Transmission stuck in 2nd Gear

[st8w8]

I bought a 94 STS About 2 months ago for $800 with some tranny issues, besides that the cares in great condition. The interior is in excellent condition and the only thing wrong with the exterior is the trunk(Needs a pull down motor) and the front bumper down by the fog lights(Found a used one for $285). So overall all I believe I got a good deal. Now the 2nd gear starts are the problem. Took it to a few Transmission shops and they're all telling me electrical issues. But before I go into spending any money, which I was told anywhere from $600 to $2800, I need to know a few things. Could this be an ignition switch issue? I was told by GM Tech that it's a common problem in the 94 STS. I also have these codes I pulled.

P056 (E056) ........................................ Transmission Input Speed Sensor

P059 (E059) ........................................ Transmission Input speed sensor

P076 (E076) ......................................... Transmission Pressur

P117 (E117) Open/Short Solenoids/Solenoid Wiring (Transmission)

P109 (E109) Keep Alive Memory (KAM) Reset/PCM has lost primary battery power

I would appreciate any help. This is my third cadillac and I absolutely love this one the most. I don't want to lose the car.

[BodybyFisher]

Check the main plug, clean it out, and reset it

The input speed sensor problem would not cause second gear starts

My guess it that the P076 and P117 codes need to be researched, maybe you have a bad pressure solenoid or wiring to it

[st8w8]

I'm new to fixing cars could you help me in locating the main switch. I have an idea but don't know exactly where to look.

[BodybyFisher]

I'm new to fixing cars could you help me in locating the main switch. I have an idea but don't know exactly where to look.

Its the main plug, and it is located on the driver side, down below the air filter box behind the ABS unit, it looks like this

[Cadillac Jim]

If your car is in the Valet mode it will start off in 2nd gear. The Valet mode button is in the glove box.

[st8w8]

The only buttons in my glove box are the fuel door and the trunk release button. Also I cleaned the main switch and reset it and I'm still having the same problem. Any suggestions on what to do next?

[Cadillac Jim]

In my 1997 ETC the valet switch is a push-on, push-off button in the glove box. My fuel door and trunk release buttons are on my central console (and are disabled in the valet mode). Look in your owner's manual for the valet mode. Since the purposes of the valet mode are to protect the car from prying fingers, the switch is where you can lock it away; since your fuel door and trunk release are in the glove box, that may *be* the valet mode, and you may not have a button that puts the transmission in the valet mode.

Another user switch that can cause the car to start in second gear is turning off the traction control Also, problems that set a traction control code will automatically turn it off and thus cause the transmission to start in second gear. My car has the traction control button in the glove compartment also; check your owner's manual.

In the meantime follow BodybyFisher's advice and make sure that all the electrical connections on the transmission are clean and tight. That could solve all your problems without further ado, and you are going to have to do it in any case.

[BodybyFisher]

Good Idea about the TC button Jim, I had forgotten about that.

However, I looked in a 93 owners manual and dont see the ability to turn the TC off, its possible that that feature was not introduced until later

[Cadillac Jim]

So, no valet mode, no traction control disable, and we are left with just the transmission, probably operating in a default mode because of the codes. Fix the electrical codes and it will likely shift normally.

[st8w8]

I cleaned the main switch and still no luck. I also cleared my codes and ran them again. All the codes I posted above are gone except for these two,

P076 (E076) ......................................... Transmission Pressure Solenoid

P117 (E117) .................... Open/Short Solenoids/Solenoid Wiring (Transmission)

[Cadillac Jim]

At this point you need to start troubleshooting the P117, the wiring problem. The other code will probably go away when the wiring is fixed. Someone with a 1994 FSM? We need the pages on P117.

[st8w8]

Sorry to keep bugging you guys. I have a Haynes GM Manual and it covers Deville ( 1994 thru 2005) and Seville (1992 thru 2004) but theres nothing in there referring to it.

[BodybyFisher]

The Haynes manual is useless, if you are going to keep the car find a factory service manual.

Here is a diagram of the transmission plug.

Measure the resistance between terminals C and D (Pressure Control Solenoid Valve). The resistance should be between 3 and 8 ohms.

[st8w8]

Good news!!! I went down and checked the connector again and when I pulled it, it came loose the same way it did when I first checked it. I made sure it was securely fastened and when I start my car and drove off it jerked real hard as if trying to shift. I drove it a little more and its shifting. The only problem is it's still shifting a little rough from 1st to 2nd. After 2nd gear it's smooth sailing. Should I change the fluid or leave it alone?

[BodybyFisher]

The ISS speed sensor will cause it to shift rough, it needs replacing

[Cadillac Jim]

Yeah, clear the codes, drive it again, and recheck the codes. Check the codes before you turn off the key because once you do that everything goes to HISTORY and you can't tell what is CURRENT. But, it sounds like you may have cleared the main problem.