4HI & 4LO Still Blinking after Actuators Replaced

Hi All - I know the 4HI & LO blinking has been addressed in lots of threads, and I was able to fix my 4WD issues by replacing first the transfer case actuator and then the ADD actuator (the ADD was the actual problem)

Now I can go into and out of 4HI & 4LO normally and reliably, but when I start the car in 2WD, the 4HI & 4LO lights are always blinking. If I stay in 2WD and push the 4WD switch 'in' without turning it, the lights clear. And if I switch to 4HI, the lights clear and stay off if I switch back to 2WD or to 4LO.

Sometimes, when I switch from 4HI back to 2WD, I have to push the switch 'in' to get it to transfer.

Thoughts? Does this point to a faulty 4WD switch or something with the 4WD ECU? I did a battery reset, no change. Would a zero point calibration help because it seems the VSC system is connected the the 4wd system. Thanks for any help

 

Sounds like time to look at wire diagrams, unplug the switch and use jumpers to see if you have a bad switch.

 

https://www.tundras.com/threads/ultimate-tundra-wiring-diagrams-collection.81448/

 

Thanks, I was pouring over the diagrams when I replaced the actuators. A little confused by this switch though: The 4WD control switch has 5 pins. Jumping 4-5 seems to be 2WD operation and 4->2 seems 4LO but then I don't see how the 4HI is triggered. Thanks for the help

 

Those black triangle symbols indicate that there are two diodes built into the switch. 4,5,2, delivers 4H

 

Thanks for the quick replies. I pulled the switch and no continuity in 2WD btw 4&5, but continuity when pushed. So then plugged it back in and started the car with the switch pushed and no flashing error lights. Sheesh don't know why it took so long to check this... New switch is on the way - thanks!

 

No problem! Welcome to the forum from OKC!

 

Wow thanks that's a great chart to reference, I'll keep that for the future. I just got the new switch and it cleared the flashing lights. Easy fix on this one

 

thats a nice chart for some general diag work A+