If you’re heating/cooling/fan system and heated seats have stopped working because of fuse#10 READ!!

My Blindspot monitoring system stopped working about three years ago. I was quoted $6000 to fix it and said fuck that! Last year my heated seats, defrosting/fan/heat system all stopped working along with the TEMP gauge which read E. it’s of course happened both years in the middle of winter and I live in Canada!

I took it to Toyota and explained I had already tried replacing fuse number 10 a few times, and it would work for a short period and then blow again. They replaced it and ran it for a while and it didn’t blow. I think this is because it’s out inside their warmed garage for over four hours while I waited and I do not have a covered area at home so I think it dried out. A few days later it blew again, and I was told I would have to pay a lot for diagnosing and fixing it so I said fuck that again!
With the help of some awesome people on this forum, I was able to narrow it down to the BSM sensors in the rear bumper. They are on the same circuit as the other system.(IG1 No.2) I removed the bumper and could immediately see on the right hand side there was corrosion all around the screws and metal holding the sensor on. There was also corrosion in the 10 pin harness, and wires that were exposed and wet looking. I dried everything off applied dielectric grease and wrapped it up really well. The left side seemed fine but I wrapped the wires. That lasted for a year and here I am again with the same issue.

This time I removed the sensors and found an absolute ridiculous amount of corrosion and salts inside! On both sides. I have disconnected both harnesses, dried them and heat shrinked them closed. There is apparently a TCB/recall in the United States for this? But not here in Canada. I am already in contact with Toyota Canada to fight about this, but I’m hoping this will save someone else a ton of stress, money, and time if you have the same symptoms!
*FYI I have a stock bumper and have never had any accidents resulting in damage to either side*

 

Wow! That’s ridiculous! Toyota dropped the ball on that….. hope you are able to get satisfaction from them.
And will add, it tickles me a fellow female did what you did in diagnosing the problem… thank you.. ☺️

 

That's insane corrosion. The biggest headache with every one of the four Toyota trucks I've owned is corrosion. These trucks belong in a desert.

 

Yes, those BSM modules are toast. Of course, you already realize that. What concerns me is that the CAN bus is present in the BSM module connectors and if your drying and sealing of the connectors are susceptible to more shorting the CAN bus may short out and then the whole vehicle may shut down.
Perhaps @caribe makaira could come on and let you know about any other connectors that could be disconnected inside the vehicle to remove power and CAN bus from exposure under the vehicle. That would/might take care of the problems until you possibly get some resolution from Toyota. Perhaps the BE2 connector, once again I have no idea where that connector is located, but it is only a 4-position connector and two are the CAN bus, plus one ground, no idea if the fourth position is even used.

 

Holy shit. Good catch!

 

thanks for sharing. hard to believe how something like this is so poorly designed and built.

 

Nice job!! Good investigative work. Thanks for sharing.

 

Mounting a circuit board with that many critical connections so low on the vehicle and behind the rear tire just seems like a ridiculous design decision.

Im sure that box could have been mounted up behind the tail lights, for example, for much better protection from the weather.

I’ll be heading out to my truck later this morning to check mine and cosmoline the heck out of that area.

 

I was gonna ask have you ever had your taco undercoated. Would it have protected this electronic box from corrosion from road salt etc. I will check mine out as I have been doing the Krown treatment on it for the 2 second year.

 

Timely.

My BSM hasn't been working the last few weeks. I took it to the car wash yesterday assuming dirt was the problem but it still isn't working. Looks like I'll be looking into this today as well.

 

Post pics if it’s toast

 

Is this fix still working for you? Having the same issue and will likely do this fix.