I've searched all over the internet and can't come up with a straight answer. Some multimeters are capable of reading DC frequency, but I don't know if mine is or not. If I rotate the dial to Volts AC and press the second function button, it will read in Kilohertz, but I don't know if I'm seeing DC Kilohertz or AC Kilohertz. The MAF sensor sends a DC square wave to the computer. I'm getting a reading of 2.9 Kilohertz when I back probe the signal wire, but I can't see how that's possible if in fact the meter is set to AC frequency. The service manual says I'm supposed to have a minimum of 1.2 Kilohertz going to the computer. Anything less than that, the computer will throw a P0102 DTC. If anybody is bored enough and doesn't mind finding out if my meter is capable of ready DC frequency, I'd appreciate it. The meter I have is a Fluke 77-IV. Thanks fellas.