Most liked posts in thread: F/S: JCW Sparco seats

T3hSaladin for me

 

You paid like $500 for that OC3 mat right? :lol:

 

Apparently not. Orangecrush just got JCW seats for his R56 and has an ongoing thread on NAM about installing them. The weight sensor has a microcontroller circuit that talks to the computer on the data bus. This can be seen in the wiring diagrams. To bypass it would require someone like Ian Cull (developer of windows up circuit) to analyze the messages and come up with a circuit to mimic it. Some people have even reported that if you change the sensor mat (new or from a different car), the dealer needs to program it into the computer. The sensors may have unique ID's and the computer has to be told to recognize it.

 

DAMMIT!

I was going to buy another sensor, if I could find one. I have no desire to rip the one out of my english panther leather passenger seat. I wish there was an easier workaround. Wonder how hard it would be to remove the light itself.

 

If you measure the Ohm rating of the sensor you should be able to just get a resistor that would work for it. We've done this with the airbags... this isn't any different. It maybe even easier and just need a closed circuit.

 

I have found this to not be the case. If you look at the install guide that I wrote up, there is a picture of the seat mat in question.

I have used resistors for both airbag seats as well as the two airbag circuits that are in the steering wheel.

 

I don't see how just a resistor could work. The connection to the mat assembly is a data bus.

You need the microcontroller circuit to talk to the computer and it comes with the mat. Maybe a resistor could work if you want to ditch the mat itself, but you would be putting it on the circuit board and you still have to start with the full mat assembly.

 

Again, they wouldnt be the same as the air bags. But the point is it's a switch. When it is "on" (someone sitting on it) It either sends a signal or closes the circuit.... etc. A simple multimeter with ac/dc/ohm/continuity should be able to give you the information needed to figure this out.

 

But isn't it a "Smart Switch" that knows when the weight is less than X for off. Also can determine the force to deploy depending on weight when on.

 

Right, so my point is at some point its "ON" So make it so it's on. Are you people with JCW and other race seats really putting a baby seat in the front?

 

That's what I'd like--just leave it on all the time. There's no reason for it to be disabled in my car; there will never be anyone other than an adult in there anyway.

 

When I had the seat mat out of my car, I did put a meter on it and the data was not helpful. I can't remember now exactly what the reading was, I think it just showed zero resistance. Again, I have fooled the airbag system on both seats as well as the steering wheel (I have a sparco wheel), and the seat mat is different.

 

The mat is connected to the car through a DIGITAL data bus. You can't fool it with a resistor! This is different from the airbags. There are two components to the mat assembly: the actual sensor mat itself, and its electronics on a circuit board. The sensor mat portion is maybe replaceable with a resistor but the electronics portion is needed for communicating on the data bus. You can't get away without an OEM mat entirely -- you will need at least its digital controller.

This is a pic by orangecrush from his seat swap with the circuit board visible.

 

Yikes! They do make it complicated, don't they?

So that's why my car starts gonging at me when I have a 12lb Mini-pooper in the front seat.....

 

Well what exactly does the board do. It's going to change a signal right? Then the bag turns on or off based on what? The pressure on the seat being X weight makes it flip a switch? What's it doing BEFORE the bus? etc etc etc

It's really not that complicated. Maybe it is, but it just takes time. I mean, you only have to be smarter than the mat! Frankly I'd do it my self if I had one. But I dont need to as I have an 04...a... and 2 it doesn't have an airbag there anymore due to harnesses.

Maybe instead of saying how it can't be done. Someone could be helpful and figure it out? That seems like a neat idea.

 

Yes, "all it takes" is to sniff the bus and have a microcontroller mimic the behavior. However that's a big step from the resistor and beyond the capability of most DIY enthusiasts. There is a market opportunity if someone would actually do it and offer a solution.

 

The less you know about something the simpler it seems.

 

I can't believe the defeatist attitudes in this thread. Imagine if everyone who's done anything great just sat around and waited for someone to do it. LOL We'd be living in the dark ages.

Good thing the Unpossible market still exists. I'll have to think of something good for my project that is more unpossible than ever before.