Center Diff Lock Light

[Derekv]

2004 V8 4Runner.

Center Diff/transfer case is locking, but the lock light on the dash just flashes. It worked before, just recently stopped working. Is the switch internal to the actuator motor housing?

2 years go I pulled the diff/transfer case and replaced actuator seals. No more leaks and everything worked perfectly until this winter.

Derek V

 

[MikeinNH67]

This is one of those items that works best when exercised occasionally. It also locks in easier if you let the truck creep forward or backward while it's trying to engage.

 

[Derekv]

I do exercise it regularly and the actuator works. But the lock light never stops flashing. Eventually it unlocks and stops. So the sensor that tells the system it is locked isn’t working. Where is the sensor/switch?

Derek V

 

[aemravan]

I do exercise it regularly and the actuator works. But the lock light never stops flashing. Eventually it unlocks and stops. So the sensor that tells the system it is locked isn’t working. Where is the sensor/switch?

Derek V

So just to be clear, you have confirmed engagement of the center diff lock? How are you verifying this? To answer your question, yes, there is a feedback loop in the actuator that is supposed to tell the 4wd module which position it is in, this is done via limit switches. So theoretically, if you center diff lock switch crapped out and isn't engaging and sending back its position it could be that problem even though physically it is engaged. The fact that it is blinking means that the car thinks it has not engaged, and is reasonable to think that after a bit of time of trying it would then return to the disengaged position.

 

[Derekv]

Correct, it is engaging. I can hear it engage and turns at low speed, I can feel that it is engaged.

I have got the lock light to stop blinking by getting it into 4 Low, but that rarely works.

So the limit switch that indicates it is locked must not be working. I did remove and clean the plug on the actuator housing.

Any pics of that switch? I understand if I remove the cover, gear will come with it.

Derek V

 

[Derekv]

Any advise on opening the actuator module up and checking the limit switches?

Derek V

 

[aemravan]

unfortunately I doubt anyone will be able to shine much light on opening (and successfully closing) the actuator with repairs. I would wager that only a handful of people even attempted this.. most just swap the Tcase or go the FJ cruiser route.

I THINK the proper way to do it is to drop the Tcase but I could be completely mistaking.. I would imagine you also have to be very careful about taking it off as it is position sensitive and you could end up with a fixed position switch but a messed up over actuator due to mistimed positioning . Sounds like your actuator isn't happy overall since you can't get it to go to 4Lo all the time.

If it actually is locking and the only issue is the limit switch not telling the ecu it is locked it could be worth digging through the wiring diagrams to see which wire is responsible for that signal and putting a switch to it so you can feed that signal in yourself.. not idea.. i know, but could be a quick and dirty way to go about patching the issue for a while..

 

[4RunnerAquasport]

Really don't know anything about it. Swapped mine to a manual shift just recently, before it became an issue.

Did a quick search:
First 2 links have repair pics, 3rd link is several pages of people that have dealt it, hopefully there is something in there that will help.
Good Luck!

DIY: Transfer Case Actuator Repair

4lo Actuator Rebuild

Actuator Google search

 

[BlackWorksInc]

Correct, it is engaging. I can hear it engage and turns at low speed, I can feel that it is engaged.

I have got the lock light to stop blinking by getting it into 4 Low, but that rarely works.

So the limit switch that indicates it is locked must not be working. I did remove and clean the plug on the actuator housing.

Any pics of that switch? I understand if I remove the cover, gear will come with it.

Derek V

Have you tried rocking the vehicle back and forth in drive and reverse? They can get sticky sometimes and you have to "jiggle" the system.