: Code P094 Shift A Solenoid Speed Sensor Where and what is it 94 Concours?

08-05-04, 04:46 PM
I have a 94' Concours and my check engine light came on. I checked through the codes and found P094 (E094) ........... Transaxle Shift "A" Solenoid Problem (Vehicle Speed Sensor). I read up on it and noticed that the pan and valve body need to be removed. Does anyone have any pics of this or parts diagram. I looked at the one pic in one post but it was hard for me to see much in it. Any info would be appreciated. Thanks.

08-06-04, 09:35 AM
a) the job is a mess, be prepared.
b) drop the transmission pan, and careful removing the tranny gasket, it is re-usable. Once you clean the pan, you can reset it with gasket sealer.
c) Okay, before you drop the valve body, you must disconnect the solenoid harnesses and there is a steel rod that actuates a valve spool that must be disconnected. It has a spring steel retainer clip that must be lifted and slid back for the rod to be disconnect. BE CAREFUL, spool can slide out, you do NOT want to damage this piece.
disconnect the solenoid electrical connectors and the mechanical linkage. The linkage has a metal clip you lift and slide.
d) remove the valve body screws, and drop the valve body.
e) place the valve body where you can afford a mess, it will contually leak. Best thing is to set it on cardboard on a bench.
f) remove the two clips holding the solenoids, careful they are spring-loaded and will fly
g) remove the screws holding the "large" portion of the valave body split, this is where the solenoids are located. remember the screw locations, there are about four different screw lengths
h) CAREFULLY remove split, there are 4 steel check balls loose inside the split (about 1/4" diameter, they will fly, as well)
i) inspect spacer plate, if the black coating is not chipping off you can re-use it, otherwise plan on spending another $ 70 at the dealership parts house. If you replace it you will have to remove the "smaller" split, as well. It also has three check balls.
j) replace the solenoids
k) now comes the fun,....you will note three holes in the spacer plate where three of the check balls reside, seat them there (appr. 3/16" diameter with a smaller relief hole next to it, as I remember). The fourth check ball will need to be inserted in a spherically-cast cavity which is near one the solenoids. You can set it with grease, I re-assembled successfully without using grease.
l) re-assemble valve body, carefully and equally torque.
m) you will note a square black plastic item near one of the solenoids, on the end. Replace this platsic filter with the new filter in the solenoid kit. The kit will also come with an L-shaped bracket that is to be used to "capture" this filter and keep it from backing out. The kit also comes with a slightly longer screw used to mount the bracket to the valve body (discrad the old screw).
m) re-assemble valve body to transmission, hook up linkage and electrical connectors
n) replace both tranny filters
o) replenish fluid
p) reset codes

I just replaced my solenoids and it is DIY repair if you are mechanically inclined and like working on cars.

08-06-04, 09:50 AM
I tried to attach 2 diagrams of the solenoid placement in the valve body, lets see if it will work this time, they are in PDF format so you will need Adobe reader to open them.


08-06-04, 11:58 AM
Thanks for all of the info John. I have Acrobat reader but still couldn't open them. Can you send them as a jeg or post them? I would appreciate it.

08-31-04, 08:22 AM
I just had the same problem and fixed it myself. These directions were great. The only problem was, I didn't put that L clamp on so I was back at it the next day. I did take some pics and there are some real good ones on here. If you go to forums, northstar performance and technical info and and searth this forum, type in pics. Look for solenoid/valve body/trans pan pics.

10-23-05, 08:08 PM
Great directions.
I have a "95 SLS and would like to know if these instructions will work for my transmission. My transmission slips when it shifts into overdrive (OD) started last week. I've been driving it in third gear til I can find out what to do to repair.
Thansk for a reply

10-23-05, 10:27 PM
Those instruction are for all 4T80E transmissions, which is the trans that is teamed up with the Northstar. So to answer your question in a word, yes.

09-20-09, 04:06 PM
Hello Everyone,
My 96 STS suddenly started slipping out of 4th and now 3rd during the last two days. It has 196,000 miles. I had a friend plug in his Snap-On computer. He cleared the Bank One Oxygen code, but that was the only code. There are not any stored transmission codes. The car has been running perfectly every day for the last couple years. Two weeks ago I started hearing a whine which I thought may be coming from the power steering pump. Now I think the whine may be transmission related because when it is whining 3rd and 4th gears don't work. I pulled the pan and everything looked normal.

My questions are;
Since there are not any codes, does that mean the solenoids are working properly? Or, Could the solenoids be malfunctioning without sending a code?

Also, I have read on a different thread that there is a 4th Servo with a piston seal and a cover seal which are replaceable without removing the transmission. If the 4th Servo is stuck, or ripped, or leaking, would that throw a code, or just malfunction and possibly not throw a code?

Also, can the side cover be removed from the transmission without removing the transmission?

Thank you everyone for any input!

09-20-09, 05:20 PM
A shift solenoid should set a DTC. Your car has on board diagnostics. There is no need for a scan tool. See the sticky at the page and pull your own codes. Note sure if the servo would set a DTC or not, but if it is electronically monitored it would.

No, officially the side cover cannot be removed without removing the drivetrain. There is a trick however that will allow it. It involves replacing all the cradle bolts with threaded rods and a nut and washer. Then back off on each nut to lower the cradle, lowering the left side more than the right until you have the clearance needed (12"-14" I seem to recall).

09-20-09, 06:27 PM
As Ranger posted: Pull your own DTC's with the car's built-in system. Aftermarket scanners have a habit of missing quite a few codes.

Go to the top of the main Northstar or Seville page and read the entire post "How to pull codes" before you start. Then return to the thread to decipher the OBD-II (OnBoard Diagnostic protocol -II) P,B,C, and U codes.

Remember that if you clear P codes within a week or so of an emissions test the car will fail - it will send the test set a "not ready" code.

09-21-09, 09:08 PM
My questions are;
Since there are not any codes, does that mean the solenoids are working properly? Or, Could the solenoids be malfunctioning without sending a code?

The solenoids can stick without setting a code. Not uncommon at the beginning of failure.

Not sure about your other question

09-22-09, 09:24 PM
Hello submariner409,

Interrestingly enough, I dropped the pan, changed the filters, and filled it back up with cleaner and fluid. After a day, the transmission started shifting through all four gears properly. It still whines most of the time, but even the whining is reduced. A couple 3rd and 4th shifts have malfunctioned, but yesterday and today I have driven it about a hundred miles in stop and go traffic without a malfunction. It is not shifting perfectly every time, but close to it. On a few occasions it has kind of shuddered into the next gear as if it took two or three quick tries to engage, but it did engage.

So, as a precaution, I have ordered the 4th servo gasket and ring, and intend to order a new A,B Soleniod kit. If the whining does not quit within a couple weeks, I may go ahead and change the servo seals and the A,B Solenoids anyways. You could be correct in the prediction that this transmission is at the beginning of a problem.

It is worth it to me to change all this on the chance that it will fix or prevent a big problem. If the shifting problem returns, then I will have to determine if I am willing to spend the big bucks having the transmission removed and repaired or replaced.

Two things I have learned so far; 1) change the transmission fluid at least every 50,000 miles. The 100,000 mile transmission fluid change interval is just as bad of a plan as the 100,000 mile coolant change interval.
2) Don't buy new filters for this transmission. The filters in the Northstar Transmission can be cleaned. Just clean them and save the $35. They have a wire mesh screen which is very easily cleaned. It is not the material that many transmission filters are made of which are single use. As a matter of fact, the filters in my transmission only had a tiny amount of debris stuck to them. They had not been touched in 90,000 miles.

Thanks for the good ideas!

09-22-09, 10:52 PM
Jon, The actual "filters" are deep in the trans and only get changed at tear down.

For what it's worth, I've never had a problem doing trans service at 100K.