Intermittent 4 wheel drive light blinking

I have a 2001 4wd Tundra Access Cab. Recently the 4wd will not engage and the light continues to blink. This happens intermittently. Maybe 1/3 of the time the 4wd will engage as it should. Since this is an intermittent issue, any recommendations on where to start looking into the issue? Thanks

 

Most likely one of the 4wd drive actuators that needs to be opened up and cleaned of corrosion.

 

There's probably more information here than you need, but midway through you'll see how to dismantle and clean your actuator.

 

Thanks for the replies. It looks pretty simple to open up the transfer case actuator and clean it. I think I will start there.

 

I tried to remove the 3 bolts to clean my actuator today. I broke one of them off and never did get the thing apart. The thing is pretty rusty overall. I'm thinking of just replacing the whole thing with a new OEM unit. It looks like they are just under $400. Thoughts?

 

Yeah, that happens. Between the cover and the service plate I had to drill-out/re-tap 3 of the 6 bolts when I repaired mine. I would have bought a new one, but I'm in that phase where I have more time than money. (I won't derail this thread, but I think I'm much happier than when I had more money than time...)

 

Hey w666, did you get it fixed?

 

Yeah...scroll up and watch the video, it shows how to open and clean your actuator. For the drilling and tapping, however, you're on your own.

 

I know this is old and has been well covered but this was the most helpful video from w666 so thank you for the info!
I had both 4hi and 4lo lights flashing at all times with no other noises or problems related. I couldn't hear the actuator working when pushing any buttons either.
I went straight to cleaning removing and cleaning the transfer case actuator and it was more corroded than the video. I was able to clean the metal contact strips with sand paper and steel wool and then apply dielectric grease on everything. And this fixed both flashing lights!

 

FWIW there's a small hose attached to the actuator that looks like a vacuum line, but it's not...rather it's a vent hose. If it's loose or craked or missing altogether that's the pathway by which all that schmutz gets inside.

 

Make sure the vent tube is intact and not cracked to shit. That thing cracking/falling off is the #1 cause of crap getting inside to corrode stuff. That, and people who can't RTFM to understand they need to engage 4WD every so often (Toyota reco's 10mi/month, IIRC).