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LifeOfDesire

Unplugging the MAF on a 525d

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Currently I have a problem no garage seems to be able to diagnose, where the car hesitates significantly at random moments on acceleration when the MAF is plugged in. If I drive the car with it unplugged it goes away completely, but obviously it uses more fuel and there is little power below 2k RPM. From what I have read so far unplugging the MAF disables the MAF sensor, MAP sensor, and EGR activation. I have replaced both MAF and MAP sensors, and plugged the vacuum tube on the EGR so it stops working, but the hesitation still occurs. It also occurs with the MAF plugged in and with the MAP unplugged so I do not believe it is the MAP at the moment.

 

I am looking for a full list of what unplugging the MAF actually does so I can try and narrow down what is causing the problem. Thank you!

Edited by LifeOfDesire

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I had an odd hesitation around 2k.  Typically would happen with constant throttle input, going up a hill and the car would upshift.  Load would fall and the car would slwo down, needing more throttle input.  It's always done it (had vacuum lines, new MAP, new MAF, all healthy).  Now I've remapped it it no longer does it at all. 

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Looks like I'm going to have to test the wiring then. Could the hesitation be something to do with the battery voltage? Mine often reads 13.5V which is low and the battery has been flattened several times in the past few years. I don't think the charging capacity is that high either. @Clavurion It says on that link the DDE supplies the MAF with battery voltage so if the battery is knackered could it be interfering?

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