1995 Z28 A4
Recently when i start my car and put it in gear, i will only have 2nd and 3rd gear. If i put the shifter into 2nd, it will start out in 2nd and stay in 2nd. If i have it in 3rd, the car will start in 3rd gear and stay in 3rd gear. If i start out in second gear, i can shift it into 3rd by moving it into D, and it shifts instantly, no matter how fast or how much gas im giving it. The car also slams into gear when i put it in reverse or any drive gear. Also the torque converter does not lock up when this happens

Heres the odd part, It only does it randomally. For example, i could be driving and it could be fine, i park it it and come back out and it does what i described above. If i start the car and all the gears are fine, it will be fine until i park it, meaning it wont lose the gears while I am driving, only if i turn the car off. Most of the time it is fine, but lately it has been more occuring that i dont have 1st and 4th gear.

So i hooked a snap-on solus scanner up to it and it had a code 81 in it which is 2-3 shift solenoid problem. I dont know how long the code has been there though. So i went into the data mode on the scanner and drove it around for a while. The 2-3 solenoid changed from off to on when i shifted it from 2nd to 3rd so that seems to work fine. But i noticed the 1-2 solenoid was always off. The scanner recognized what gear i had the shifter in, but it also said what gear was activated, and only 2 and 3 ever showed up, no matter what gear i had selected.

According to a chart i have, when the 1-2 solenoid is "off" only 2nd and 3rd gear would activate. When it is "on" 1st and 4th would activate, depending on the 2-3 solenoid being on or off.

If i had a bad 1-2 solenoid could it cause all these problems i am having?
Why would it only do it on a fresh start, why not while driving the car?

One more thing i should throw out there, i have tried putting a different PCM in the car and it does the same thing so i know its not that.

I know this post is long, but i had to give up all the info that i had, if you made it this far, thanks for your intrest and if you have any ideas please post! 3rd gear with 3.73 gears is killing me on the highway...thanks -Jeff

 

I would say it is a solenoid problem. Either not getting power or wiring/solenoid gone bad. I hear they are not too expensive or hard to change. It wouldn't hurt to check the electrical plug on the transmission...

 

I have checked the plug, and all other connections i could find, they all seem fine. I have another tranny (stock one) in the back on my shop that started to slip, so i will try taking a solonoid from that an putting it in my current one and see if thats the problem. thanks- Jeff

 

I had a very similar problem with my 4L60E not too long ago. It had shifted flawlessly for a long time, then one day, I started the engine and put the selector in drive and the engine bogged terribly seeming to have great difficulty moving the vehicle. After watching my tach, I realized that the trans was not shifting at all. It would start in 3rd and stay in 3rd. Also, if I put the selector in 2, the trans would stay in second gear until I selected D, at which time it would instantly go into 3rd.
I also suspected a solenoid failure. However, not having the time or proper tools to find out, I took the vehicle to a transmission shop and they told me that the internal wiring had shorted out against the case and needed replacement. So, the internal wiring harness was replaced and now I've got trouble free shifting 10K miles and counting.

 

Well i fixed the problem, I replaced the 1-2 and 2-3 solenoids and its great now. Possibly one of them worked only when it wanted to i guess.

goosechevy21, sounds exactly like the problem i was having, maybe your wiring grounded out causing the same solenoid to mess up. I dont know, im not a tranny expert, but i know mine shifts great now so im not complaining. Thanks for all the help though!