Maf Wiring

[Tungsten]

I have this awkwardly done MAF wiring. Its one of those angled connectors piggy backed onto another one with a ground coming off the one connected to the MAF. The ground is hooked up to the intake plenum. Is this some factory remedy?

 

 

 

The extra ground goes here...

 

 

Why?!

[Simon]

Someone added that pigtail. It's actually not a bad idea, as you risk stretching the wires every time you check/change your air filter, if you don't disconnect it. Grounding to the intake is fine.

[edicer2]

i had that same pos in my pathfinder and it was causing my truck to act up so i took it out and it runs like a champ now idk why they need that but it make mine run horrible with it on there. It would die randomly when i put the clutch in and barly start and spuder alot took it off and it runs like a champ now

[Tungsten]

So is the MAF connector actually a 3-pin with a common ground? MAF connectors usually have 4 wires.

[JamesRich]

That looks like one of those power chips that are sold on ebay. It's just a resistor in there that fools the MAF sensor to think more air is going into the motor so the computer adds more fuel. Some people claim they work, I think reprogramming the computer is the only way to properly adjust fuel mixtures.

James

[msavides]

That is the factory sub harness that Nissan released to fix the MAF ground wiring.

 

I expected a little better build quality out of it myself. I just installed one on my truck and so far (knock on wood) My CEL has not come back. I will hold my breath.

 

But It is Authentic Nissan.

 

Mark

Edited May 27, 2010 by msavides

[Cuong Nguyen]

^^^ do you have a part number for this?

[Tungsten]

i had that same pos in my pathfinder and it was causing my truck to act up so i took it out and it runs like a champ now idk why they need that but it make mine run horrible with it on there. It would die randomly when i put the clutch in and barly start and spuder alot took it off and it runs like a champ now

 

 

That is the factory sub harness that Nissan released to fix the MAF ground wiring.

 

I expected a little better build quality out of it myself. I just installed one on my truck and so far (knock on wood) My CEL has not come back. I will hold my breath.

 

But It is Authentic Nissan.

 

Mark

 

 

What?!

 

 

 

I just removed the sub harness and connected the real connector and now I'm getting better results but will do some more driving today to see what changed. What is wrong with the MAF ground on the stock connector?

Edited May 27, 2010 by Tungsten

[adamzan]

^^^ do you have a part number for this?

X2 I want one. I also find that when the maf wiring is "acting up" that the truck will hesitate accelerating in 1st causing the tranny to slam into second. When it starts doing that its not long after that it starts to stall out when braking around corners. Wiggling the wiring makes everything go back to normal again.

Edited May 27, 2010 by adamzan

[GrimGreg]

What?!

 

 

 

I just removed the sub harness and connected the real connector and now I'm getting better results but will do some more driving today to see what changed. What is wrong with the MAF ground on the stock connector?

IIRC the wire was small and prone to breaking. So rather than run a whole new harness wire, they made that to add in a better ground lead. Plug & Play > than wire tracing/splicing.

[Tungsten]

well ill just take good care of it

 

in fact i may redo the entire harness and run it seperately directly to the ECU and ground it straight to the negative terminal on the battery

 

thanks for your input guys, i'm happy with the truck now it runs amazing and picks up faster and sips gas not guzzle it down

 

if your truck hesitates and if you have that piece of @!*% sub harness, delete it and get new wiring to the MAF

remember to always remove the connector when changing the air filter, you will be fine

Edited May 28, 2010 by Tungsten

[Cuong Nguyen]

I have to have an additional ground spliced into my original wire harness as it no longer runs right without it.

[Tungsten]

actually if you put a new connector in there with fresh wires and just splice that to the harness it should work just fine

if you check EC.pdf page 10 from the downloadable FSM, you will see that the ground goes to the ECU to avoid a voltage drop

[msavides]

PART NUMBER: 24079-40F00

ENGINE SUB HARNESS

(NISSAN LIST $32.50)

 

I ordered it through Alkorahil on this forum

 

 

Pm him and he can give you his price for it.

 

 

I have spent almost 3 years trying to get rid of My code 45 (leaking injector) Check engine light. If this POS harness fixes it. I don't care if it is hokey.

 

So far so good. AN interesting thing happed when I installed it. though. For the first 2 miles (until the truck warmed up) my truck missed and spat ans sputtered and was cutting out. I thought crap This thing is doing mor harm than good. Then after it warmed up it was like a switch was flipped and it smoothed out. I have not had a problem yet in over a month.

 

Mark

[adamzan]

These links may help people with the code 45 problem (I had the same thing a while back)

 

http://www.justanswer.com/questions/3akke-i-have-a-1991-nissan-pathfinder-with-a-code-45-leaking-injector

 

Nissan TSB about it:

 

http://ww2.justanswer.com/uploads/2paulm/2010-03-23_170349_TSB.pdf

 

Another TSB:

 

http://ww2.justanswer.com/uploads/2paulm/2010-03-23_170148_poor_ground.pdf

[Tungsten]

I do not recommend using the sub-harness, whoever thought of that is on crack. Just fix the wiring and you will be set. Ever since I removed it, the truck runs much better. I get better fuel economy and better throttle response and my startup issue just went away like magic.

[Tungsten]

I just had the corrosion cleaned out of the connector, the truck runs way better now.

[edicer2]

glade we figured out what it was. Its completly worthles to me mine ran way better with out it. Truck would die everytime i put the clutch in it seemed with it pluged in so if ur having problems take it off

[Jessyj]

I have this awkwardly done MAF wiring. Its one of those angled connectors piggy backed onto another one with a ground coming off the one connected to the MAF. The ground is hooked up to the intake plenum. Is this some factory remedy?

 

 

 

The extra ground goes here...

 

 

Why?!

Quick ? which is ground A B or C on the maf sensor

[Tungsten]

i would have to say B

[Tungsten]

After a closer inspection the problem seems to be a poor ground signal rather than a broken wire so it looks like I will have to re-install that sub-harness there but instead of grounding to the body I will ground directly to the negative terminal on the battery. Or should I run another ground to the ECU?

 

I'm getting a complete loss of power followed by an engine flood when moving from a standstill; the engine bogs down and then springs back up and gets going like nothing happened.

 

I think this is MAF related as I already replaced my coolant temp sensor.

Edited July 9, 2010 by Tungsten

[adamzan]

My truck does the same thing its always in the summer when its humid to and it really pisses me off.

[Tungsten]

OK, so I re-attached the MAF sub-harness back and grounded the MAF sensor straight to the negative terminal on the battery.

 

 

 

Doing this resolved the intermittent flooding issue but the truck does seem to accelerate a tiny bit slower. Less fuel going to the engine?

[adamzan]

Mine doesn't even have one of those boots. No wonder my truck runs like @!*% when it's this humid.

[Tungsten]

The way I see it is that the sub harness not only adds a ground to the MAF sensor, it also adds a new ground to the ECU. I think the problem here is that the ECU has a poor ground connection through the body to the battery which causes a voltage drop and this sub harness actually fixes that. Run the ground wire directly to the negative terminal on the battery for best results.

Edited July 12, 2010 by Tungsten