4 wheel drive light flashing

Hey everyone!

I’ve ran into a problem this morning on my 2020 Tacoma TRD OR. I was sitting in park when I dropped something and while reaching down to grab it I accidentally hit and turned 2WD into 4H. Upon looking up realized the light was flashing so turned the knob back to 2WD. Sat there for 5 minutes when I realized the light was still flashing. Decided to put the truck in N and switch to 4H but light continued to flashed. Put the truck in D and drove a few feet forward and backwards but would not engage just continued to flash. Went on a 1-2 mile drive while the light continued to flash in 2WD. Tried to switch to 4H on the drive and would not engage. Drove to work turned the truck off and then back on during my break and as soon as truck turns on the light instantly starts to flash. Decided to disconnect the battery completely for an hour and hooked everything back on but still getting the 4x4 flashing light. I’m thinking it could be one of my actuators either on the diff or transfer case but do not know which one of steps to properly T/S this issue. Looking for guidance/advice on this matter. Thanks in advance! Attached a pic of my Tacoma just for kicks and giggles.

 

Sounds like an actuator locked up. How oftendo you exercise the 4wd?
I run in 4wd, once a month for a few miles. And haven’t had an issue. I have 93k on my baby

 

Truck has 82k miles and honestly the last time I engaged it was the start of spring and did a few water crossings. Since then have not engaged. After reading around I’ve seen Toyota recommends engaging it once a month. Problem now is figuring out which actuator is locked up and how to T/S because one is around $200 and the other is nearing 1k-1.5k for OEM. I tried to unplug the transfer case actuator and making sure I was in 2WD and then turning the truck on to see if I could potentially isolate and see if the issue when away. Not sure if that was a good troubleshooting step tho.

 

I might try lightly tapping on the actuator. Others may have a better idea

 

Have you done any water crossings? The transfer case actuator might be rusted and inoperative if it flooded. The common question to a common issue when that happens.

 

That was also something I was going to do when I got home. Have to remove my skid plates. Some have had some luck hopefully I have similar luck. I might try and disconnect and see if I can get the light to go away as well.

 

Did a few the beginning of Spring and haven’t engaged 4x4 since. Will try and tap it with a hammer see I can get it to do anything. If that one is bad they aren’t terribly expensive.

 

Good luck, they’re easy to take out and open up to inspect, maybe you can just clean it up.

But probably easier than removing the plates, I hate doing that!

Oh gosh, did you do a reroute? Hopefully you have enough room to work around it. I did that also and I’m not sure how much room it needs to take off.

 

So got home and took the engine skid plate off. I unplugged the T case actuator and turned the truck on and the light still flashing. Plugged it back in with truck off and then unplugged the front diff actuator and turned the truck off. The flashing 4 wheel drive light went away and I got a message of fault 4 wheel drive system. Turned truck off and plugged back diff actuator and started truck and flashing light came back on. Also noticed the actuator has a very low constant beeping. Will get wife to sit in truck and engage 4H and will gently hit it with soft blow hammer and see if I can get it to un seize. If not I’ve seen the videos of taking them apart so will do that before I order a new one. On eBay they are running $182 so not terrible. The T case one I’ve seen them as high as 1.5k so glad it’s not that one. Will update with my finding/further troubleshooting.

 

@Dm93
Can you direct this gentleman with some troubleshooting?

 

I don't understand you "accidently hit and turn" 4WD button. Suppose push outside of 4WD knob in, then turn, 4WD light goes on.

 

First thing that's quick and easy is check the vent hoses on the actuators, if one is detached that actuator probably got water in it.

An all system scan tool is the easiest way to diagnose the 4wd system on a 3rd gen because you can read the codes and see all the values/positions of everything which makes testing pretty easy.

 

so yesterday when I got home I unplugged the T case actuator and turned the truck on and light was still present. Hooked it back up and then unplugged the front diff actuator and turned the truck on and light went away. I plugged it back up and light started to flash again. Also I can hear a very low continuous beep coming from the actuator.

 

You mean you started your Tacoma? Most like front diff actuator is cause, if 4WD light go off when remove connector, light comes back on when put back connector. It probraly shorted out. Replace the front diff actuator.

 

Correct. I started my Tacoma after unplugging the the front diff actuator. The flashing 4x4 light went away. Turned the truck off and plugged that actuator back and started the truck again. The light came back on and started to flash. I didn’t get underneath and I could hear a low constant beep coming from that actuator.

 

Just change the actuator. Please