Hi. My engine all of a sudden started idling rough. It has less than 50k on it. I tried to test it but turns out that they fabricated the MAF sensor so that I cannot stick my multimeter probes into the back of the connector to measure while it is running. So, I did the best I could and here is what I found. There are 5 wires: Y, B/W, Pink, Black, LB. Y and B/W measure 5V. B/W and Pink measures 12V. Pink and Black measures 12V. Black and LB measured 5V. This is of course on the power side with the truck running. I take it Y and B/W is for the sensor. B and LB are for the Intake Air Temp sensor. Pink is for heating the hot wire. So, everything looked good on the power side. Then I did ohm readings on the sensor itself. Y and B/W was OL. And everything else was OL too. I probed around a lot. All OL. So, I think I need a new one?
Also, how does 12V and 5V share the same ground, B/W and Black? Wouldn't different voltages have different grounds? Or are they all some how using chassis ground as a 0V reference? But then how does 12V power flow from Pink to the negative terminal of the 12V battery?
Also, how does 12V and 5V share the same ground, B/W and Black? Wouldn't different voltages have different grounds? Or are they all some how using chassis ground as a 0V reference? But then how does 12V power flow from Pink to the negative terminal of the 12V battery?