ok, heres the deal. the truck belongs to my dad and its a 99 4-speed 2500. its got 167xxx on it...and trans was always serviced. well my mother was driving it home yesterday and pulled into the grocerey store to pick up a few things. as she just coasted into the parking lot the thing just died on her. she started it back up...went in and did her business, and came back out. she quickly realize that the trans would not shift out of 1st gear...so she limped it back home.

now, i have searched at great lengths ALL day trying to get an idea on it...and iv pretty much come to the conclusion that its one of the speed sensors thats gone out. now my question is which one?!? i know there is teh VSS in the rear diff, then i believe there is the trans output shaft speed sensor as well (which im unsure of the EXACT location yet). now iv heard some people with the exact same problem that they replaced teh sensor in the rear diff. the i found another person with a 99 that replaced his trans output sensor. iv heard both worked for diff people.

just a lil more info everything is working fine...the spedo and tach are working perfectly. manual shifting is not doing anything. we unhooked the batteries all night and still no dice. so yeah...im needing to know exactly which speed sensor it is...cuz its used very generically on many posts. tia!

 

Sounds more like a servo or governor inside the tranny. Could be wrong though.

 

every single post (which is about a dozen) iv read on 4 different forums (including this one) said its a speed sensor issue causing it to go into limp mode. they could be wrong but every single one of them fits exactly whats going on with mine. so im goin with that idea first...i just need to know which sensor it is that i need to change (of the 2 aforementioned)

 

ok, well for those that may search in the future...the trans output shaft sensor was MY issue. cost me $25 + tax and about 5 min of my time. didnt even reset the computer, just figured her up, took her out, and she shifted like a pro!

thanks for the good info on this forum!

 

Glad to hear that it was a cheap and simple fix.

 

tx2500.....thats not the exact same problem i'm having....but close enough that i'm gonna try the $25.00 fix before i try anything else...lol....and i know exactly what you mean when you said you've been every where trying to get an answer.....and the same thing about the posts with 2 speed sensors...one will say no way, and the other will say yep it fixed it...sure appreciate your update for future lookers, cause that is me....redzone...

 

The speed sensor on the rear diff provides info for the speedometer. The one on the tranny provides info to the computer which is located on the front left of the tranny and has one plug on it with two wires.

Jason