• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

TCC fails to disengage

A

aa0ut

New CEG'er
Joined
Aug 14, 2008
Messages
23
What it is: 1997 Mystique Zetec/ATX

What it does:

The TCC fails to disengage, killing the engine when coming to a stop while in "drive". It happens always when the tranny is stone cold, sometimes during early warmup, and never after about 10 minutes of driving. Throwing the tranny into neutral does not help; the engine kills when putting it back into "drive". However, if I turn the engine off mometarily as I'm approaching a stop, it seems to clear.

The CEL does not illuminate, nor are there any DTCs detected when performing a scan.

What I did:

I purchased this tranny from a salvage yard and hired a local shop to install it, as the old one was shot when I bought this car.

I changed the new fluid after only a few miles, as there was evidence of water mixed with the fluid (the salvage yard pressure washes them before they sell them, and I think some water got inside). No improvement was noted.

What would you suggest I try before taking it to a pro? I possess average shade tree mechanic skills and have access to very basic test equipment.

Regards... Mike
 
I know this is obvious, but......

I know this is obvious, but......

Did you try to push the overdrive lock out button on the left side of the shift lever? If it is working you should get an OD OFF light in the dash. Then check to see if the problem continues.

Let us know
 
Hi Andres,

Yes, I've tried that. If I keep it out of OD initially, the problem doesn't occur, as the TCC is prevented from locking up to begin with.

If I put it in OD with a cold tranny, then the TCC fails to unlock when it should. Taking it out of OD does not release the TCC. I've tried toggling in and out of OD, and the relatively harsh upshifts/downshifts tell me the TCC is indeed still in lockup. This harshness disappears upon warmup (when it then works as intended).

One strategy I have not tried is to achieve lockup, then shift out of OD and drive at a steady speed to see if and when I can feel it unlock on it's own, when operating temp permits it to do so.

I may try some SeaFoam TransTune, recommended by a friend. Perhaps the TCC solenoid is suffering from varnish-induced stickiness or maybe there is still some moisture in there that the SeaFoam is said to address.

I might add that initial engagement seems to be normal, locking up after about a minute of driving in mild ambient temps.

Regards... Mike
 
Simple repair??

Simple repair??

You might check the wiring on the connectors on the trans to see if anything is shorting out first. The MLPS, the TSS, VSS all have wires going to and fro make certain that the wires are not cracked or shorted.

If it is a valve body and the symptoms seem to point to that, I don't remember but you might just get away with replacing the appropriate solenoid. or go to the junkyard and get another valve body.

You can replace the valve body in the car, but you gotta pay particular attention to the linkage to the shift rod. Get the aftermarket auto trans book.

You will need alignment pins to reinstall the replacement valve body, but they can be made from some longer bolts than stock, cut off the heads and slot for a screw driver. Just as good as the factory ones and one heck of alot cheaper.
 
Ha! Now I wish I would have kept the old tranny. The valve body was known to be good in that one... probably would have been worth it to forfeit the core refund.

I'll try the Seafoam treatment first, expecting no miracles but being pleasantly surprised if one does occur; then I'll focus on the connectors and the valve body.

Thanks for the advice!

Mike
 
andreslobo said:
You might check the wiring on the connectors on the trans to see if anything is shorting out first. The MLPS, the TSS, VSS all have wires going to and fro make certain that the wires are not cracked or shorted.

If it is a valve body and the symptoms seem to point to that, I don't remember but you might just get away with replacing the appropriate solenoid. or go to the junkyard and get another valve body.

You can replace the valve body in the car, but you gotta pay particular attention to the linkage to the shift rod. Get the aftermarket auto trans book.

You will need alignment pins to reinstall the replacement valve body, but they can be made from some longer bolts than stock, cut off the heads and slot for a screw driver. Just as good as the factory ones and one heck of alot cheaper.
Click to expand...

If it were an electrical circuit fault, I would expect a corresponding DTC to be posted. Of course, this does require a scanner capable of supporting "manufacturer-specific" codes, not the el-cheapos that most parts stores provide for customer use. The el-cheapos will miss most of the transmission-related fault codes. If that is what was used, then I'd consider the scan to be incomplete. I suspect this is in play....

The valve body sells for around $250 for a rebuilt unit. You cannot replace a single solenoid by itself, you have to replace the whole assembly of five solenoids at an additional cost to the VB. Any VB you get from a JY is likely to have problems (either now or later) since they were under-designed from the get-go and most fail eventually.

The workshop manual has a whole list of things to check to pinpoint the fault. It would be your best reference to step through to pinpoint the fault.
 
I think I fixed it!

I think I fixed it!

Hi,

The Seafoam may have worked. After a couple of short drives it seems to have come out of it.

I'll drive it more just to rule out the possibility of an aberration, but it worked flawlessly today.

I'm wondering if there was some moisture remaining that the Seafoam has "dried", kind of like what Heet does in a fuel system.

Could water in the innards cause the symptoms that I described?

By the way, my friend who sold me the Seafoam (he owns a parts store) used it in his own tranny which was experiencing evident valve problems and it cured his symptoms. That was 3 years ago and it's still working. Perhaps this is one of those products which actually lives up to it's claims. We'll see.

Regards... Mike
 
Update on sluggish TCC

Update on sluggish TCC

The Seafoam did not help after all.

So, I drove it for a few weeks, then changed the fluid again, this time to Amsoil Universal Synthetic fluid.

It gradually improved and now functions perfectly (knock on wood). I don't know if it was the synthetic fluid or time that fixed it.

I described this experience to my independent mechanic friend: his theory is that the water I found in the tranny did not enter when the salvage yard cleaned the exterior of the unit, but rather, the donor car may have been in a flood, causing corrosion/roughness in some of the moving parts of the valve body. He thinks that by "working" the tranny over a period of time, the moisture-damaged parts became "polished" enough to work smoothly again.

Regards... Mike
 
You must log in or register to reply here.
Back
Top