automatic won't shift from first?

[mezer]

Hi, so I've wanted to buy a 92-94 talon for a long time, and finally received the opportunity from a friend. He offered me a good deal, and I became the owner of a 92' Eagle Talon TSi AWD, unfortunately it's an Automatic, and unfortunately that's my current problem

The basic problem:

The car goes into neutral, drive, reverse, etc fine, but does not shift up from 1st, it doesn't even attempt to. Note-- It is not in 3rd gear, it IS 1st gear. The transmission light is on on the dash, but I haven't had the time to check the codes, and figured I'd ask here real quick if anyone knew whether this was a bad transmission or something electrical internally since I have a spare transmission I can steal stuff from.

Some background:

Bought the car from a friend, who purchased it from another guy, he said it had a bad timing belt tensioner and that the guy he got it from said the transmission was also bad. I replaced the timing first, and noticed while doing this that the flexplate was only held on by 1 bolt and was pretty much destroyed. When I purchased the car he also gave me a 92 awd tsi transmission from a junkyard, so I was torn as to whether the transmission was actually bad or if it was just the flexplate.

I was pulling the transmission out to replace the flexplate and realized the bellhousing was cracked, so I figured screw it and decided to throw the junkyard transmission in. That leaves me with my current problem. Also please note that when the original transmission was in, that the transmission light did not come on on the dash. I started it to see if the timing was right and to assure valves weren't bent, so I know this for sure.

So uh, anyone have any clue?

 

[BoostedTalonTS]

Double check that you have the correct plugs plugged in... I know this sounds like a stupid thing to check, but the ATs have two of the same physical plugs that will plug into the wrong plug on the car side:

One has only 3 wires in a 4 pin plug (the solenoid plug)

The other has all 4 wires in the 4 pin plug (speed sensors plug).

If you have the two mixed up then the solenoids will never get the signal to shift.

If that doen't work then try swapping the valve body and/or just the solenoids from the spare tranny.

A similar thread (w/ pics) is here:

http://www.dsmtuners.com/forums/aut...-awd-t-tranny-wiring-harness-differences.html

 

[mezer]

Thanks for the reply! Yeah, everything is plugged in correct, I just tried the speed sensor solenoids with no luck

So I'm going to try the valve body tomorrow, hopefully that fixes it. I actually had my friend pull the pan off the original transmission while I did the solenoid switch, and man I hope I don't have to think about putting it back in, I've never seen so many metal shavings in my life, this poor car has been through hell and back it seems.

 

[mikuda]

Sounds like you have a fried TCU. The transmission computer is behind the dash behind the ECU, it lies flat. Typically when the TCU fails, the car stays in one gear, usually second, but it can be any gear. You also get the transmission light on AWD automatics. I had this happen to my car and a friends all in the same month.

 

[mezer]

Yeah, I was wondering about that possibility too, but from what I've read on the forums, everyone has said the car will go into limp mode and stay in 3rd gear if that happens? That's what has puzzled me on that issue. Maybe since the transmission never has run in the car though I could see it being stuck in 1st instead? Oh well, I'm going to try the valve body first since it's free, I don't want to think about how much a new TCU would cost.

 

[casperfast]

well, does the speedometer work? if itdoes you know ## cables are correct. fluid level? next tps any good? the tps controls shift rpm

 

[BoostedTalonTS]

well, does the speedometer work? if itdoes you know ## cables are correct. fluid level? next tps any good? the tps controls shift rpm

^^^ NOT TRUE ^^^

1Gs are mechanically (speedo) driven... The speed sensors are for the AT trans operation only, FYI.

TPS is only referenced by the TCU... I don't think that a TPS failure will hold it in one gear all of the time. -It will cause erratic opperation though, depending of the nature of the TPS failure.

 

[BoostedTalonTS]

Thanks for the reply! Yeah, everything is plugged in correct, I just tried the speed sensor solenoids with no luck

So I'm going to try the valve body tomorrow, hopefully that fixes it. I actually had my friend pull the pan off the original transmission while I did the solenoid switch, and man I hope I don't have to think about putting it back in, I've never seen so many metal shavings in my life, this poor car has been through hell and back it seems.

Just don't forget to get A LOT of brake cleaner & disposable rags... You WILL need them

In case with my AT, I found that the solenoids are in fact different from my OEM AT... Everything worked after I swapped in the OEM solenoids and the plate that they were mounted to (separated from the valve body) as it was different from the 91 AWD AT trans that I got from IPT. -It had different ohm rated solenoids.

Before I'd go pulling apart the valve body though, I'd double check the ohms of each solenoid on the tranny side first. -Compare the two different valve body's solenoids ohm ratings... That way you can at least eliminate that as a possible failure point & clean them up at the same time if it is..

Good Luck

 

[mezer]

Well I pulled the TCU out real quick to check it and make sure it was okay before dropping my pan, and it's got black gooey marks on the board in a couple spots next to the big capacitor, and smells like rotten fish Looks like the stupid capacitor leaked a bit, and since I can't find any on ebay I guess I'll be calling junkyards, how much do these typically go for?

 

[BoostedTalonTS]

I have a spare TCU... As long as your's has a 2 plug configuration then it will work. -PM me for details

 

[mezer]

It's a 3 plug configuration, MD750092, it's the only one I couldn't find on ebay, . I found someone parting out a 92 though, so hopefully he'll sell me his and it'll be good. Thanks for the offer though.