Blind Spot Monitor Sensor Question

I'd read some time ago that many trucks have different pinouts/wiring too. Electrical is my least favorite stuff on these trucks. But I'd happily pay $$$ if someone else fab'd it up. @memario1214 seems to know a thing or 2 with all of that hot tail stuff he worked on.

 

The trucks with memory seats/mirrors (1794 and Platinum) have a different pin-out for BSM than the ones that do not.

 

Do you have a diagram? My truck came with tow mirrors. But bsm is turned off. When I turn it on I get a error message even though the mirrors have a bsm indicator. I know my sensors are installed because I saw them so I'm guessing it has to do with the mirrors. Maybe the prior owner bought the wrong ones and all I have to do is swap the pins.

The mirrors also have reverse lights and running lights that don't work. The only thing that works is the turn indicator in the glass.

 

My signature has a link to the full set of wiring diagrams.
But to save you some digging...

Pin 18 is BSM power for non-memory trucks. Pin 9 is BSM power for the trucks with memory (and in non-memory trucks is the side marker/running light). The Tundra does not have reverse lights in any factory configurations, so those should be wired to a separate switch with your aftermarket tow mirrors.

I am willing to bet that swapping pins 18 and 9 would get you the BSM function. I do not know if you would get running lights or not but it's worth a try.

Pin-out diagrams for both sides (ignore the "present" column - that was my notes when investigating my truck):

 

Dude thank you for taking your time to respond with this info. I'll give it a shot in the coming week. But yeah I think you are right. My wife's car has bsm and I really like it. Want mine to work too.

 

Well, I tried it and it didn't work.

 

Interesting. Of course, given that they are aftermarket mirrors, it's hard telling what they were set up for.

And to be sure - those pin numbers are looking at the FRONT of the connector, not the back where the wires enter into it.

You can also try this, but be careful when doing it...
Use some pieces of small wire and apply voltage to pins 5 and 18 on the mirrors you have. Pin 5 will be the NEG and Pin 9 will be POS. You could try a 9V battery and it should have enough voltage to light up the BSM light if the mirror itself is fully wired correctly.

 

Yeah, there's no brand on them.

I did notice the diagram shows the front of the factory connector when I saw the colors. Which means it's reversed horizontally on the mirror connector. I couldn't get the pins out on the mirror side so I cut the wires 9 and 18 and spliced them. I didn't want to modify anything on the factory harness.

I'll try your suggestion. Worse case scenario I'll get another set of tow mirrors. I like their visibility. I also have the factory mirrors but the prior owner damaged the plug on both sides. I ordered the oem connectors to see if I can repair them to sell and partially fund some high quality replacements. But I couldn't get the pins out of the tow mirrors. Not sure if I'll be able to on the factory ones.

 

they are flipped horizontally and they are upside down (the clip on the connector is on top in the diagram, but is underneath on the mirrors).

And you do not want to splice those wires - they are connected to two different things. You need to SWITCH them. But also, yes, changing them in the mirror is the smart way to go on the aftermarket mirrors.

 

Yeah that's what I meant. I didn't spliced them together. I cut 9 and 18 on the mirror side and spliced the wires separately so they are switched.

 

Well I just received my eBay BSM sensors. Plugged them into the truck and without mounting or anything I am getting the BSM light on my passenger mirror but not the driver. Also not able to turn BSM on in the console. I’m still waiting on my mounts to arrive but am I at least moving in the right direction?