Hey Adams' Apple,I have been following some of the post you have been replying to and you are the expert on 4T80E trans. My question if you have time to answer is this: I have a 1996 Seville SLS and my trans is not shifting to 3. It shifts from D! to D2 but D3 it spins like in neutral. If I manually place in D3 it moves but does not seem to D3 maybe D2. Could this be a solenoid? or clutches. I need some direction before I move forward. Additionally my ISS have been out for the last two years but has been driven with no apparent affect. This just recently started. Any thought?

Hello. I was wondering if you've had a chance to check out my post yet. Basically, my caddy only has 1st gear. I've replaced the shift solenoid and bracket kit, and a trans shop replaced two wires leading to the solenoid which I have tested to be good. PCM throws a few codes relating to 1-2 shift solenoid circuit, 2-3 shift solenoid circuit, and TCC PWM solenoid circuit. This car has had 3 different transmissions in it, all with the same problem. I was thinking maybe bad PCM? Or bad TCC solenoid? I'm not sure, I'm completely stumped on this one. Could you maybe help me out with this? I would greatly appreciate it bud. Thank you for your time.

Hey, I was told to talk to you from another user on here. He said you're a trans guy. I posted an article in the transmission thread called "any 4t80e guru's on here?" If you would take a minute to read it and shed some insight on my problem, would be greatly appreciated. Thanks for your time.

Good evening:

In an earlier post, you commented on the plastic clip on the linkage inside transmission at valve body. You mentioned brittle, easy to break, etc. Can you tell me the 'correct way' to get the thing off? I was in junk yard yesterday in 40 degree rain storm, and just gorilla'd one off just to get to the valve body, but there has to be a 'right way' to get it off. And if I break it, other than taking your (excellent) schematic/diagram to a dealer, do you have a part # for the clip? Thanks,

adam i have a 97 deville with a theft deterent problem may not start. will not crank or communcate data on dic. pndr123 flashes with key on. most electric functions don't work i.e. radio fuel gauge door locks truck release. paid 300 for a gm tech to find no solutions. help

To get the codes on your '93, with the key on(engine OFF), press and hold, at the same time, both the "OFF" and "WARMER"(or the red/hot temp button) buttons on the A/C control panel. Hold both buttons down until you see the display under the speedometer light up all of the segments. From there, it will display ALL of the codes that any of the systems have. Once it displays all of the codes, it will read "PCM?". From there, you can either turn the key off, or press the "Auto" button to get out of the diagnostic mode. Be sure to write down ANY codes that come up. If you miss some, press "Auto", and then start the diagnostic routine again by pressing and holding the OFF and WARMER buttons again.

It will take a little time on the wiring diagrams, but I can send them to you...might be tomorrow, or later. I am on dial-up here at home(yeah...I know), so it's really hard to send large files via e-mail.

hth

can you please send me diagnostic routine for checking the electronics in my transaxle, as well as the wiring diagram for the trans/vehicle. have a 93 seville 4.6 with 4t80 ...has second gear and reverse only. no codes have come up that have anything to do with solenoids yet. would like to check them using obd but do not know how.thank you soundtree@msn.com

Hey there Adam's Apple. I have read a few of your answers to other people and I hope you can help me. Go to a post in transmission forum called " 4t80E side gear problem????" It was posted by me. Any help you can give will be greatly appreciated. Thanks for your time. Roger (70torinocobra)

The pumpshaft runs all the way thru the valvebody/pump assy. It would require trans removal to repair, unfortunately.
Here's something to try, to see if it might be the pump shaft:
With the engine "Off", put fluid in it until it shows "Full" on the stick. Do this BEFORE you ever start the car, preferably after it has sat for a while. Once it is at the Full mark, start the car, and check the fluid again. IF the pumpshaft has twisted off, the fluid level will NOT go down with the engine running....it will stay at "Full". If the fluid level does go down when you start the engine, the pumpshaft is ok.
hth

If its the pump shaft would i have to remove the trans to replace it or is it something i can do with the trans still in the car? I am a mechanic