raptor510

Hey guys!
First time poster here looking for some help before he pushes his rig off a cliff.

Speedometer, odometer, and trip counter all went out about a week ago. For a few days speedometer would kick in for a few miles and then nothing. Drove it a few more days then noticed the O/D Off light was blinking. Follwed some great write ups on here and learned it was code 42 - speed sensor 1(VSS1). Replaced the speed sensor with a brand new one and no change at all. Put my original one back in today but have not driven her yet. I expect that she will still not be happy.

If it isn't the VSS being bad, what else could be causing this? The wiring harness looks great, no corrosion on the terminals, not experiencing ANY of the transmission issues others have reported, and I have pulled the negative off the battery overnight to clear the ECU but nothing changes.

Help a brother out, please, oh great and knowledgeable brethren!

scope103

4wd? Year? Model? Transmission?

Code 42 is usually VSS-2 . VSS-2 measures the speed of the transmission, and is used for shifting.

But that won't do you any good for a speedometer, because the intervening transfer case can change the gear ratio. So the speedo (odo, cruise) run off VSS-1. Your symptoms are the classic sign of a VSS-1 problem.

Or, maybe you don't have 4wd. But you never told us anything ....

raptor510

My bad, was in a hurry. It's a 1994, 4wd, auto.
So the weirdness continues. Like I said before I put the original sensor back in and was able to drive it just now.
Totally works! Could it have been nothing more than a loose connection? Hard to imagine considering the wire harness clips in so tight?

scope103

The VSS1 dies a little bit at a time. The symptom I had (and I've heard from others) is that everything would be fine, then the speedometer would drop to zero for a few seconds, then pop back up. Over time, it stayed at zero longer and longer until I replaced VSS1.

raptor510

I read that as well. I thought about the chain of events and while I have no clear indication as to what happened, I can only wonder if somehow the wiring harness was in fact just loose enough to cause the issue, OR, if the ECU just had a brain fart and when I reset it with the original sensor reseated it automagically healed itself?
Nontheless, I am hoping for the best but am keeping an eye on it. When I drove it yesterday, I drove and parked at 3 different places while running errands and it was all good!

raptor510

So I was wondering the other day why the new VSS1 didn't work but when I put put the original one back in it did work. I'm still perplexed. Been driving it every couple days and all seems fine. Yesterday for about 2 minutes when I started her up the speedo was not working but then it sprang to life and was fine since then. I hope it stays put as I have already returned the sensor I bought!

scope103

As I said, you still have the classic symptoms of a slowly dying VSS1. At least you know how to replace it.

Though why it didn't work with the new one is a mystery. In my part of the woods, you can never return an electrical component. The vendor doesn't know if I'm actually returning the bad one. Since your vendor apparently allows returns, perhaps that happened to you?

raptor510

Hey scope103! I'm back with more weirdness. Since we spoke I put my original sensor back in and waited for it to finally die for good. I ordered a brand new sealed and still in its bag vss1 and just put it in. Drove down my driveway and NOTHING. speedo still not budging. Tripped te1 and e1 to see if I had any codes...none. Wth? 2 sensors couldn't be bad could they? If its not the sensor what on earth could it be? The truck still drives perfectly fine and I've not had any of the tranny issues other members have reported so I'm left at square one more frustrated than ever. Anybody have any ideas? At this point I'm about to give up and take it to the shop to let me figure it out.

scope103

My money is on a wiring problem.

If you're electrically savvy, this section http://web.archive.org/web/201008021...e/combinat.pdf shows how to test VSS1 (don't lose this page; let's just say it's rare).

If you're really electrically savvy, you can hook a signal generator up to the wire back to the combination meter, and "simulate" VSS1 to see if the speedo works.

Short of all that, you can ohm out the wires from the transfer case up the combo meter. Not technically difficult, but time-consuming.

Terrys87

iTrader: (1)

I have not had to work on VSS, but in general, alot of these connections get corrosion on them. If possible try cleaning the contacts. I now give all of my electrical contacts a coating with Dielectric grease to help with a better connection and help prevent corrosion.

raptor510

Hey guys!
So while all of us were on the right track, I just got the truck back from my mechanic who got his electrical tester out and after 30 minutes and a few phone calls to his contacts he diagnosed it as a bad instrument cluster. I thought that sounded weird till his friend (a mechanic at a yota dealership) told him that he's had 8 4runners with the exact issue as mine - replaced VSS1, ECM, checked wiring etc until they popped in new instrument clusters. Bingo - problem solved.
I've called a company that will come to me on monday and will repair the entire panel for $200 or less. fingers crossed that fixes it! i'll let you guys know.