Flashing overdrive light

[tbkilb01]

The Overdrive light started flashing on and off and the cruise control stopped working as well. I checked code and is showing 42... Wondering if its okay to run Previa with bad sensor? I checked wiring, it's good. Tranny shifts same as before. Goes in and out of OD as needed and on demand by using button on shifter. I Unscrewed the no.1 speed sensor and tried to test it but its so small that its not a easy test. I replaced it. It's easy access and I plan on driving to bone yard to get a couple. I use Previa as DD. wondering if i should park Previa to avoid damage to tranny? :?:

I even pulled transmission water temperature sensor just to test it and replaced it. Code still pops ups after resetting and driving. Guess it's off to get parts on day off..:drive:

[cvtroger]

I didn't have that issue, but you can call a transmission shop and see what they say. Maybe the gear is going out?

[tbkilb01]

I Just noticed the odometer's not working last night. The
speedometer went out a while back but the odometer was still counting. I guess I'll dive into the FSM in my spare time. I'll pull speedometer cable out of pull it parts too when I go this week to grab sensors on tranny. Could all this be from code 42? I guess I'll not drive Previa to avoid further problems. The tranny is working fine though, it's responding normally to driving demand. I'm hoping it's something simple. :cnfsd:

[tbkilb01]

I went to the boneyard yesterday and found the No.1 Speed Sensor on a 91. This 91 previa really paid it's dues! The odometer showed 492000. The owner apparently used it as a work vehicle. It seems he was a carpenter and even had a shop light mounted in the back where he worked..Not just a regular light but a long double florescent type used in garages etc. He pulled the back seat out to get more space to work. When I pulled the VSS out of my 92, I noticed the gears were all wore down. I put in the 91 VSS and reset the codes. I went around the block to test the Speed Sensor out. Well, code 42 no longer pops up, the overdrive light stopped flashing and the odometer works again. The cruise control also started working perfectly again. But the speedometer still is not working. I guess it's fried, maybe I'll pull one out of boneyard later or do like The Man says and check capacitors. At least I feel better now about the transmission/flashing overdrive light/ECU working. The Transmission never was really effected by this No.1 Speed Sensor failure that I could tell, but the odometer and the cruise control were. The flashing OD light just that made me uncomfortable. And it wasnt so much the sensor that failed, but the plastic teeth on the gear (located on the part of the sensor that goes into the transmission) that wore down!

[tbkilb01]

Well, I finally got around to pulling out the instrument cluster from the 91 Previa that I previously removed the VSS from. They only charged me $20. I was under the impression that it had an actual speedo cable. When I removed the speedometer Cluster I found there was no cable connecting to speedometer! It's all electronic.:dizzy: . Just plug and go. Well
I then proceeded to pull out my 92 cluster and I noticed the connection's in back are different. I plugged them in anyway thinking something would work and not!!:doh: So i replaced mine. As soon as the rain stops down here I will return to the boneyard to grab a cluster out of a 92 they have and exchange them. I wonder how many other parts off a 91 will not fit on a 92?

[tbkilb01]

Well just put in a different 1992 speedometer cluster in and it only registers half the speed im going.
I guess l'll revisit the wiring and the vehicle speed sensor #1.
Wondering what is speed sensor #2 for? :cnfsd:
Well I replaced my original VSS #1 and the IC still reads about 1/2 speed... Maybe low tranny fluid?The wiring looks good and connections are solid. I just cant put my put my finger in it.:(:
I use a GPS for now. Any ideas?

[tbkilb01]

I got my hands on the wiring to the VSS that connects the VSS to the harness. Even pulled another VSS. Swapped them all out-again and still no go on speedometer. I guess it's time to swap out the Computer. I just got to find a donor vehicle at bone yard. 91 had no air bags, at some point a passenger air bag was added after 1992...So I guess it's either 92 or 93 version? Does computer send speed from VSS to speedometer ?

[timsrv]

http://www.toyotavantech.com/forum/showthread.php?1549-90-99-Previa-speedometer-repair

[tbkilb01]

Yea, thanks Tim I remember looking at that post a while back but I decided that that route is above my pay grade,at the moment...I did swap out the original instrument cluster with another cluster out of a 92 and got same results. Returned it when it made no difference...it was still reading 1/2 speed. I reinstalled my original one and its reads no more than 15 MPH. What are the odds of both having bad diodes/resistors? Anywho, maybe the ECU recieves the signal from the sensor first and then sends the speed to speedometer?
Im waiting for another van in the boneyard to try a third one..and pull the ECU. They are thinned out around here lately. That ole crusher sure eats em up!