Strange trany failure

The trany on my 97 sable stopped shifting. Strange part is that the speedometer and odometer stopped working prior to the shift problem. I'm thinking that something electronic went bad. Any ideas?

I'd start by checking/replacing the Vehicle Speed Sensor. Oh, wait, on your 1997, I believe that function is performed by the ABS controller. Any chance your ABS light is on too?

-Rod

The ABS light is not on. However, I had the speed sensor replaced about a year ago. I'm going to get the check engine light read (or pick up a scanner and do it myself) to see if thats the issue. What function are you refering to that is performed by the ABS sensor?

I believe in the 1997 Taurus the ABS wheel speed sensors are used to provide vehicle speed data for the speedometer rather than using a Vehicle Speed Sensor as they did in previous years.

-Rod

I was mistaken. I just pulled up the speedometer wiring diagram from the Factory service manual, and in a 1997 Taurus, the speedometer gets its signal from the Vehicle Speed Sensor (VSS).

Likewise, the VSS is used by the transmission for determining shift schedules.

-Rod

Sounds like a VSS is the way to go. Its not an expensive part (about $20) so I'll just replace it as an attempt to diagnose the problem. I'll let you knwo how it goes. May be a little while till I can get to it though.

Sounds like a VSS is the way to go. Its not an expensive part (about $20) so I'll just replace it as an attempt to diagnose the problem. I'll let you knwo how it goes. May be a little while till I can get to it though.

I would fix it extremely soon if the odo is out also. that could cause legal issues when you are going to get rid of the car, if anyone knows about it.

ODO?

Not sure if its a legal issue anyways. I would have to junk it if I can't fix it. not many folks want a car that doesn't shift out of first.

Well then I'll retract my previous statement, especially if it's just gonna go to the bone yard, unless you get it fixed of course... I thought for some reason that you were still driving it (doh 1 for me :slap: )

what does ODO stand for?

ODO = odometer.

I managed to get a code reader on the car. I have 2 codes. The first is the speed sensor that we expected (thats the good news). The second is P-1744. Is the trany dead, or is this a secondary fault because of the speed sensor? Also, is this likely a faulty sensor, or is the torch converter gone and I should just donate the car so that I don't have to pay the insurance anymore?

I found this post:
http://www.automotiveforums.com/vbulletin/t415152.html
That relates to my issue. they don't mention anything about the VSS but do discuss my code. It seems to me from that post thread that the VSS is trying to tell the torque converter to lock but it isn't listening. Is it worth the effort of replacing the speed sensor, or is it time to toss the car?

Code P1744 indicates that excessive slip of the TCC was detected. It seems to me like the VSS could still be the culprit if the VSS is used in conjunction with the input shaft speed sensor to determine TCC slip. Certainly seems like the most cost-effective place to start anyway.

-Rod

Ill try the VSS and let you know how it goes.

Did the VSS fix the issue?

haven't replaced it yet. I have a different car to drive in the meantime, so it unfortunately is not my highest priority. I will post when I try it.

Please do. I'm getting the same P1744 code. Some other thread said that it was related to his cooling system, and after he did a flush the code went away. I may try the flush - if I do I'll post the results here also.

I replaced the VSS and drove it around for about 10 minutes. Had no trouble shifting and the light stayed off. I don't think that was much of a test but will let you folks know if it comes back over the next couple of days.