Jason
Member
Ok, my car has been going into limp mode and then shortly after I get a P0102 code, being the only code I receive. I'm assuming it's my MAF (I have a Saleen Velocity MAF). Before I spend the time to find it first of all, then dish out the $200 or so, I want to check everything out first as to not waist my money and the MAF not even being my problem.
First im checking to see if I have any breaks in the wires. I checked the continuity from the MAF signal and MAF signal return coming from the PCM, those are fine. Ground is also fine. The problem I am having is with the 12v power wire. I probed the wire at the MAF with the key on, engine off, and I was receiving no power from that wire. So one of two things, I'm doing something wrong, or I have a break in that wire. I went ahead and looked at the wire diagrams with no luck with continuity, but I want to double check something first
I looked at this diagram http://iihs.net/fsm/?dir=40&viewfile=Electronic%20Engine%20Controls%20-%204.6L.pdf
According to this diagram the power wire belongs to circuit 391 which also belongs to the same circuit that the VCT's and EVAP (among other things) are getting power from. Those components are all getting the 12v with power on, I even verified that they belonged to the same circuit by checking the continuity from their power wires. All those wires have a RD-YE color wire but my MAF power wire is VT-YE which has me confused because the diagram says it should be RD-YE.
However, I found the picture below which says that the MAF on manual transmissions has a VT-YE color and belongs to circuit 1139. This wire diagram does not have a diagram for a manual transmission.
All this brings me to some simple questions, does anyone know where my MAF is getting it's power from so I can check for continuity between the wires? Or does anyone have the diagrams for the Manual transmission that has the VT-YE wire and the 1139 circuit? Am I correct in probing the power wire with just the key on, engine off, or do I need to do something different in order to see the 12v power?
First im checking to see if I have any breaks in the wires. I checked the continuity from the MAF signal and MAF signal return coming from the PCM, those are fine. Ground is also fine. The problem I am having is with the 12v power wire. I probed the wire at the MAF with the key on, engine off, and I was receiving no power from that wire. So one of two things, I'm doing something wrong, or I have a break in that wire. I went ahead and looked at the wire diagrams with no luck with continuity, but I want to double check something first
I looked at this diagram http://iihs.net/fsm/?dir=40&viewfile=Electronic%20Engine%20Controls%20-%204.6L.pdf
According to this diagram the power wire belongs to circuit 391 which also belongs to the same circuit that the VCT's and EVAP (among other things) are getting power from. Those components are all getting the 12v with power on, I even verified that they belonged to the same circuit by checking the continuity from their power wires. All those wires have a RD-YE color wire but my MAF power wire is VT-YE which has me confused because the diagram says it should be RD-YE.
However, I found the picture below which says that the MAF on manual transmissions has a VT-YE color and belongs to circuit 1139. This wire diagram does not have a diagram for a manual transmission.
All this brings me to some simple questions, does anyone know where my MAF is getting it's power from so I can check for continuity between the wires? Or does anyone have the diagrams for the Manual transmission that has the VT-YE wire and the 1139 circuit? Am I correct in probing the power wire with just the key on, engine off, or do I need to do something different in order to see the 12v power?
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