Pre collision system malfunction reoccuring issue - 2020 TRD sport

Long story short - I smashed up my side bed panel on my 2020 TRD sport and had to also replace the passenger side tail light. I replaced both stock tail lights with AlphaRex Pro Series LED because they looked good. Sold the drivers side on eBay for like $80. I installed the tail lights with the body damage, and there was certainly a gap between the panel, so water/moisture was getting in.

Fast forward a bit, I'm receiving Pre collision system malfunction errors left and right. The accelerator doesn't work all the time (very dangerous when pulling into traffic, the ECU thinks the brake is being pressed at the same time, pedal goes to the ground w/o movement, then red lines after a few seconds). Took it to the dealer. They replaced a millimeter wave sensor under warranty (threw bad codes).

2 days later, same issue. Take it back, they find serious corrosion on the brake light plug. They apply some dielectric grease and clean up the connections good. The brake light was shorting, making the ECU think the brake as being pressed, so I couldn't press the gas. Can't use cruise control either.

Seemed to fix the problem. Mechanic suggested if this reoccurs, I replace with OEM Toyota tail lights. In the mean time, I get the bed panel fixed, you can't even tell it was damaged.

About a month later, yesterday, the same shit is happening again - Pre collision system malfunction errors. It was also raining like crazy. Very frustrating. I inspect the tail light, looks pretty good - no corrosion. Connection looks a little gritty, but not cotton candy blue like before. Certainly not wet. The seal between bed panel and light is solid. The other tail light is perfect.

I'm going to bring it back next week, but I'm really not confident replacing the aftermarket tail lights with OEM ones will fix the problem. I can't find anyone having issues with the AlphaRex lights allowing moisture in. I think the wire harness is probably fried.

Does anyone have any experience with this? I find it absolutely insane that a shorted brake light is causing my truck to be borderline inoperable. "Safety features"

 

Geez dude, put OEM lights in it. THEN if there is a problem, Toyota will fix it. Right now it will just be a finger pointing game.

 

Get rid of the cheap knock off tails and see if your problem goes away. Morimoto XB tails are full LED and of OEM quality if you want the look and your truck to function properly.

 

I know, that's what I'm thinking, just buy a new OEM pair .. damn, shouldn't have sold the other one I had. Live and learn I guess.

 

Those Morimoto ones look nice, but I think I'm going to have to replace the pair with OEM factory ones to really figure out the problem :/

 

There are about to be A LOT of OEM tails going up for sale on here. You'll be able to get a set really cheap once MESO starts delivering those XB's

 

Yeah I see that, unfortunately I don't think I'll be able to wait and will likely have to pay $400 for a pair at a local dealer

 

Wow, this TSS sensor issue is interesting. Could it be caused by the non-sealed tail light? (I'm guessing it is)

So far, no issues on my 2021 Sport.

 

Same exact problem, and both - lights and the gas pedal issue ... Once it starts, it doesn't go away. But its intermittent - it may only happen 4-5x on a 45 minute drive ... almost always involving low speed, starting from a green light or top sign. Never on the highway or at high speeds. Really bizarre. The mechanic said these features came about after the Prius issues years ago. Like a fail safe.

 

Yeah I'm 100% certain it was related to me driving around with an exposed/non-sealed tail light for a few weeks before I got the body damage fixed ... I'm afraid the exposure screwed up the integrity of the wiring.

 

I feel like an idiot ... I removed the drivers side tail light, the side that has no damage, and the thing is corroded and wet af ... lesson: don't buy cheap after market shit products

 

I'm just surprised the dealer didn't think to check the other one ... oh well, I feel better about it now ... $750 later for tail lights, when I could've just bought a single one for $200 :/

 

What’s your location

 

I'm in new england but I pretty much need them asap as I have a road trip planned for mid next week

 

You can band-aid that in the mean time until you find some reasonable priced replacements.

-Clean out all that built up crap.
-Sand/scuff the contacts.
-Plug the bulb back in, and coat the bulb socket junction in liquid electrical tape.
-Put it back in the housing, and now coat the seam of the housing and socket in liquid electrical tape.
-Do the same where all the other sockets attach to the housing.

You'll be water tight for a while.

 

This is the move. Bandaid until you can get some used OEM on the cheap