View Full Version : 4t80e problems

05-28-08, 10:25 AM
First time user, I have a 94 STS seville, Northstar, I am getting a consistent error set, P117 which refers to the shift a and b sol. in the trans. fortunately I have access to All data, and have the diagnostic procedure to troubleshoot this code. Unfortunatley ALLData assumes you know more than the basic diagnostic techniques, and only give you the how to use the ECC panel, It does not tell you how to access the various tests called out in the diag. procedures from alldata. does anyone know where I can obtain a manual that explains the diag. procedure better. Also about the same time the fuel gage started acting weird, it is as if the dampening is not working, when you hit a bump, or when you turn the needle moves quickly..... Thanks in advance


05-28-08, 04:11 PM
Get a factory service manual by Helm Inc. Ebay is your friend. Shift solenoids where a common problem on the early 90's. No need to trouble shoot any further. Just change them both and be sure to use the strap that comes with it. Yours won't have one on it.

05-28-08, 11:03 PM
Yup, what he said ^^^

05-29-08, 03:25 PM
Thanks all, I am gettng the manual as we plan on keeping the car for while, and talking to other caddy gurus the said the same thing... so I guess now I need a shift solenoid kit, any suggestions, the local caddy guy has them but I am sure there is a source on the net... any help there is appreciated.


05-29-08, 05:34 PM
Lindsay Cadillac on the right side. Ask for Luke and tell him you're from here >>>>>>>>

05-31-08, 02:03 PM
found the gm solenoid kit rite here in river city (ft. myers fla.), transmission partsusa.com, they had the kit for 61.00 with tax and shipping. the manual I am getting on cd, thought I would give it a try first, it was 13.00 plus shipping, comes from autorepairinfo.org. one last question, I see that there is a drain plug for the side cover under the pan, as I will have the pan off to repair the solenoids, I should change the fluid as well, thanks again for all the help, I have a few other issues, but hopefully the manual will get me through them, if I need further advice at least I know I have some good friends here. thanks again


05-31-08, 07:40 PM
As long as you are there, you may as well do a fluid change. I would.

06-02-08, 03:25 PM
that is definately on my list, any pointers on replacing the solenoids, it looks pretty straightforward, but you never know what devils lurk within... (smile).

06-02-08, 04:17 PM
Do a search. Tech Tips section may have tutorial. I know I saw one some time ago.

06-02-08, 06:07 PM
thanks Ranger


06-28-08, 03:53 PM
HI there!

I have the same problem on my caddy. Can anyone explain me the exact procedure to solve this issue? (P117 DCT).

Kind Regards!
Carlos Blancarte.--

01-29-09, 10:29 PM
Well, I am back with a new problem related to the 4t80e box, now after it warms up good the shifting becomes erratic, looking at the data from the pressure sw. it too is erratic. The lines x,y,z from the trans to the pcm are monitored on pd71 (at least that is my take)... anyway when cold for the first 10 mins or so all is well.. then the trans begins to shift erratic, sometimes dropping in to 2nd gear only, sometimes jumping around, sometimes all is well, when in the diagnostics looking at ECC the "ECON" lite flickers, and sometimes dims.... maybe that is my imagination.... I am thinking that the problem may be the pcm is heat sensitive, I somehow don't think the pressure switch is heat sensitive.... I have tried wiggling the connector on the pcm, and the connector on the range switch.....hmmmmm any advice is appreciated... I have learned alot about the northstar system but have soooooo much more to learn... will be looking for any advice..



01-30-09, 03:14 PM
Check your fluid level - hot - on a level surface - at idle

01-30-09, 06:34 PM
I feel for ya. I had a sim prob, My solonid was broken. I replaced them with the kit from GM. still no good. when I dropped the pan the 1st time there was a ball and some gasket material. I replaced the valve body, problem solved. That was 3 months ago. It was perfect. I got the valve body from an olds trans. same trans. $80. Eb*y

Now im cruising along and it's slippin like mad and won't go into lockup. Third is very irratic. 1st and 2nd are fine. I did pop the TCC code a couple times. I just dropped the pan tonight and didn't see anything. I will drive it on Monday and repost.

"I'll never give up my Crappillac":thepan:

01-30-09, 06:44 PM
fluid check was the first thing I did, it defineately seems to temp. related.... we have a cool snap here in Sw fla.. took almost 45 mins of driving this morning before it acted up,,,,,,