Headlight system and pre collision system warning

My son borrowed my 2019 Tacoma for a few weeks and I get it back to find warning lights saying there is an issue with the headlight system and PCS. Got a fuse tester to test all fuses and the 3 right next to each other will not light up the tester. 4wd , ECU IG No 1 and ECU IG No 2. Truck runs fine other than can’t use cruise control because of these warnings. I even changed the fuses and still nothing.

he says it started when he went through the car wash before bringing it home.

Any thoughts?

 

Before even reading the last part I knew it was something with water intrusion.

what was he doing before the car wash? the car wash alone shouldn’t have fried anything, plenty of folks on here hit the car wash frequently without problems. The only way that could possibly lead to your issues is if the fusebox was submerged or the cover was off. Any shot he took it mudding or did some sort of water crossing (intentional or accidental) but didn’t tell you?

If it’s running fine and you don’t have any obvious misfires then it’s definitely something electrical

 

Based on the amount of mud I cleaned out - quite possibly. Is this a dealer fix or anything I can do myself. Anything for me to try ?

Kristy

 

Depends on the actual problem of course.

IMHO son needs to be bearing the burden here. It's fair for you to expect to receive the vehicle back the same condition you loaned it in. And I'd guess it wasn't full of mud when he picked it up.

Speaking of which, exactly where was this mud? Floorboards, as in foot traffic? Or elsewhere?

Have you examined the area behind the grill? Are the condenser fins filled with mud?

 

Oh boy. Again, you can definitely take a taco through some mud and water, but depth and duration are important factors. If I had to guess it sat in something wet for longer than it should have and the push connections on the PCS, headlights, and maybe something else got soggy and then corroded. Also if he got water up that high then the wire bundle itself could have some other failure points. Woof.

A dealer is going to tell you to replace everything when hopefully there’s a much cheaper solution. I would go to an independent shop first that’s reputable and knows Toyotas.

 

I don’t think he left it sitting in water or mud. I have an AirTag in it and it was never left anywhere for a long time.

I took it to the car wash after I got it back. Mud was mainly up in the fender wells and tires.

I saw the truck nearly every day when he had it. He used it for work and was on “B” level roads which are basically mud.

Guess we will see what the shop tells me.

 

If your son will tell you where and how it happened it might be easier to diagnose the problem and make the repair more reasonable.

 

Make sure the grille garnish in front of the millwave radar is clean. Make sure the windshield is clean in the PCS camera area (it's to the right of the rear view mirror). The automatic headlights use photo sensors on the dashboard to detect light, so make sure they aren't covered. Did you pop off the dash speaker grilles at any time in the past (say, for running dash cam wiring down the A-pillar)? If so, check the photo sensor wire connector is secure.

Other than that, you'll want to scan the PCS system and body control module (BCM) for codes rather than shooting blind.

 

The shop called , code C1AA0. Said front camera needs replaced. $2300.

I will see what I can find about doing this myself. Until then I will just not have cruise control and alerts popping up.

 

^5 minutes Googling seems to confirm: https://www.reddit.com/r/Toyota/comments/17bwp6h/front_camera_replacement/
https://www.autocodes.com/c1aa0_toyota.html

You can buy a used camera for ~$100 from eBay, swap it yourself, and take your chances without re-calibration.