4wd System Operation & Help Thread

Did you test your meter at the battery to see if it's accurate? I find it odd that your getting 7-8v on everything unless you had a bad ground on your meter.

If your meter is indeed off it looks like either the Transfer Case Actuator is mis-timed or there's an issue with the 4wd detection switch or circuit.

 

I tested the volt meter off the battery (13.8v). I even used jumper cables to ground it off the battery.

 

So you show 12v at the battery on your meter?

 

13.8v at the battery is what my meter is reading.

 

Interesting, I haven't seen anyone have voltages that low on the 4wd limit switches but it appears the 4wd ECU is seeing them properly.
The 4wd detection switch doesn't appear to be closing so I'm suspecting either the actuator is out of time , the switch is faulty, or a wire is broken/corroded.
Actuator being out of time seems most likely since you had it off.

 

Alright I'm gonna try timing the new TC actuator and see if that works.

 

Remember the contacts have to line up with the switch plate as shown depending on what position the transfer case is in.

 

Tried 4 different positions with no luck!

 

First make sure the Transfer Case is in 2wd by rotating the gear as far counterclockwise as it will go then line up the contacts so they match the 2wd position on the cover.

 

Guy: Even though I'm not having even a hint of a problem with my Tacoma 4x4 system at this time: I have to check in once in a while
just to say: when it comes to this complex system:

You're BATMAN! Thank you!

 

those voltages are right out of the ECU so I wonder if the fuse isn’t in tight or a loose connector to that supplies the positive voltage to the ECU

 

Good point, I saw it looked like it was at least trying to move the actuator so I didn't think much of it.
F12 Pin 5 (Violet) is the power wire at the 4wd ECU, may want to check voltage there.

 

5th time was the charm! Thank you very much! Was about to throw the whole truck away

Also watched this video to help with positioning for anyone else that might need it.

https://youtube.com/watch?v=FnsUs_LO-x0&feature=shares

 

Nice, still curious about the low voltage on the switch circuits but if it's working no need to worry about it I guess.

 

Anyone know why, very intermittently (maybe once per month, if that), the 4WD light would turn on momentarily when starting the truck in 2WD? Started happening maybe 6 or 7 months ago.

 

Can't say I've seen that before, does it flash a couple times and then go out or is it just on once and off?

 

Just once. Basically flicks on momentarily and then off.

 

That's interesting, not sure what would cause that unless one of the actuators is getting water in it from a broken vent hose.
Does your 4wd still work?

 

Works perfectly fine in both high and low.

 

I only joined the forum to say this post saved my marriage and quite possibly my life. Had it not been for Dm93 putting this together and others who have contributed, I would've had to put off starting our new house. Which most likely would've ended with my wife having my head mounted on her new mantle cause she'd get more through my death than divorce.

I was very close to scrapping the entire 4WD system for an SAS (cause I have the majority of the parts already) and paying out the nose for a custom adapter to install a 4 speed manual t-case.

My issue was the t-case actuator. Hose came undone and water infiltrated. Was able to clean and add some solder on the 2WD circuit. Reckon I caught it early enough to salvage.