2010 Sequoia Platinum

Hi Guys and Gals
I'm new to your community and I have never joined any communities before so this is a first for me. I have been reading your forums and have found you to be full of important info and facts.
I'm helping out a friend with his 2010 Sequoia. The four wheel symbol flashes. No 4x4 is the problem. I pulled the wiring harness at the centre differential and there is no 12 volt signal to be found on either of the 3 wiring connectors. The fuse is good. I don't want to pull the dash apart to get to the 4 wheel drive switch wires if I don't have to. Any suggestions?

 

I’d suggest starting by tracking down a wiring diagram. Is this a rust belt vehicle?

 

Welcome to TW!

 

Typically its the front differential actuator. I've changed lots on all Toyotas including Sequoia.

If its 4x4 the front prop shaft spins and is locked to the transfer case, but you have no front drive, its the A.D.D.

If its in 4x4 and the front prop shaft doesn't spin and you can turn the shaft by hand, its Tcase related.

 

This vehicle is on South Coast of British Columbia. No rust. I had the front actuator off and its like new. The breather hose is attached and like new. I'm not getting a 12volt signal at the transfer case connectors.
I've downloaded the wiring diagrams. I'm at the point that I have to expose the 4x4 ECU. Working in the rain and wind so not looking forward to this part of the job at all. I will let you know how it goes. Lucky for me there is no pressure to get this fixed. Thanks for the suggestions and help.

 

So if I understand correctly, when you run a 12V jumper to the t-case the actuator works normally, correct? I think you're on the right track, next steps are to verify voltages further upstream. Usually connections go bad where the wire enters the terminal (as you probably know). Bad grounds can also cause all sorts of issues. Hopefully it's not the ECM, good luck!

 

Matt: I have power at the electrical connectors at the T/Case. I pulled the lower actuator. It looks brand-new inside. I powered up the motor while I had it apart and it worked fine. I didn't pay attention to where the gear was before I powered up the motor and now I'm sure that it isn't in the right position so I am hesitant to put it back in place. Can anyone help with a picture of the positioning of the gear related to 2 wheel drive which is what the vehicle is in now.

 

I think this is what you're looking for. https://www.tundras.com/threads/2007-2020-transfer-case-actuator.61182/

 

Thanks, I get back at it tomorrow. I'll let you know how I make out.

 

Welcome to the best forum.

 

Good luck, these electrical troubleshoots can be a real pain, especially when it's not one of the common culprits. But if you're methodical, follow the wiring diagram, and work backwards you'll get it sorted out. I tend to check grounds first since they're often more exposed to the elements.

Let us know what you find.

 

Matt, Bishop and all the rest of you guys, thanks for the suggestions and help. Problem solved. It seems like the last time this vehicle was put into 4x4 the front diff actuator motor must have been stuck as it didn't shift the fork over to engage the front diff. The 4x4 shift actuator at the transfer case did in fact make the shift but because the front drive shaft didn't turn the 4x4 shift at the transfer case didn't quite complete. I had the actuator off at the transfer case and turned the front drive shaft by hand and that completed the full 4x4 shift at the transfer case. I timed that actuator to 4x4 and then timed the front actuator to 4x4 and put it all together. Success!!! While I had the front actuator on the bench I squirted "power lube" down along the motor shaft at the worm gear and then activated that motor back and forth to help free it up. It works for now but I can see future problems and will suggest to my friend to purchase a new actuator for the front diff. The breather hoses were in good shape at both actuators and at first glance everything looked like new. Then I did notice a bit or rust on the worm gear in that front actuator and the motor did sound like it was labouring hence the "lube".
Thanks again for all your help!!

 

Glad you got it sorted out. It sure seems like the problem is in the t-case most of the time!