: Tranny Prob, Please help!!

11-01-06, 10:36 AM
I've got a 97 Canadian Born STS with approx 160K miles (mostly highway). In all honesty, the car was rode hard and put away wet for the last couple years. I passed it down to my daughter (what better car for a 16 YO during the Colorado winters). Recently, while she was driving it, she stopped at a stoplight and the car wouldn't move in any gear. After shifting in and out of gear, she got it to move just enough to get out of the road into a parking lot. Now it won't engage in ANY gear.

I checked the codes, it spit out a P1810. When i checked the fluid level, it was down about 3-4 quarts. I topped it off, and there does no appear to be a major leak. My delimma is this. The car has 160K miles. I REFUSE to spend 3500 on a new tranny. Is there a likely cause that could be fixed/replaced? The tranny shited fine before this in all gears, so if it's a valve body, I'd rather spend $400 and fix it myself. I'm only expecting 20-40K more miles out of the car.

I have no problems taking it apart. I've built my share of engines and manual trannys, so while this will be the first time I've cracked open an auto tranny, I'm willing to take the chance. Anyway, what's the downside? I screw it up and have to get a rebuild anyway? ANY insight would be GREATLY appreciated!!

11-01-06, 11:00 AM
P1810 TFP Valve Position Switch Circuit

Don't have any OBDII manuals myself, but it doesn't sound too bad.

11-01-06, 01:51 PM
It would seem that way, but I reset the code once and it came back, reset it again, and it hasn't come back, but the car still will not engage in any gear. reading the procedure for the code leads me to believe that the car should still engage with the code. I'm starting to think the code sets when something bigger happens also (ie, the alt light when your engine stalls)

11-01-06, 02:21 PM
It appears to me that you have an electrical problem. Either a wiring or device issue. I would start by getting a Helms manual and studying the trouble shooting procedure for that code. It might be as simple as twisting a couple of wires back together or a $20 part buried $2000 deep in the transmission but you won't know until you do your research and testing. Good Luck!

11-01-06, 03:39 PM
Read post # 4


11-01-06, 09:30 PM
"The PCM substitutes the value of the previous TFP Val. Position Sw. if it is consistent with the Park/Neutral status.
The PCM commands default line pressure.
The PCM inhibits Torque Converter Clutch.
The PCM disables steady state adapts.
The PCM disables garage shift adapts.
DTC P1810 is stored in the PCM history."

So I guess my question becomes, can these actions by the PCM result in the transmission NOT engaging in ANY gear? 1810 is the only code that set. I realize that it is possible to have it result in non-engagement in some cases but not in others, so I'd like to clarify if it's possible EVER with an 1810


"By grounding one or more of these switches with fluid pressure from the manual valve, the PCM can detect which gear range is selected."

It looks to me like the root cause could be ZERO line pressure. If so, what could cause that to fail catastrophically? No warning, no noise, it just quit (or so my daughter says....).

11-02-06, 12:11 AM
Broken pump shaft?

Not too sure about the internal design of this transmission, so I don't know if it's likely or even possible. Other pump related issues though can happen.

11-03-06, 07:16 PM

11-03-06, 07:54 PM
Your oil main pump has quit working. The amount you were low is just about equal to the amount that would drain from the reservoir down into the pan at shutdown. The stick doesn't show what's in the pan but the amount in the sump. What was in the sump is now in the pan and isn't being pumped back. It looks like you're SOL until you fix the pump. I don't know anything about doing that. Good Luck!

11-03-06, 09:42 PM
Thanks D.

I think you're right. There are several possibilities, all related to the pump (turning it, supplying it, or it simply not working...) and none of them sound like fun...

Caddyinfo's forums has a nice little procedure complete with pics on replacing the crank speed sensor without completely removing the powertrain, so I think I'll give that a go to get to the pump. I'll let you know if it works :)

11-04-06, 05:10 PM
You cannot "sneek in" and get to the pump----total removal is the only way. By then if you already have it removed, I would overhaul completely so you do not have to go in there again. There is another option though---find a used tranny from junkyard and do a swap. Hope I helped you a little........

11-04-06, 06:47 PM
This is the lionk to the procedure I'm refering to:


My read is that they basically drop the tranny without disconnecting the CV ect from the right side. It also looks like it doesnt require the amount of elevation for the car itself to remove the entire drivetrain from the car. From the picts, it appears it's a doable thing to replace the pump that way. I am worried though that if the pump gave up the ghost, it could have left it's share of metal shavings behind in the valve body. I figure I'll drop the bottom pan, look for the problem, then drop the drivetrain to see if it's an easy fix from the side. If it's not, I'm leaning toward picking up a complete used engine tranny combo and throw it in. The car has 160K miles, and maybe the powere steering pump on it won't whine like mine....;).

While I've got you Super Crew, one other quick question. My current plug/wire set also hit 100K miles and the car is running a little rough. Recently I also lost AC fan and replaced it witrh a new unit. It quit after about 2 months. Could bad wires have caused that? Shouldn't that $500 dollar unit be a little tougher it if did?