Okay guys, I've been scratching my head on this one and I'm out of ideas, so I figured if I could find the answer it would probably be here.
Background: 1997 4runner Limited with the pushbutton 4wd. Tried to engage 4wd the other day and nothing happens. No lights come on in the dash, no flashing lights, nothing.
What I have done so far:
Crawled under the truck to see if the transfer case motor is driving when the 4wd button is pushed; it is not. I applied 12v to the transfer case actuator to verify the motor would manually drive, and it did, so I know the motor is good.
I verified the 4wd switch on the shifter knob is working (continuity check).
What I can't seem to find is an overview of the 4wd system's operation. Does the ADD system up front have to engage 1st, and then the ECU lets the transfer case engage? Or does the transfer case actuator do its thing, then allowing the ADD system to engage? In other words, could the ADD system prevent the transfer case actuator from getting its 12 volts?
Background: 1997 4runner Limited with the pushbutton 4wd. Tried to engage 4wd the other day and nothing happens. No lights come on in the dash, no flashing lights, nothing.
What I have done so far:
Crawled under the truck to see if the transfer case motor is driving when the 4wd button is pushed; it is not. I applied 12v to the transfer case actuator to verify the motor would manually drive, and it did, so I know the motor is good.
I verified the 4wd switch on the shifter knob is working (continuity check).
What I can't seem to find is an overview of the 4wd system's operation. Does the ADD system up front have to engage 1st, and then the ECU lets the transfer case engage? Or does the transfer case actuator do its thing, then allowing the ADD system to engage? In other words, could the ADD system prevent the transfer case actuator from getting its 12 volts?
