4WD computer controller malfunction? (1 Viewer)

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Oct 29, 2015
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Location
Lake Forest, CA
Hey guys, I talked about this in another thread, But I think it may be a separate issue, so I started a new thread. After a night of driving in rain for a few hours, the next day while my LC was off and parked, I noticed a clicking / buzzing noise from the passenger kick panel. I start the vehicle up and it stops buzzing. left it. A couple hours later I walk by, same thing. I have some family obligations, so I just let it buzz. Next day I go to check it out and notice the car battery is dead. I jump start it. let it run for 30 min. the buzzing is still there once the vehicle is turned off. I start to remove interior moldings, this thing tucked way up there, and for someone with big hands, it was a real PITA to get out. I unplug it, its stops. I notice then it is the 4WD computer. I did some searching and that's what led me to inspect the transfer case actuators.
I checked the transfer case actuators and there was some signs of water getting in there from the cracked breather tube, but not a whole lot. I put it all back together, plug it in. Test 4LO, center diff lock. Everything works fine. I leave it. Now I have a battery tender hooked up to the truck FYI. Its not my daily, just sits in the garage for the most part. Next day, same thing. I unplug the 4WD ECU, take it apart and open it. IT looks generally good, it's hard for me to tell if this is water damage? The replacement part is about $300. But I don't want to do that only to find out it was something else. I don't really have any signs that support water somehow getting in my interior. Can anyone shed some light on this? I also have a dreaded "check PCS" showing on dash. I already cleaned and inspected the sensor, but it won't go away. Can this be related? Note: I recently removed and installed my front King coil overs about 4 times in 1 week to find my desired ride height. Could I have damaged speed wire or something like that?

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Im going to guess you have a water leak, more than likely the junctions boxes in the kick panels, drivers side or maybe passenger or both.
Until you pull apart those junction boxes and visually look you can't rule it out.
To have two separate systems have an issue after rain is a very good indication that it's water related.
Does not take much water to cause issues, carpet does not need to be wet.
Good luck.
 
thanks @Leaky2014 . Ill dig deeper and inspect the driver side kick panels too. I have yet to get a good look in there.
 
reading through other forums maybe my PCS system is related to a damaged speed sensor wire.....
 
Well. I got home this evening, I plugged in the 4wd computer . It clicked 2 times and stopped. I decided to go for a test drive. No dash lights. No "pcs check". Everything worked fine. Idk what the issue is/ was. I bet the water dried up?
 
good news / bad news
now find the leak, fix it
then clean the electrical boxes with deoxIT
treat with dielectric grease
and you're good.
 
Update. Just came out
To the garage to check it
Out. It's clicking 😒
 

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