decarlod

I tried doing a search for a similar problem but I didn’t find what I was looking for. I have a 2005 Jeep Grand Cherokee with 87K miles on it. I have the problem with the "Service Elect brake system" from time to time. I have read many posts about it being the "brake switch" which I have had replaced many times. Since it really doesn’t prevent me from using the vehicle I live with it.

But now I have a new problem and it seems to be happen with the weather getting cold. When I start up my Jeep in the morning all the error lights on the dash go on. The engine light, the brake light (even when it isn’t on) oil light and so on. None of the meters are working and the odometer is off. If I attempt to use the vehicle it takes off slow like it is in 3rd gear. Then it won’t go past about 35MPH. After about 20 minutes all of this disappears and the transmission works fine. All error lights go off and the vehicle works fine.. until the next cold morning. It being winter now it is happening every morning. To get around this I go out before I get ready for work and turn the truck on. I come out in about a half hour and it is OK.

Anyone else have a problem like this?

ct67_72

this is a semi common problem with what I assume is the mercedes 722.6 transmission. is this a 3.7? if yes, than what happens, is on the valve body, connecting all of the solenoids is what we call 'conductor plate" it has electrical contacts and ribbons to connect the solenoids together. In this also is the trans temp sensor.
The ribbons tend to break, but they are tight so the cold contracts them and seporates the connection.
Also the trans temp sensors are notorious for going bad.
You need to check the codes and see what you have.
Also go under the vehicle and look on the pass side front of the trans pan area, there is an electical connector with a 1/4 turn type connector. These are also notoriously bad for leaking oil into the harness. Unplug it and see if its full of oil.
But definitely check the codes, and dont drive it taking off like that, you will burnm up the trans, then youll have to find someone like me to fix it

decarlod

Wow thanks for the reply!!

Yes its the 3.7. I am not much of a mechanic so where would I find these plates? Do you recommend I bring it in and ask them to replace the ribbons? Is is pricey?

I will take a look under like you said over the weekend and check out that plug.

Again, thanks.

Darren

ct67_72

Sorry, i should have explained little more. The plate is on the valve body. to replace the conductor plate, you need to remove the valve body and the solenoids and the plate just snaps onto the valve body. Its a very easy job, but not one you really want to tackle yourself if you are not mechanically inclined.
I would talk to a local reputable trans shop. they should be aware of the problems with these perticular units. Definitely check the codes and let me know if there are any.
Dont let any shop tell you it needs a trans or anything ridiculous. These are a great sales ploy to replace transmissions.
Also, just pull the trans dipstick and smell the fluid, see if its nice and red or a dark color, and see if it smells burnt.

decarlod

OK its been a few months. I got in touch with a mechanic that works for my brothers construction business. (He is a full time mechanic that works on his fleet of trucks) Anyway, I went on vacation last week and had him try this out since I didnt need it for a full week. He did exactly what you said could probably be the issue but he couldnt test it. Why? Because we had warm weather last week. So I got back over the weekend and started it up this morning and it was about 39 degrees. Well, this didnt fix the issue. I still have to let it warm up for a while before I can drive it. Any other ideas?

Thanks for the input.

Darren