4wd issue

Took my 06 Tacoma up a logging road to go snowmobiling yesterday, 4wd was working fine. Before I hit pavement, turned 4wd off, both my hi and low lights started flashing, shut the truck off, they both turned off. Took it out today, tried to go into 4, both lights started flashing rapidly and will not go out no matter what I do, truck is in 2 luckily, but I need 4 to be usable. Any ideas where to start?

 

Check your limit switch voltages at the 4wd ECU as outlined in the thread below and post your results so we can see where we need to start looking.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

Ended up getting it to engage and disengage multiple times. Once or twice when I disengaged it, both lights would flash briefly and then turn off. I think it might be a connector under the truck to one of the actuators, but not sure. I’ll check the limit switch voltages here shortly

 

I'd almost bet the vent hose came off one of the actuators and the actuator is getting water in it.

 

That’s what I’m thinking. I mean the truck does have almost 270k on it. The front actuator was replaced last year, albeit with a cheap Chinese one, mainly just to test things. I actually just pulled the OEM one apart and it was basically spotless inside.

 

Yea alot of parts get thrown at these when they don't work because people don't understand the system, the testing methods we've developed have really helped to pinpoint the part of the system that is causing issues so further testing can be done on the specific part rather than replace everything and hope it works.

 

Exactly, I’m very prone to just throwing new parts at things… I’ll definitely check all voltages too, probably won’t get around to that until tomorrow. Also plan to check the vent hoses, and might pull the t-case actuator and pull it apart to clean out.

 

Just note if it is working at the time you likely won't see any abnormalities in the voltages, testing needs to be done when it's broke.
Also if you pull the Transfer Case Actuator make sure to mark the gear so timing is not lost.

 

I’ll definitely remember to mark that. Don’t want to make things even worse..

 

Update, figured it out. Went under the truck and hit the front actuator with a hammer. Both lights cleared. Did it 3 times just to check. Makes sense as I threw a cheap Chinese actuator in a few years ago. Going to solder up my old oem one and throw it back in tomorrow since it’s in good shape and super clean inside still.

 

Glad you figured it out, thanks for coming back with an update

 

I’m glad it’s a relatively simple fix. I plan to solder my old OEM one up tonight and seal it up with silicone or permatex and then put it in tomorrow and hope it works. Only reason I replaced it was I had issues with it wanted to engage or not, but I’ve had the same issue with this Chinese actuator so I think it’s just a matter of not using it often enough

 

Yea you gotta engage it regularly or things will stop working.
I just had that happen with the locker on mine, hadn't engaged it in ages and I thought I'm gona engage it once. Well what do you know blinking diff lock light and no engagement, being the diagnostic guy I am I got out the scope and started checking the limit switches and motor terminals at the 4wd ECU.
Had power and ground out to the motor but no movement on the limit switches, put an amp clamp on the motor wires...10 amps. At that point I knew the motor was stuck, got someone to hit the switch while I tapped it lightly with a hammer and off we went. Now it works perfectly again.

 

That’s basically what it would do, half the time I’d try engaging it and get nothing, so I bought a cheap Chinese actuator just to test if it was my actuator, didn’t wanna buy a brand new oem one in case it wasn’t. Well it wasn’t my actuator, but I figure it I’m going to put the oem one back in might as well fix the weak points now and waterproof it the best I can. Who knows maybe the Chinese one will be salvageable as a backup even. Definitely going to try and engage it at least once a month or more though.

 

Mine has done that from day one. What I have found out it needs to be exercised a lot! don't wait till it snows yes you can turn it off and on the road the big issue is 4 low but that can be done in the drive way or a parking lot. I plow snow with mine in low range (much easer on the truck). I f'ing hate it with a passion want the stick on the floor and lock out hubs!

 

That’s the big thing, I tell myself every year I’ll use it through the summer and then never do. Then snow hits and it doesn’t want to work at first. It’s even worse when you need it and go to use it and it doesn’t want to engage. I’ve had that happen a few times and looked like a fool…

 

I have even left it running light's flashing the whole 9 yards came back out lights out fully engaged 20 minutes latter.