Pink wire mod explanation

[Lookey1989@hotmail.com]

Hi everyone,
How are we all? Ok so I’ve recently stumbled across the “pink wire mod” which I understand is soldering a resistor 6.2k ohm .5w inline with the pink wire to the Maf. From what I’ve read it will prevent the engine light appearing after an egr blank. So the question how does that work if it does? Has anyone done this? I think the pink wire is the temp for the maf but after that I’m lost.
I’d like to learn how this works before even considering doing it.
I’m not looking for an egr debate please guys, it’s all food for thought atm.
Cheers guys tia.
Luke

[mudski]

I've heard the same but haven't actually read it done. Can you post a link of where you aw this?

[pollenface]

From all I've read on forums regarding this, I'm guessing that after doing the mod the ECU reads the air temp as being TOO HOT to open the EGR valve so it keeps the turbo boosting all the time instead.

Welcome to the forums!

[Gus-patrol]

After searching high and low to understand how it works, I've pieced this together (all borrow of others, thanks 😊)

There is an inlet air temperature sensor built into the CRD MAF sensor. The ECU uses this temperature measfurement to determine whether the EGR should be activated or not. At low ambient temperatures the EGR is deactivated and by adding a resistor in the temp sensor circuit you “trick” the ECU into thinking the ambient air temp is too low for EGR operation.

Initially a 6.2K was used as the guy figuring it out used "what I had in the bench tray" that was close enough to achieve what was needed.

According to the graph in the ESM, the change in resistance vs temp is logarithmic, so 6.2kOhm vs. 6.8kOhm only makes ~5degC difference. Anything between 6kOhm and 10kOhn should trick the ECU into thinking the ambient is less than 0degC so should do the trick.

Spounds like lot of investigation was done by people plaung in the ECU and they could not find any other system that uses this temp sensor signal so modifying it does not affect anything else.