Tranny problems - Again!

[Clement]

94 Merc Sable, 3.0L, 120K miles. Transmission is not shifting out of 2nd.

This problem showed up previously, and was cured for about 2 months by disconnecting the battery and thereby resetting the computer.

Problem surfaced again a couple of days ago, and now the 'cure' only holds for a few hours before the problem shows up again.

Disconnecting the battery/depressing the brake pedal for a while/ trying the ignition cures the transmission shifting problem for a short time, so I'm positive it's not a mechanical problem.

Would replacing the computer fix this?

Any other 'easy' fixes available?

This car does not have odbcII, I believe it is odbcI. Advance auto does not have a code reader for it.

 

[Clement]

From www.autozone.com

Only $110 for a remanufactured computer. Would this be what I need or is there more to it?

Search Results: ELECTRONIC ENGINE COMPUTER


Click "Buy Online" beside the item you'd like to purchase from AutoZone.com.

Click "Add to Store List" beside the item you'd like to add to a shopping list that can be sent to and paid for at your preferred AutoZone store.


ELECTRONIC ENGINE COMPUTER for a
1994 MERCURY SABLE
Normal Stock
Special Order
Not Available



Item Part
No.
Warranty Core
Value Unit
Price Availability
Store Web
CARDONE 78-5771 3 MO $90.00 $106.99
O.E.M. #F44F-AA

CARDONE
R & R ITEM ONLY 78-5772 3 MO $85.00 $180.99
O.E.M. #F44F-BA

CARDONE
R & R ITEM ONLY 78-5777 3 MO $244.99
O.E.M. #F44F-HA

 

[terminaldegree]

I dunno, $110 is a lot of money to throw at a hunch, especially considering that your transmission doesn't have a reputation for longevity. I would start asking around for a reputable shop in your area, or maybe consider selling/trading the car if a rebuild is in your future, as the cost of the rebuild may exceed the value of the car.

If the parts store has a lenient return policy, you could try swapping the computer for a day and bring it back if it doesn't work.

 

[Clement]

It is a lot of money, but it is a **** of a lot less than a new-er car.
The transmission was replaced at about 60K miles. When the battery disconnect/ecu reset takes place, the transmission shifts fine from 1st through OD and back. But it doesn't stay that way, until you reset the ecu again. I don't see how a rebuild would effect this, as the transmission works, but whatever controlls it is not telling it to shift. A faulty sensor/solenoid shouldn't be effected by cutting the battery power either, should it?

On this car, same as the '94 Ford Taurus, 3.0L, what actually controlls the transmission? Tells it to shift or not to shift?

 

[benjamming]

Don't just throw parts at it. Take it to a good transmission shop & have them scan for codes first. The shops around here will do that for free even if it is OBDI as my car is.

 

[Clement]

Throw parts? I might end up throwing bricks!

It may also be the transmission control solenoid - a fluid pressure switch that controlls the shift into higher gears. This may be most likely and is about $25.

This car/transmission model has a long and well documented history of problems. I was hoping somebody had seen this issue before and knew the solution. I found the above info from another site where someone with a '94 Taurus's tranny that wouldn't shift out of low gear. That's exactly what mine is doing.

The hard part of taking it somewhere to get it looked at is that the car can only be driven in 2nd gear - about 30-35 mph max. The good shops are far enough away that it would require having the car towed.

I'll have to look around for someone with a code reader close by. Otherwise, I'll start throwing things!

 

[Alan]

Go to alldata.com and look to see if there is a TSB for the tranny.Maybe it just needs to be reprogrammed.

 

[1sttruck]

Auto trannys compete with fuel injected engines for complexity, the number of parts, sensors, actuators, controllers, and the potential for problems. As others have mentioned do the troubleshooting so that you're replacing the right parts, start by checking for codes, but on an older car don't get your hopes up. I have a 93 Taurus that after fixing several problems still sputters a bit at start up when cold, something that I'll need a fuel pressure gage to check as I checked a number of other electrical and vacuum systems. It comes up clean on codes, even the sequential test which looks for a weak cylinder, so based on my experience having the shop look at it would be a waste of time. Awhile back I had three different shops look at a intermittent check engine light over the course of almost a year, no one found anything, and I fixed it by replacng the O2 sensor.

I very much prefer the manual tranny in the truck.

 

[terminaldegree]

I didn't know that the tranny was rebuilt already. You may want to try posting this question at www.flatratetech.com in the ford support forums. They have about 10 Ford techs who moderate that forum, and can provide some insight as to likely suspect parts, or which ones to throw at the car if you have to go that route...

I assume you've done the intermediate 30k services on this unit. Make sure they know the repair and service history in addition to the problem.

 

[Clement]

Thanks - posted over at flatratetech.com

Don't know what you mean by intermediate services but I've dropped the pan and changed the filter 2x on it myself, and it was serviced once by Ford before that.

 

[Clement]

Went to take it to a garage last night to try to get any codes read. The tranny started shifting normally as I drove there! Darn cars!

Wouldn't of work anyway, the garage couldn't read odbcI

 

[punisher]

It's not rocket science:

http://www.troublecodes.net/Ford/

Ignition off, jumper the test connector to pin 2 (connectors on firewall ,near AC accumulator), ignition switch to the on or run position (don't actually start it), and watch the MIL light blink and get your codes.

If it is an electronic problem, you should have some stored codes to go by.

I cannot believe no one can pull OBD1 codes, that is a sad commentary on shops.

 

[1sttruck]

Reading codes by watching the blinky light works well, especially considering that the local Ford dealer charges $130 just to do the test. It might take a prectice run or two. In addition there are some interactive tests that you can do with the KOER (key on engine running) test, such as hitting the brake, turning the steering wheel, goosing the engine, and when done lightly tapping the throttle and it'll check each cylinder for low output. Another sequence involevs driving in a specific manner and then checking codes again. You're supposed to do all of this before hooking up the tranny tester.

 

[TxGreaseMonkey]

Actron sells a scanner for around $80 that easily retrieves DTCs. Sears, Advance Auto Parts, and Autozone carry them.