4wd and center diff light flashing, no 4lo either

Hey everyone,

First post here. I was searching for a thread but couldn't find one with my specific issue so I figured I'd post my own.

I recently got a 2003 4runnner with the 4.0. When switching to 4hi, the 4wd light and center diff lock lights flash. If I switch to 4lo the light flashes and beeps.

I've ready that it could be the front actuator but I've also read about people replacing/fixing the actuator in the rear.

I was hoping to maybe get an idea of things I can troubleshoot before shotgunning parts at it.

Any tips/help is appreciated.

Thanks!

 

There’s only one actuator I’m aware of and it’s likely stuck due to disuse. This is a known issue. I recommend searching “4th Gen stuck actuator” here, at t4r.org, on Google, and on YouTube. People’s remedies have included everything from disassembly (no thanks) to tapping with a hammer to just repeatedly trying to engage the 4WD every time they drive and many more things I’m sure. Be sure you’re following the procedure for engaging 4WD, which is in the manual but should also be on the back of the driver’s sunvisor.

When you get it working, drive 10 miles a month in 4WD at a minimum (per the manual) and work it through all modes as well, including engaging the locker in both 4HI and 4LO. I usually drive the 10 miles in 4HI then take the next opportunity in a parking lot or wherever to do the locker (be sure not to turn on dry pavement with it engaged), then disengage the locker, shift to 4LO (stopped and in neutral), drive a few seconds, engage the locker again, drive a bit more, stop, neutral, then back to 2WD and you’re done.

Hope you get it squared away b/c replacing the actuator is $$$$.

 

Possibly referring to the front axle disconnect as an actuator but I'm guessing.

 

@shixonjr - Here’s an example of someone who claims to have a fix. YMMV and try at your own risk of course.

 

Thanks for the input everyone. I'm gonna get under it over the weekend and take a look at the front diff actuator. As well as the one in the rear.

This is the front one for reference: https://www.rockauto.com/en/moreinfo.php?pk=8876608&cc=1418239&pt=10456&jsn=10354

I've read that these go out fairly often. Seems easy enough. Will update when I figure it out.

 

Well, "easy enough" isn't something I've ever seen in an inoperative actuator thread, but hey, I'm open-minded and hope it's exactly that!

What are you referring to as the rear actuator? As I understand it, the one on the diff is the only thing aside from the 4WD module behind the glove box (and obviously the dash knob) that affects 4WD engagement/disengagement.

Hmmm...@xtremewlr, will the lights come on and/or flash if the dash knob is unplugged in the back?

 

I did a little more research and that front actuator is part of switching to 4wd, etc. Tends to get gunked up and go bad. It's only connected with 4 bolts. I'll have to drain the front diff and refill it but it doesn't seem that hard.

 

Were you moving when you switched to 4 high? Sometimes it won't engage if you aren't moving. Only when switching from 4 high --> 4 low do you need to be stopped.

 

I tried while moving, in neutral, in park, in neutral moving a little. Doesn't switch. I did read that when the weather heats up it switches easier, but it's been in the 30s here all week so that's not happening lol.

 

I honestly don't recall. I haven't had a shift knob on the dash in mine for about 2 years or so now.