Have a really odd problem with my wife's Edge, while driving sometimes the wrench light will come on and it will not up or downshift. If you come to a stop, you can almost not get it moving again. I determined that it is getting stuck in 4th gear. You can put it in reverse and it will not move at all. the only fix is to shut it off, wait a few seconds then restart. It makes a nice loud bang, the wrench light is off and it operates normally. The dealer told me without the light on, they can not pull any codes, it would have to be brought in once it happens. Well good luck with that, it would do much damage to continue driving it that way. It had happened about 3 or 4 times in the time we owned it until last week, it happened once on tuesday and twice yesterday. I see a TSB that reads "DTC P0771, P0774 and/or starts in 4th gear from a stop, harsh 4-1 downshift on drive away at 3mph. 6F50 transaxle built prior to 01-10-007. KB*" This is very similar but mine will not shift until restarted. I am going to talk to the service dept today to see if there was ever a fix for this and see what we can do. Has anybody else seen/heard of this?

 

The real issue here is that the computer has seen a problem related to the transmission, when this happens the computer turns the light on and cuts the power to the transmission. This transmission without power will start off and stay in 4th gear until the key is cycled and the computer resets, then when the computer sees the problem again it starts all over.

The key will be to figure out what the computer sees as a problem, to do this you will need to get the code that the computer has set. This code should be able to be retrieved without the light being on, I am surprised that the dealer told you that they can not do anything without the light being on.

The problem could be a simple fix like a sensor or a switch.

Maybe take it to a transmission shop that you trust.

 

The dealer is being stupid. When the wrench light is on a code is stored in memory. It will remain there for about a month after the last time the light was on.

I agree with taking it to an independent shop.

 

Thats what I thought also. I have been doing a lot of research and it seems a lot of people with similar problems are having the TSS and OSS replaced to fix it. I would still like to get the code read to be sure. Doesn't look like too bad of a job to replace them, the worst of it will probably dealing with tranny fluid, I hate the smell of that stuff and it is messy.

 

Well, no codes stored. I dont know if that is the difference between the engine light coming on and the wrench light coming on, but thats what I got. The wrench light comes on when it happens, goes back off after restart. So now I dont know what to do. I dont feel like throwing parts at it to try to fix it. Really frustrated. I can't force the issue to duplicate, which is what the dealer wanted to do. They wanted to keep it, dont really have the time or pocketbook for that.

 

Update: Finally it set the engine light on and stored a code, looks like I have to replace the TSS (Turbine shaft sensor). Cant wait, should be great fun from what I have read.

 

Final update: Changed both the TSS and OSS over the weekend. Found where someone scanned in the directions on how to change the oss from a Ford repair manual, and that made the difference. Was originally only going to change the TSS since that what was throwing the code, but since I had to completely remove the valve body to feed the wire through, I decided I would go ahead and change the OSS as well. $75 for two sensors, $35 for mercon V, and about 4 hours to do the job. The dealer wanted $1000, I think I came out ahead. Fairly simple if you are patient and follow the procedure carefully, lets just hope this takes care of it for good.

 

I hope that fixes it for you. Good on the diy part and saving all the dough.
My 07 has been flawless on the tranny, but had to change a front hub bearing. I've got 85k(wife actually)and she loves it,but I'd just as soon drive my old 99 exploder and I think it's for the better visibility.