4x4 hi/lo vsc and abs light popping up and disappearing just as fast.

2007 Toyota Tundra Limited with 4x4 212k miles

been having this really intermittent issue where usually on first start up the dash lights up like a Christmas tree (no check engine) and then typically after a little driving or even just turning it on and off again it goes away. This only started occurring after multiple weeks of very wet and humid driving conditions so I'm almost positive moisture has gotten somewhere it shouldn't be. the 4x4 system works perfectly when the lights arent on and switches between 2x4 4x4 and 4x4lo with zero issues and does so how designed (I have confirmed that the front wheels are in fact engaged and getting power). I've cleaned and checked wheel speed sensors and the connectors on the transfer case so at this point I'm just confused and ready to ride it out till whatever is wet dries out again as the truck doesn't go into limp mode or anything.

Trouble shooting:
The battery is healthy via both voltage test and load tester
Disconnected battery
Cleaned connectors on wheel speed sensors all seemed in good health (IDK if there is a way to check if an individual sensor has gone bad)
cleaned the connectors that go into the transfer case all seemed in good health

Ideas?

 

I might try planting someone responsible in the driver's seat to watch the dash while you crawl around by each wheel gently wiggling the ABS wires to see if the lights flash. It's possible that one of them are stretched and the strands inside the perfectly good looking insulation are intermittent. They are quite fragile.

 

A very quick easy way sometimes is hook up an OBD scanner and see what codes it has. That can help point you in the right direction.

 

I went ahead and tried it again but I guess ABS codes don't go through where other codes go but after fiddling with it I managed to get into the ABS codes section and found this guy waiting for me. Pulled the sensor and gave it a clean with electrical cleaner and seems everything is alright with the sensor and connector visually. Unfortunately, I don't really know of an easy way to test a sensor or if this one is just starting to go bad so ill see if or when it comes back and prolly buy a new one.

 

Cut rear wheel sensor wire

Check continuity and jiggle the wire around. The jacket is likely compromised.

 

Awesome thx ill look into it, definitely looks like the computer is saying a cut wheel sensor wire. Time to find it haha

 

I had the same lights just recently - 2007 with 211k 4x4 too. My code reader wouldn't pick up the code, so I paid the dealer to diagnose and they said it was the right front wheel speed sensor had gotten moisture in and corroded both the sensor and the wiring connection - this made sense as the lights came on in very wet slushy conditions. I ordered the replacements and will install this weekend if all goes smoothly.

 

Right on, my code reader required going to the ABS section and filling out the car/trucks info to get the code, it wouldn't show up in the normal spot for check codes. My problem ended up being a failing rear harness, I tried replacing the sensor and that changed nothing so I replaced that center harness (only cost like $100 in total off rock auto) and she has been working like a charm since.