[TheMcCoysRevenge]

I've got a 1994 GMC Sierra 1500 and in the last year or so it seems like every time it rains or gets wet the transmission shorts out and gets stuck in either 2nd or 3rd gear (cant really tell). I'm not sure if it is going into limp mode or if its something else. It will start out in first and up shift and downshift a couple times but will just randomly get stuck in a higher gear. If I try to manually put it in first after its done this the transmission whines and the truck will not move, if I turn the truck off for a minute or two it will start in first and repeat the process. Just wondering if one of ya'll could give me an idea as to where to start looking for the problem?

Thank you

 

[RayVoy]

Its probably 3rd, on the 4L60 third gear is the one where both shift solenoids are released.

Next time it's dry, and warm, crawl under and take a look at the wiring connectors, one of them may be letting get inside

 

[TheMcCoysRevenge]

Alright I will give it a look tomorrow, thank you

 

[thegawd]

Tim, if its truly going into limp mode you should get a check engine light, "i believe anyways" i know your obd1 which im not all that familiar with.... hmmmm still thinking a check engine light should lite up... i went through limp mo on my 97 burb, pita, eventually i figued out it was the ignition switch.

If it is limp mode... (check engine light, a bunch of tranny codes, stuck in 3rd but can manually shift from 1st to 3rd...) it can be is a few things..... what it essentially is, is the tranny is loosing electrical power. Could be the plug comes loose, or is all corroded, hmmmm thinking... if water is getting into the plug iand its shorting out the leads it would not put the tranny in 3rd unless the fuse blows, which should happen. The prndl fuse in the end of the dash has blown or came disconnected. The ignition switch is screwed or the wire which runs from the under dash main harness, to the ignition switch, goes to the fuse and then to the tranny, should be pink and terminates on pin e (at least on 96 and up) at the tranny has a problem, stretched broke, cut...

I dont think your problem is limp mode and rather a mechanical problem... how many mile on this tranny and has it ever ben rebuilt? What about fluid and filter? What kind of fluid is in it? I fear it may be time for a rebuild.

Al

 

[thegawd]

Oops forgot to post this.... 30 common 4l60e problems n solutions....

http://twincharlotte.com/blog/30-common-4l60e-transmission-problems-repair-charlotte-nc/

 

[TheMcCoysRevenge]

Thanks Al, Its got 181,000 miles and that I know of its never been rebuilt. As for fluid I don't really remember the brand off the top of my head, I replaced it about a year ago.

 

[TheMcCoysRevenge]

And there is no CEL and all the fuses check out