4wd Actuator Issues

Ill start by saying if this is in the wrong place please advise and I'll move it.

2017 TRD OR

I'm getting the dreaded "blinking green 4wd" issue. I've removed and checked the ADD and soldered its motor contacts. I will say it looked rough (had water inside, rust, etc) i cleaned it up best i could then bench tested the motor which ran fine. And I'm "pretty sure" its timed correctly on the position sensors.

I reinstalled and all work well for 2 cycles (2hi-4hi-4lo and back) then it was back to blinking and not responding to the dial.

Here's where it gets weird. Currently, when shifting from 2 to 4hi it continues blinking (green 4wd light) but the transfer case IS engaging 4hi AND and ADD is engaging as well. But its like the truck doesn't know its in 4wd.

I then have to put the truck in neutral, turn it off, turn dial to 2wd and when I restart the truck it disengages the case and ADD back to 2wd and the 4wd light goes off.

Could my issue still be in the ADD? Is it maybe not reading its position correctly? I've also read through this thread
https://www.tacomaworld.com/threads/4wd-actuator-troubleshooting-transfer-case-and-add.578262/
but not sure where to go from here.

 

How deep of water did you get in to?

 

I haven't directly, the water looked old and nasty, I guessing a couple years of it leaking.

 

Sounds like a feedback sensor or limit switch is not telling the truck the ADD has completed its operation. I’m not familiar enough with the internals to say what to do about it, but that would be my best guess.

The trucks electronics are asking for all the right things to happen, which they are, but is not getting the “all is well” signal back from the ADD actuator to confirm it has completed its operation.

 

Wasnt FULL of water but had some

 

Ya I'm thinking I may need to take another look at the ADD

 

I’m not sure if it’s a classic limit switch, or a modern proximity type sensor, but something in there has to signal back that the operation is complete. Maybe someone who knows more about the internals than me will chime in.

Good luck. Let us know if you get it figured.

 

2G taco info, but might be helpful if it’s the same or similar.

https://www.tacomaworld.com/threads/tacoma-add-delete-wiring-figured-out.464595/

 

Yup , the 2G taco info works for the 3G taco as well
You 3G owners need to build some write up,s with pictures .
https://www.tacomaworld.com/threads/transfer-case-transfer-cases-in-first-and-2nd-gen-trucks.345652/

 

To troubleshoot further, you will need Techstream or an ohmmeter (and feel comfortable enough to use it).

From your description, its 95% likely to be in the front ADD or the wires/connectors to it.

If you use techstream, in the 4wd system you will be able to check which feedback signal is nonconforming to the table (when going to 4hi).
If you use an ohmmeter, i would shift into 4hi (and cause the blinking) and then shut down. Pull the ADD connector and check the ohms from Pin 4 to Pin 3, Pin 4 to Pin 5, Pin 4 to Pin 6.
(on the actuator side).

Note, I think this figure shows the truck side of the connector, so your pin #s will be opposite.




If any of the three pins dont give feedback matching the table the system will throw a code. If its just a mild blinking without hard instantaneous codes, I would bet the failure is on Pin 6 so it doesnt realize it has gone to 4wd, (but not sure).

If it doesnt match, then have to remove and rework or remove and replace...

That is all I have for general suggestions.

 

thanks man!

 

When using the meter oh ohms what reading am I looking for to show GND/OPEN? Im assuming GND should show somewhere around .5 Ohms and open should be zero?

 

depends on the meter

hold the probes together and see what it reads (typically will be about 0.5 ohms)
hold them in the air without touching any metal on the probe and see what it reads (typically a flashing zero in the largest significant digit or some other way to show out of range)

 

thank you, I just tested, shifted to 4wd and 4-6 showed open 4-5 showed closed 4-3 showed open (should be closed) looks like i need a new front actuator. Thanks again BigWhiteTRD

 

Dealt with this on a buddies truck recently. The ADD detection switch is not being made in the ADD unit. So the 4WD ECU doesnt know its locked in, even though physically it is and will work normally (just no 4Lo).

Water and other stuff has made its way inside the switch and the little fingers cant make contact or only make contact sometimes. You can gently pop the black cover off the switch with a very small flat blade. The rocker and metallic contact 'fingers' will pop out. You can try cleaning and drying them really well and putting everything back together with some DeOxIt. Unfortunately that hasnt worked too good for us on my buddies truck. He still gets issues from time to time and just ended up ordering a new actuator. To be fair I think his had water in it for a long time, so the motor and limits switches were also suspect.


See attached pictures

 

Just read through the whole thread during lunch. Looks like @BigWhiteTRD and @Stocklocker nailed it.

Hopefully my pictures help you troubleshoot further and possibly avoid spending several hundred $$

As a side note OP you may or may not know that the ADD breather is rubber, then a short hard line on top of the clamshell, then back to rubber the rest of the way up into the engine bay. (terrible design IMO). Id bet the interface between that hard line is where the water is getting in.

 

Thank You!

 

New actuator will be here tomorrow.

 

That fix it?

 

Ouch, I gotta say...since it has a gasket of sorts I wonder how on earth does water make it in there.

I 'seem' to see a lot of these actuators fail because water gets in there and it makes me wonder if I should do some preventative things so I don't run into this down the line.