Overdrive issues

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Originally Posted by Cornato

That's what I'm saying!!! But there is so much more work I have to do!!!

Replace the thermostat
Rebuild the p/s pump and res
Change spark plugs and ign wires

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It can be time consuming... especially if you are new to working on TV's. Think of it as time well spent getting to know your van. Like spending time with a new girlfriend. The more attention and affection you give your van the more it gives back... neglect it and it will soon be gone.

The more time you spend under the hood, the more you will find to do... don't be surprised if that initial list multiplies by a factor of 4 or 5 before you get it all done.

Oh... if you are doing plugs & wires it's a good time to do cap & rotor. Also if you get your PS pump working don't be surprised if some leaks crop up in a few months... you may want to do hoses while your at it. Same re: the thermostat... good time to do rad hoses.

See... even more opportunity to lavish love and affection on your van.

-Jim

I'm gonna need to get a second job. Dammit.

FWIW, my overdrive has always worked fine. I don't have any overdrive light indicator on my dash and didn't know there was one until just recently...

Light bulb burned out back there? I'm not going to try and fix it though.

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Originally Posted by timsrv

Before starting new threads please search and post in one that deals with the subject :). If none exist, then by all means start a new one. Here's a good one. Hope this helps: http://www.toyotavantech.com/forum/s...erdrive-issues

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OK I read the thread and you state here,
"Note: the 4wd van has a slightly different / more complicated OD system, but since yours is a 2wd we'll stick to 2wd for the sake of this discussion."

Do I still follow tips and advice? Not sure if it matters or not, but my indicator light on the dash does come on when pressed. Good thread though, and you do a remarkable job of explaining things! I do some searching for threads tomorrow. At least I know that I'm not getting OverDrive on the road.

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Originally Posted by User1

Do I still follow tips and advice? Not sure if it matters or not, but my indicator light on the dash does come on when pressed. Good thread though, and you do a remarkable job of explaining things! I do some searching for threads tomorrow. At least I know that I'm not getting OverDrive on the road.

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Sorry about being a pest on where to post. It's all about organization (future searches, etc). I went ahead and moved your post here. Yes, there are some differences in the 4wd vans, but the systems are similar enough to be lumped together. The big difference with the 4wd is a temperature sensor, overtemp indicator light, and the OD relay is a bit more complicated inside (on the 4wd they call it "ATM Control Computer"). Everything else still applies. The 1st thing I'd do is pull the wire off the thermo switch that's located at the front right of the cylinder head (use the picture shown earlier in this thread). If it starts shifting into OD, then the thermo switch is bad. Your choice on whether or not to replace it. I've been driving my van for years without the thermo switch because I wanted the port for a temperature gauge. The only downside I could see is I have overdrive before the van warms up......oh wait.........is that a downside??? :?:

PS: The temperature sensor on the 4wd transmission (different from the thermo switch on the head) talks directly to the transmission computer. If an overtemp condition is detected the computer will lock out overdrive and illuminate a warning light in your instrument cluster. Sine you're not reporting an overtemp warning light I doubt it's that sensor, but I suppose it's possible the bulb burned out or maybe somebody removed it..........but that's a bit unlikely.

http://i8.photobucket.com/albums/a23...ps2ad8f475.jpg

Hey everyone, I'm in the process of taking this floor panel out from under the passenger seat. How entailed is it to take the shift panel off of this thing? Will I still be able to drive it? What I was hoping I can do is take this to the carwash and get the engine compartment cleaned. That is I'm assuming I can use the first three gears(auto). Figured I'd tried to make the process a bit more useful by cleaning up in there I was planning on disconnecting the OD temp sensor to see if I can get my OD to work. It's pretty grimy and tried to grab and pull back on it. Not sure if you need to twist it or what. How does that connector come off? Man really wana just cut that wire!

There's a link to instructions for removing this panel in my 1st post on this thread. You leave the shifter on the panel and just move the entire assembly to the back seat area. The shifter cable will flex enough to move it out of your way. Toyota uses little locking mechanisms on most of their wire connectors, so you usually have to do something special to remove them (some are worse than others). I believe the OD thermo switch connector requires you to squeeze it in a specific spot to release. Just use a flashlight and it should become obvious where to apply pressure.

For test drives or trips to the car wash I would put the panel on with just a couple of screws. Just don't leave it that way for extended driving. Not only is this panel designed to keep noxious fumes out of the cabin, but it's also a structural piece (not something you'd want loose in a collision). Have fun at the car wash. Be sure to bring tools to remove your distributor cap........because if you get water in there it will run like crap (if it runs at all). Tim

OK I wana get back into fixing this OD problem I'm having. I'll list just about all the the steps listed above and status and then I'll state what is happening. BTW, I also read the Sensors to overdrive thread.

*Checked the 7.5 amp(?) fuse and doesn't look burnt, but there is my gas gauge not working correctly. If there's a full tank
of gas, then it works correctly. Anything less, and it reads empty. All other gauges and lights seem to be working.
*OD light does come on if button is pressed
*Thermo switch is discounted
*I have not checked the harness connection that goes to the solenoid. I have not disconnected it and verify the conductors inside are clean and shiny.
*Did check the wires under the center console of the van and all the wires look good. Can take pics if needed.

When the thermo switch was connected, I did have the van going into OD once in a blue moon. Ever since I've discounted the Thermo Switch it has yet to go into OD. I could try and get it to go into OD when it's half way warmed up, or all the way warmed up and still no OD.

HOLLY COW I HAD MY OD WORKING TODAY!!!!!! :dance2:

Man that's nice going 70 mph and barely getting to 3000 rpms!!! I'm not really all that good at listening to my van but I think she was telling me she wanted to go to Alaska!!! I filled the tank, actually I topped it off. It had quite abit of gas in it already. I put in about $20 or 5 gallons. After it was filled all the way, the gas gauge read a full tank and van started shifting into OD. I had to stop by a store and then I got on the freeway. I started on the freeway and was thinking I had just 3 gears. Then this panel TV passed us up in the fast lane and she shifted into OD on the freeway!!! Oh wish I was heading north. It didn't even start overheating till the panel van was just a little dot in the horizon and we were almost home. The girl had so much desire in her! :shock:

Man my OD is showing some life! Today is the first day I've gotten into my van TWICE and had the OD working both times I got in! Usually it will work once sometime during the day, and as long as I'm driving it will shift into OD when needed. But if I stopped and stopped the engine, that would be the end of OD for the day. Today was different! I had OD working, I stopped and when I got back into the van to drive, it started shifting again into OD! TWO times in a row!!!!!!!

I got a chance tomorrow to check the harness connection that goes to the solenoid. Just to get that on the list of "done that".

Oh and no complaints with the shifting, seems to shift great when it's using four gears.

Okay, so I checked the overdrive solenoid. Applied 12V to it and I could hear it activate. Drive it around a bit and overdrive didn't kick in (Before I did a mess of work the O/D would kick on after like 30 minutes on the freeway). I checked the hookup for the O/D solenoid and at operating temperature is was putting out a little more than 12v which would activate the solenoid right? But no O/D still.

The O/D black box felt hot to the touch while driving. Also while looking at it there was one yellow wire with a solid red stripe tucked back into the harness, I pulled it out but I doubt it hooks up to anything. Looks like the factory tucked it in there.

Also under the center console there was another cluster of wires with a connection on the end that isn't hooked up to anything and I can't find anything it hooks up to.

So tests done thus far

O/D Solenoid Good
Solenoid connection Good
Temp sensor (didn't change O/D Issue when disconnected.)
all I can think of is the Relay which is heating up and Toyota doesn't make it anymore
Or the ATF thermo sensor which is 4wd specific and I can't seem to locate.

The ATM control is wired different on the 89 than on the 87 in the manual so i don't know how to test it, if anyone can scan that page mad props.

http://i1089.photobucket.com/albums/...g/0badb2af.jpg
pic of the extra wire and hookup, Thanks!

Hey Tim, I have read all the overdrive posts on this forum and toyotavanpeople which are quite informative but have not resolved my issue.

None of thos threads are 4wd specific and I have trouble shot the the simple circuit of thermo switch and solenoid and am getting no response now.

Now that the thermo switch is disconnected I can hear the solenoid engage and disengage by the press of the button.

I am going to take it for a long drive now to see if the O/D will engage after a while like it did before, but it does not readily engage

No dice. The day before I had added some seafoam trans tune (which worked wonders on my 2wd drive van). When I checked the fluid level it was wayyyyyy too full. Like while cold the level was 1 inch over the hot max mark. So I drained the fluid down to the right level and with high hopes I hit the road.

80 miles later and no O/D. Next step is draining the fluid and changing the filter.

Going to unhook the relay and see if the solenoid still clicks. If not than maybe the relay is good.

Then check all the fusible links.

Then set it on fire and push it off a mountain

::D

Good luck. I haven't yet experienced the type of failure you're having. I've dealt with non-working overdrive circuits a few times but each time it was a simple fix. Right now we're in the middle of a move & I don't have much time to monitor the forum and respond (sorry). The best advice I can give is to follow the factory service manual and study the schematics. Please share the solution with us once you find it......and if you're persistent, I'm sure you will :yes:. Tim

O/D is working!

Flushed tranny, changed filter, filled it and added lucas oil. jumpd on the freeway and O/D has worked perfectly since!

Hi,

I recently bought a 2wd '86 Van w/ 124k original miles and it hasn't kicked into overdrive yet. I disconnected the thermo switch and pulled the solenoid and tested the continuity between contacts and it checked out fine. Still no overdrive. The thermo switch just needs to be unplugged at the connection, and not pulled off the senor completely, right? I didn't want to remove the passenger seat and was able to unplug it w/ a long pair of pliers.


Also, it seems to change gears late. For instance, I have to let off the gas a little at about 37-40mph to get it to kick into 3rd gear. I checked the throttle cable adjustments per the manual and it appears to be dead on. Could this have anything to do w/ my overdrive issue?

One last thing, I'm getting about 17mpg...after a tuneup. Any easy way to improve this? I've heard a bad throttle position sensor may help.

This is a great forum and great resource. Thanks for reading!

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Originally Posted by masterace

I didn't want to remove the passenger seat and was able to unplug it w/ a long pair of pliers.

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I find this statement interesting. How did you manage to release the locking clip of this connector? Are you sure you didn't just un-plug the temp gauge sender? The OD Thermo Switch is the one with the gray connector under the gauge sender. IMHO the passenger seat cowing needs to come off in order to articulate the plastic lock & remove that connector.

You don't pull the switch from the head, you simply pull the gray connector off of it. If the problem is due to a faulty thermo switch the OD will begin working. Tim

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Originally Posted by timsrv

I find this statement interesting. How did you manage to release the locking clip of this connector? Are you sure you didn't just un-plug the temp gauge sender? The OD Thermo Switch is the one with the gray connector under the gauge sender. IMHO the passenger seat cowing needs to come off in order to articulate the plastic lock & remove that connector.

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Maybe I could drive up to Battle Ground and show you :bluevan:

I am fairly certain i pulled the right plug. Its the one directly below the gauge sender just like in your picture...plus my temp gauge still works fine. I grabbed the plug with a really long pair of needle nose and it separated easily. I then moved the metal clip that is directly behind it to move the plug out of the way.

The plug on my van was actually blue...

Hello! My Van's heat doesn't get hot at all and I've been lead to believe that this could be related to the fact that my OVERDRIVE is no longer kicking into gear. I followed all the steps in this fabulous post but to no avail.
Anyone have any experience with this little quirk?
Thanks in advance!

So you disconnected the OD thermo switch?