in C mode. If I am in M mode and floor it, then downshift, the engine revs up quicker and the downshift is crisp and power comes on instantly. In S or C mode there is some engine lag. The lag is noticeable with the stick transmission as well, but it's masked by that ultra slow clutch release. There may be some tranny learning going on so I'll have to report back in a few weeks to see if it's better.

What I'd really like to do is get the TCU remapped. I'm trying to find a good vendor for this. If I could get the stock E55 shift behavior in C mode, and the crisp shifting in S mode, AND get the downshifts softened, that would be amazing. If not, I'll live with this.

One thing I did notice is my torque converter lockup is better. Before, on the freeway, I could give it about 2/3 throttle (just enough that it accelerates without downshifting) and the RPM would raise 200 rpm or so due to slip. This behavior is gone. I can put it in M mode and floor it and the RPM doesn't budge - that is until the car actually speeds up. I think this mod will help get more accurate dyno runs.

So, does anyone know of any TCU programmers?

91RS

Eurocharged does a TCU mod. Do you have any ECM tune at all? I'm wondering if some ECM changes could be made to fix the engine lag. I might have to send an e-mail to Eurocharged and see if they have anything to make the blue tops work better.

mikekuriger

Yes, my ECU tune was done by OE Tuning. The lag I speak of is the time it takes the engine to free rev from LOW RPM to HIGH RPM (such as when downshifting) - it's not a lack of response, just that the clutch in the transmission is letting out during a downshift while the motor is still trying to rev up to the higher RPM of the lower gear.

Newzchspy

Mike, speak to Mike (HooleyBoy) and MBH. He's been around this block more than once with the blue tops and knows the issue. I believe that a TCU reprogram will not alleviate the issue. He did his on the old C55 and describes the exact same issue that you describe with the Blue Tops. I think the only way to get it back to "normal" if you will, is go with the old brown tops. You've already repaired the sensor issue, why not just go back to brown tops??

mikekuriger

I'm not 100% sure on all this info, it's just what I've learned from various posts over the years.

The blue tops are needed to increase the line pressure. A TCU reprogram can be used to reduce the pressure for certain operations. What Mike did was attempt to increase the pressure via software, however the brown tops were already maxxed out. Switching to blue tops actually allows the pressure to increase which is what allows the clutches and other components to grab tighter. The E55 has the same valve body but has different programming. For the E55 guys to get the faster shifts, they only need the TCU reprogram since they already have the blue tops. Some C55s also have blue tops stock.

splinter

Installed the blue tops in my C32.
Jerky and abrupt during light throttle shifts with no discernible improvement at WOT. Ditched ‘em shortly thereafter.

Judicious PWM line pressure and TM tweaks worked wonders.


photo credit MJ50

Newzchspy

Explain??? I am looking for this as well for the C55....