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I've been having a constant P0102 that just randomly popped up one day.
I have tried:
Replacing the sensor
Putting in a neinaur filter
Checking for obstructions
Checking for vacuum leaks
None of these had any effect, so I can only conclude it's the wiring. When performing some pinpoint tests, I connect the positive of my multimeter to battery positive, negative to pin 5 of the MAF plug. The voltage then changes to some weird display that doesn't show 0-12, but 0.411 for example.
I also would like to know the wiring loom routing for the MAF connector, so I can check it for breaks.
Also when the MAF sensor started acting up, the truck acquired a quirk where even when I turn the key off, the engine bogs down, but then keeps running, and the guages stay on.
Check the foam gasket that is supposed to seal the air filter box. a vacuum leak will produce that DTC also.
I have that K&N airbox. The sensor was fine with it until I added some oil to replace some that had drained out when I was replacing the steering rack, and had to remove the filter.
Test #3 in that write up appears to correspond to Pinpoint DC10 in the PCED which is what is failing.
When performing some pinpoint tests, I connect the positive of my multimeter to battery positive, negative to pin 5 of the MAF plug. The voltage then changes to some weird display that doesn't show 0-12, but 0.411 for example.
Wire labeled as PWRGND is open. Probably a break inside the insulation where you can't see it. Might be right at the connector, use a pin to pierce the insulation a ways back to check. Could be you need a new connector/pigtail..
Fastest fix if you don't want to dig too deep would be to simply install a jumper from ground to pin 5 of the MAF connector.
A P0102 is an ELECTRICAL CIRCUIT FAULT. A foam gasket can't cause it (unless the gasket is interrupting a wire connection, not likely).
Test #3 in that write up appears to correspond to Pinpoint DC10 in the PCED which is what is failing.
Wire labeled as PWRGND is open. Probably a break inside the insulation where you can't see it. Might be right at the connector, use a pin to pierce the insulation a ways back to check. Could be you need a new connector/pigtail..
Fastest fix if you don't want to dig too deep would be to simply install a jumper from ground to pin 5 of the MAF connector.
A P0102 is an ELECTRICAL CIRCUIT FAULT. A foam gasket can't cause it (unless the gasket is interrupting a wire connection, not likely).
Test #3 in that write up appears to correspond to Pinpoint DC10 in the PCED which is what is failing.
Wire labeled as PWRGND is open. Probably a break inside the insulation where you can't see it. Might be right at the connector, use a pin to pierce the insulation a ways back to check. Could be you need a new connector/pigtail..
Fastest fix if you don't want to dig too deep would be to simply install a jumper from ground to pin 5 of the MAF connector.
So I made an ad-hoc jumper and plugged it in to the ground wire. The engine seemed to run better. I used the ground point on the right side wall of the engine bay. However, that caused a bunch of other codes to trip. So I tried a different ground point, same thing. So I think i can safely say it's a bad ground, but using a jumper only causes other things to freak out.
The engine also runs kinda rough, whether the MAF sensor is plugged in or not.
More likely than not, you have other faults and, if fixing the ground fixed the P0102, the computer can move forward in flagging the newly discovered fault codes.
Post all of them and we can see it there is a pattern discernible.
More likely than not, you have other faults and, if fixing the ground fixed the P0102, the computer can move forward in flagging the newly discovered fault codes.
Post all of them and we can see it there is a pattern discernible.
These codes had never shown up before since I bought it. This is why I hate wiring. One bad ground, and the sky's the limit on what can happen. I had a motorcycle with a bad ground. When I pulled the clutch lever, the blinkers flashed.
This rough running and MAF error only started after I added some oil (a synthetic blend, because I didn't know what oil the previous owner had in it). So I'm thinking maybe something is gunked up, a solenoid or something, because it runs rough even with the MAF sensor unplugged. So I got fresh oil and filter to do a full change.
Where are the ground points on the wiring loom that runs from the MAF sensor?
Last edited by ZombiePotatoSalad; May 18, 2025 at 01:56 PM.
2008 5.4: Chasing P0102
