Driving home from a bout 50 miles from my house my 1999 trailblazer abs light kicked on at a slow speed which was unusual. I drive down the road some more the speedometer went bezerk and the transmission wouldnt shift past 2nd gear. Does it sound like i need a new transmission?

 

Sounds like you may have an intermittent fault in the VSS sensor. It is located at the back of the transfer case (assuming 4wd). Remove it and clean the sensor then reinstall it and see if the problem persists.

The ABS light may or may not be related. Check out the Tech Article (DIY) Index link in my signature and read through the ABS slow speed activation thread if that problem persists.

 

Hey stewart thanks for the info.. When i came home today i jacked up the truck and crawled under it and on the passenger side on top of the rear of the transfer case there was a plastic sensor i pulled that one out and cleaned it off and my problem didnt go away.. I have a feeling i might not be locating the correct sensor This is a 4wd to answer your questtion from your last post.. now when i look up the part on the advanced auto website it shows the sensor being a 2 wire sensor with a metal bracket on it.. the one i pulled today didnt have a metal bracket and looked kinda different. can you direct me to a picture or a diagram for the 4wd

I also got the code p0500 p0502 so i guess ill just go and pick up another one on pay day.. hopefully thats all it was

 

Well I removed and cleaned the existing VSS furthest back and that didnt help so i went out bought a new one and replaced it and that didnt help either. The sensor i replaced was completly plastic with a small metal sensor in the front and was 2 pin with an over shaped connector.. Did i replace the correct one? I been looking everywhere for a diagram to tell me exactly where it is .. any other suggestions?

 

The thread below shows the location for the VSS sensor on the NV233 transfer case.
Busted Tranny?

For the NV236, the VSS (4) will be in the same general area:

 

Thanks you stewart.. I replaced number 3 on that diagram.. was that the correct one? is the vss #3 ?

 

No, 4 is the VSS. 3 is the rear output speed sensor used by the TCCM for auto4wd operation.

And who is stewart...?

 

OMG im sorry i miss read your name on here.. what is your name anyway Im Neal nice to meet you and thanks you for all your help

ps i think i replaced the wrong sensor oh well 2 new sensors HAHA Yikes

 

Thanks you very much for the help! Instead of paying 3 grand to get my transmission looked at and replacing everything... I bought a 28$ VSS replaced it and now EVERYTHING works just fine!

 

I am having the same problem with my 98 bravada. what size wrench do you need to replace the VSS? On mine it is hidden on top of the transfer case