1988 4runner V6 overdrive problem

[pukey]

I just purchased my 4 runner and realized that its not shifting into overdrive. the OD button will turn on and off the light on the dash but the trans isn't shifting gears. Has anyone had this problem and know the fix?

 

[TSP-MIKE]

Sounds like you have a bad connection to one of the solenoids on the transmission, or a bad solenoid. The computer shifts through all the gears, so check the wires from the ECU to the trans. and if it's all good, it's prob a bad solenoid.

Mike

 

[pukey]

where is the ECU and is there a seperate one just for the trans?

I heard about it being a solenoid that controls that and I figured it could be "sticky". The car sat for atleast a month before I bought it. So on wednesday while I was driving I would press the button on&off when ever I hit some bumps on the freeway, and it ended up working. I didn't drive very far with it while it was working but the next time I went somewhere its not working again and the light on the dash (wich was working before) has also stoped working.
My thought is: if the solenoid is old and "sticky" it may draw more current and the fuse my have blown. I checked the fuses under the dash and hood and didn't see anything labled ECT or anything that sounded specific for the trans.

Has anyone had to make these repairs before? If so does anyone know the wire color, location, conector shape, anything like that?

 

[pukey]

what other yotas have the same trans as the 88 4runner V6?

 

[TSP-MIKE]

Finally back to my Computer! Alright there are 3 wires that you need to locate comming out of your ECT ECU, and Trans.
---ECU Side------------------------Trans. Side
1. pin # 10 Yellow------------------Yellow
2. pin # 11 Black/Yellow-------------Black
3. pin # 12 White-------------------White

locate these wires and test them to see if there is a break in the wire somewhere. The Trans. wires should be on the drivers side of the trans. and should go down into the trans. It's by the front of the trans pan.

Check these wires and if one of them has a break then that's your problem! If not then one of your solenoids are bad in the transmission and may need replacing.

Note: Your ECT ECU is seperate from your Engine ECU.

Hope this helps!

Mike

 

[pukey]

Thank you, Thank you!!!
Where is the ECT ECU? I figured somewhere in the dash but haven't started following the wires yet.
I take it the Solenoid is inside the trans?

 

[TSP-MIKE]

The ECT ECU is probably next to the Engine ECU. The ECT ECU wires should run into the engine harness along with the Engine ECU.

Yes the solenoids are in the transmission!

Mike

 

[pukey]

I heard somewhere that if the engine isn't warm or the ECU doesn't think it is it won't use OD. This sounded feasable to me since the last time I got it to go into OD it as pretty warm out and typicaly it takes over 8 miles on the freeway before my temp gauge starts to go up, but I get warm air rightaway, so I'd bet my therostat is open. whacha think?

 

[TSP-MIKE]

That is true! This happend to my 4runner, All i did was replace the thermostat with a new TOYOTA one. That fixed my problem. I didn't notice that you lived up north.

So try replacing your new thermostat and make sure you have the correct amount of coolant in the system. If that doesn't work then trace the trans. wires.

Mike

 

[pukey]

Yep, in michigan. I had a 85 and 86 pickup before, both manuals, but I just joined this forum since I bought the 4 runner so I haven't realy set up my account yet. I have a nice photo of my 85 about 5-6 feet off the ground I need to scan.
I'll be a happy camper if thats all I have to do! I'll let you know on Monday. Thank you very much for all the info!