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Hello YA,
I have the aforementioned car. Convertible. It's the V6. I'm getting a P0102 Mass air flow code. It pops up RIGHT after a OBD clear. The car runs very well.
I Cleaned the MAF sensor and put in a new filter. The fuel trims are dead on 0. Very nice. However, I can't get the code to go away.

So, I did a multimeter check on the connector to the MAF sensor. Has 7 wires. Middle wire is RED number 4. I've read that PIN 4 should be 12 volts. YET, it reads ground.
I'm suspecting a short to ground somewhere. The connector is cracked and I've put some water proof tape on it. If I jiggle it, the engine does change idle.
YET, jiggling a bit does not change the ground zero volts on PIN 4, RED wire. I know I need to replace the jack, yet I feel there is something else going on.

My question is what would cause PIN 4 to stay ground. A short in a relay? I've tried to find a relay or some info on where this red wire goes but not much out there.
I've have read something about a possible relay above the rear axel. Odd. Does anyone have an idea of this low volt and or grounding.

The car leaks water, OF COURSE, so maybe some relay got wet and shorted. AND, why does the car run so well?
Unplugging the MAF jack stalls car. It seem the sensor is working but HOW when number 4 wire is not 12v more like zero or ground?

Steven
 

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How did you go from 12v to measuring ground? They are 2 independent things. If you are looking for 12v and see 0, you don't see a ground, you see no voltage. If you check resistance after reading 0v, then you can see if you have a ground. But yes, there should be 12v there if I read the diagram right.

Edit: These sensors are not designed to be cleaned.

Also, check out the FSM, and look around page 90-56. That has the wiring for that.
 

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Discussion Starter #4
What are you measuring your voltage against? What are you using as ground?
Hi Ya! I'm measuring ground at chassis ground. i.e positive meter on PIN 4 and negative meter on clipped on bracket of generator. Am I messing this up? Should negative meter be somewhere else. I turn key to ON but not started and I get 0v. Turn off, an do continuity at same leads and I get beeps on meter. Low res maybe?
 

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How did you go from 12v to measuring ground? They are 2 independent things. If you are looking for 12v and see 0, you don't see a ground, you see no voltage. If you check resistance after reading 0v, then you can see if you have a ground. But yes, there should be 12v there if I read the diagram right.

Edit: These sensors are not designed to be cleaned.

Also, check out the FSM, and look around page 90-56. That has the wiring for that.
HI. well, sure, ZERO is not ground. Maybe I'm jumping the gun by calling it so. I get very low CLOSE to ground continuity with a beeping meter between pin 4 and clipped ground to generator chassis. I'm SURE the connector is bad! Going to wire in a new one soon. But, still..... the no 12v and even jiggle jiggle jiggle giving me nada is perplexing.
 

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Hi Ya! I'm measuring ground at chassis ground. i.e positive meter on PIN 4 and negative meter on clipped on bracket of generator. Am I messing this up? Should negative meter be somewhere else. I turn key to ON but not started and I get 0v. Turn off, an do continuity at same leads and I get beeps on meter. Low res maybe?
Nah that sounds right. Without looking at the wiring diagrams, I'd say if you're supposed to see 12V at a pin, I'd trace it back until you see 12V. Then you know where your break is. Just verify you're reading the diagram correctly. Sometimes the pinouts can be easy to flip around and get confused.

What did you clean the MAF sensor with? Did it say it was compatible with mitsubishi or karman vortex sensors?
 

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Discussion Starter #7
Yeah, the cleaning is qualified for Mitsubishi. There is a lot of crap out there that will damage. I did my research carefully.

As for the wiring, the FSM states to check the relay. YET, it does not say where it is. Well, lets say the relay in the FSM do not conform to the actual relays I find. The fuse box in the engine compartment does not list this relay. Looked all over. ALSO, the int fusebox is located on the drivers side dash in a pull out panel. Open the driver door and it's there on the side. It does not list the relay either. The relay is listed at the MFI relay. YET, I have no idea where to find it as it's not listed. I'm under the impression there are more than one.
Would PIN 4 of the MAF Conn go to a fuel relay?
I'd love to find a proper schematic that corresponds. Some just show very small break downs.
Here is my pics of panels and listings.
 

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Refer to p 13A-571 and 572 of the FSM. It's component J which is in the small, slender fuse box next to the larger fuse box under the hood. Page 13A-582 outlines the continuity check for the MFI relay.

Also, yes, the MFI relay connects to the MAF sensor at pin 4 on the MAF sensor. Refer to page 90-62 of the FSM.
 

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If you want to see if you have a ground, you want to use the ohms setting, not the continuity that provides the beep. And here is an image of the relay box to help show what you want(A-18X).

42368
 

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Discussion Starter #10
EXCELLENT GUYS! I have not fixed yet but your info led me to the missing relays. The strip of relays needed are in a cover just beside the fusebox under the hood. I don't know how I missed it. I'll take a look and should see A-18X then start testing. I'll reply when I have more info.

AN ANOTHER note! How about the ANTI theft on this car. It sucks. I think the door sensor might be sticking and intermittent, so sometimes, the alarm goes off when I unlock the drivers door. I have to close the door, lock a few times, it stops honking, then reopen. I have not dug into this issue yet, but I did pull the 2nd horn relay about a week ago and have not heard it. BUT tonight, it went off when I was trolling around looking for that relay box you guys helped me find.

Is there an easy and quick way to just disconnect this thing? Pull a relay or jump a wire? It's very loud and annoying my dog.

BEST thanks!

Steven
 
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