rb25det240

B-Man, I may have the info you need. I have the q45 MAF on my car (RB25 in an s14a Silvia Chassis), but it is at home, and I am at work. I am trying to remember, and I believe that the power and ground are reversed from the rb25 MAF (series 2 anyway). I will look when I get home and see what is going on. In the meantime if you want, below is my writeup of how I determeined the correct pinout, so you could do that too if you want. I couldn't find the info anywhere on the net either and ended up using a voltmeter/ohm-meter to deduce how to hook it up. First, figure out which wire is which from the ECU (I.E. Ground one lead of the ohm-meter on the body of the car/head/block, and touch other lead to the wires from the ECU, the one with Zero ohms is the earth, next switch the ignition on and test for which wire has 5-volts, that is power, the left over one is the signal). The next part is harder, compare the resistance between the pins on the rb25 MAF to the resistance between the pins of the q45 MAF. I don't remember exactly what the values are, but they roughly similar (I.E. same amount of resistance between the power and earth pins on both MAFS etc). You know what the pins on the rb25 are from the first step. Measure the resistance between the earth pin and signal pin on the 25 AFM, then look for the same reading between two pins on the q45 AFM. When you find the same reading, you know that those are the ground and earth pins, but you don't know which is which. However, you do know now which is the power pin on the q45 (the one that isn't ground or signal), MARK IT! Now, measure the resistance between the power and signal pins on the rb25 MAF, look for that same resistance between the power pin and one of the two unidentified pins on the q45 MAF. When you have found that, you have found the signal wire. Mark it too. The remaining one is the earth pin. There you go! Like I said, I think it ends up that the power and earth pins are simply reversed from the rb25, but I don't remember for sure. Greg Mitchell P.S. If you can't find similar resistances between pins on the known working MAF and the Q45 MAF, there is a good chance your VH45 MAF is no longer working. Also sorry about the Americanisms in the post, but that is what I am, and I don't have the time to change them all to Aussie friendly terms, but I did try a little, (earth instead of ground) Oh yeah, and typos, I am sure there are some of them mixed in as well. Looks like I also used VH45 and Q45 interchangably, the American version of the President is called called the Q45, so that is where that came from.