No speedometre and truck wont shift out of 1st

[duramaxdude]

I was driving along in my truck today with the cruise control on when my speedometre suddeny dropped to zero and my truck downshifted right into first gear. I have no codes except for the usual Egr codes 32 33 44 45. And codes 61 and 62. The Abs light also came on.


so i had to limp my truck home in first gear now ive been trying to figure this out. a month ago I had code 16 Vehicle Speed Sensor Buffer Fault. Is it possible that my speed sensor suddenly went. I didnt think it would go just driving down the road but im not sure.

also when i would rev it up the speedo would come up a bit to about twenty and it seemed like it would try and shift but as soon as the speedo went down again it just stayed in first.

what do you guys think has anybody else had this happen to them?

thanks for any help.

 

[THEFERMANATOR]

The speedo going up when you rev it is completely normal, even the 01-02 DMAX's do this. It is a backfeed inside the cluster I believe. As for the no speedo and only 1st, you need to find out if your VSS(sensor in the tail housing of teh transfer case) is bad, if your VSSB has failed, or if the wiring to either is bad. The ABS light coming on also fits with this. Make sure your fuses are good first because if teh VSSB loses power it will quit sending out a speed signal, but the lack of codes sounds like a speed sensor problem to me as I would expect your code 16 again if it was the VSSB.

 

[Acesneights1]

Yep, my old Tahoe did that and it was the VSS

 

[Riddle_3d]

i had a 94 suburban do this to me. gave me absolute fits for months. 2 new VSS's, eventually gave up on it. it might have been the VSSb, looking back on it now

 

[duramaxdude]

Thanks for your help guys. How do i go about testing the vss. I will try and get a new one tomorrow morning as soon as possible.

 

[duramaxdude]

Acesneights1 did your vss just quit on you as you were driving?

 

[buddy]

check the brake fuse, or any other similar fuses

 

[bison]

Thanks for your help guys. How do i go about testing the vss. I will try and get a new one tomorrow morning as soon as possible.

It should test over 20 OMhs.Test both,they should be within a couple OMhs from each other

 

[bk95td]

Check main tranny connector for oil contamination. Power supply to tranny is suspect also. A scan tool would tell you what the sensors are reading and ecm is seeing.

 

[duramaxdude]

well i got it fixed this morning. I had a bunch of snow build up around the vss and it turned into ice. The chunk of ice came loose and pulled the vss conector right out of the vss on the fly. had me worried im glad it was only that. | guess i'll have to let my truck thaw out for a few days now or something before anything else weird happens.