Originally Posted by joeldc13
Can you confirm that I have to make this mod on my MS2, I don't think there is a difference here between MS1 and MS2 but before making a big mistake, it's better that I ask you !
Yeah, that circuit will do. Of course, internally you'll connect it to the FP pin, rather than whatever pin would be assigned to VTEC.
As to MS1 vs. MS2, it's important to remember that the only real
difference is the software. Yeah, it's a different CPU class, and some of the nitty-gritty details vary, but when it comes to external I/O (stuff that physically connects to the car) it doesn't really matter which CPU you're running, the basic circuits are the same.
differences you're likely to run into have to do with which functions connect to which pins. IOW, certain pins on the CPU can only drive certain functions. Some of these limitations ave to do with the internal architecture of the CPU, others, so far as I can tell, are purely arbitrary. And then, to make matters worse, there are at least four different ways of describing a pin- by a position on the DB37, by a CPU pin number, by an internal pad 2.2 style, or by an internal pad 3.0 style.
So, for instance, JS0, X2, and U11 pin 38 all mean exactly the same thing. But if you're reading a piece of documentation written by someone with a Rev 2.2 board, and you have a 3.0, you may go nuts looking for "X7" or "JP1-4", when in reality, you need JS5 or JS11.
I think I'm rambling at this point. Rum, combined with the vapors produced by using antimicrobal cleaners in an unventilated area have this effect on me.