broncojunkie

I've been having issues with my 92 5.0 E4OD not downshifting, when I stomp on the gas or pulling a hill. Mainly highway driving. I looked up how to adjust it in the Haynes manual, but it has me a little confused (instructions are very vague). I have a throttle cable and what I guess is the tv cable attached to the throttle body. I can remove the clip and slide it back and forth, which is how you adjust it, according to what I've read online. But the Haynes manual instructs to shift to nuetral, remove the clip and then have someone rotate the shift lever on the side of the tranny, hold it in place while you put the clip back in the throttle body end of the cable.

First off, I should state that I tried adjusting the cable the first way...just removing the clip and moving it a little. No matter what position I chose, I didn't notice any real difference in shift and there was still no downshift at highway speed.

Now, I'm wondering if adjusting it per the Haynes instructions would do anything differently? Also, my tv cable appears to go to an actuator thing mounted under the hood, near the brake booster...driver's corner near firewall. There are a couple vacuum hoses coming out of it. Could this be a vacuum issue? I did repair a couple small leaks the other day (other side of engine bay...mainly, the blend door actuator.) By reading everything, I would presume my tv cable would lead to the tranny. I realize it's electronic, so I'm guessing that's why it leads elsewhere. I'm just confused about how the kickdown works. If I knew, I might have a better understanding of how to fix it. It's getting annoying, as I've been using my truck for work here lately and driving a couple hrs a day.

Chris_1

iTrader: (1)

That actuator thing you're describing is the cruise control (I think, if I'm reading this right). Cable attaches to the throttle control beside the accelerator cable ?
I thought the kickdown was electronically controlled.

broncojunkie

I believe you're right about that being the cc. I forgot it even had it. Anyway, everything I've read online says the kickdown is electronically controlled, but my Haynes manual specifically instructs to adjust this cable. That's what has me confused. Although, like I said...the manual is pretty vague. It just specifies "earlier model" or "later model".

If the cable doesn't control the kickdown, what does? The tps? I did put a new one on last year.

Chris_1

iTrader: (1)

The TPS seems to really play havoc with E4OD's if it's not perfect from all I've read. I don't ever see the same thing about the 4R70W, no idea why.
But from what I understand, every shift including kickdown is controlled by the EEC.
It uses signals from the TPS, the MLPS and the PSOM - which gets it's info from the VSS, the transmission sensor, and the RABS system - a lot of possible weak links.
There's also the possibility of an actuator inside the trans failing ...
Start by checking for a code (you knew that) and I think the first thing I would test is the TPS - it just keeps coming up with shift problems.

broncojunkie

Thanks. Will check codes tonight. No cel on, od light flashing, etc...but we'll see what comes up.

broncojunkie

Well, it's a good thing I checked codes. No koer codes but koeo gave me 628 (torque convertor slipping) and 634 (manual lever position sensor bad). A little research on the mlps and I find out that they can wreak havoc on all sorts of things. I went ahead and ordered a new one. Haven't even been under the truck to look for the sensor yet. Might just be an issue with the plug, but it sounds like it's hard to reach. I read that the easiest way to reach it is by pulling the seat and carpet and then removing the access panel on the tranny hump.

Any of you ever fool with this one?

Chris_1

iTrader: (1)

The hard to reach sensor is the trans speed sensor left side near the back up toward the top.
The mlps is at the bottom on the left, right where your shifter cable attaches basically.
You'll figure it out pretty quick when you see the new one.

broncojunkie

Nice. Well, that's good news. I worked 15 hrs today, with an hr drive each way. Been way too busy to even take a minute to crawl under it. Part should be here by Friday, but not sure when I'll have time to put it in.

Thanks for the help!

broncojunkie

Put the new sensor in yesterday. Code hasn't come back, but it's still not downshifting. I noticed the truck does kickdown while driving under 55mph...just not above that speed.