1993 chevy k3500 454 auto won't shift (Page 1/2)
jaredmurray88 FEB 03, 01:25 PM
Hey guys my brother has a dually he just had a trans rebuilt and it won't come out of limp mode. He has since gotten pissed and bought a Yukon and wants rid of the truck.. I want to buy it off of him and fix what is ailing it for a land tank. I have read that there are 2 vss sensors and if either went bad it won't move. He took it back to the place where it was worked on and they said there is nothing wrong with the trans that the computer pooped the bed. Does anybody have or have had one of these and could help me out on how to test these sensors and where they are at. Thanks in advance guys
Monkeyman FEB 03, 06:24 PM
I had the VSS go out on my old '96 Jimmy (S10 size). It went into limp mode. The gauges got all wonky, it wouldn't shift out of 2nd gear and wouldn't go over about 35mph. The shop tried numerous things before a bright mechanic just happened to think of the VSS. $130 later and it ran like new. I put another 30k miles on it before I sold it (w/171k miles). Last I heard, it's still running around (this was 7 years ago). It looks like a VSS for your truck is around $50. If it were me, I'd start with the cheapest solution and buy a couple of them.
jaredmurray88 FEB 03, 11:35 PM
I figure the vss was dropped or shocked when the shop removed the trans. I was wondering if anybody here has one and if they could tell me the resistance of a good working vss and what the input/output sensor resistance would be on the transfer case before I mess with anything. I failed to mention that the truck is still at my brothers house in pittsburg (about two hours away) so I would like to go with my guns loaded. Just before he parked the truck he put a butt load of upgrades, new parts and six new tires. If it could be a simple fix I would be immensely happy but if not than I bought a 1000 dollar parts truck that sounds like a mack truck but that's it. From what I have read the transfer case sensor gets overlooked a lot of times I guess.
mypontiac2 FEB 05, 08:41 PM
You need to check the Vss buffer. I can't remember what the year change was. The earlier models had them built into the instrument cluster, the later models had a small white box in the dash behind the glove box. I had one go bad in a 95 chevy, the only replacement I could find was in a junkyard. They are discontinued. You will have to look up on how to adjust them for your gear ratio.

Hope this helps.
jaredmurray88 MAR 18, 08:49 PM
Bump
Darth Fiero MAR 28, 06:37 PM
Your truck should have the 4L80-E auto transmission. If I remember correctly, the 4L80-E has an ISS (input shaft speed sensor) and an OSS/VSS (output/vehicle speed sensor). If there is a problem with either one, your system may go into limp mode. Also, there are a number of other problems that can cause the system to go into limp mode.

Short terminals A and B of the ALDL connector together to flash codes thru the check engine light with the key on (engine off) - just like you can do with a stock Fiero. Besides code 12, let me know what codes you get.

-ryan

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jaredmurray88 MAR 30, 11:06 PM
Hey! I haven't been on in awhile lol. There is an issue getting anything to or from the puter. No code 12 or anything at all so I got one on the way and a few things to check out in the meantime any ideas are better than where I am now.
Darth Fiero MAR 31, 04:31 PM

quote
Originally posted by jaredmurray88:

Hey! I haven't been on in awhile lol. There is an issue getting anything to or from the puter. No code 12 or anything at all so I got one on the way and a few things to check out in the meantime any ideas are better than where I am now.



If you're not getting a code 12 to flash thru the check engine light with ALDL terminals A and B shorted together with the key on (engine not running), then you certainly have a problem. You should at least get that code 12. The problem might be with the PCM itself or the wiring; it's hard to say. If the engine runs good and the only issue you are having is with the transmission, I would lean towards it being a PCM problem. But in all honesty it could also be a wiring problem. First thing you need to check is the wiring between the ALDL connector and the PCM and make sure there are no problems.
jaredmurray88 APR 02, 04:50 PM
http://www.fullsizechevy.co...-trans-issues-2.html
Here is a link to my thread on fsc
jaredmurray88 JUL 06, 09:32 PM
Well a new ecu did the the trick. Now for the front drive shaft .... WHAT BOLTS GO IN IT!!! Transfer case side with the flange. Nobody seems to know or gives a rats butt. SAE doesn't begin to fit and metric is just close enough to give you hope. The only thing that comes close is a m10 but its the wrong pitch and I have no idea what to order but an assortment and that can be a bit much for me.