DPF Differential pressure sensor

[666markyboy]

Hi all.... new to the 8P chassis but not this forum or Audis so sorry if this has been covered before...
last weekend the Mrs and I treated ourselves to new cars, to us anyway ....Myself an A4 B8 Avant Quattro Tdi 2.0, and the wife a A3 8p Quattro 2.0 tdi..... both great cars and sporting the same 2.0 170 tdi engines..... however after a short while on the wifes 8P the engine management light started coming on every now and then ....not all the time,,, I scanned the car with Torque and it's showing a low circuit on the Differential pressure sensor....i'm waiting for a proper VCDS scan next week but in the mean time I thought I would take a nosey under the bonnet and spotted this.... one of the pipes on the sensor just appears to go straight to atmosphere ,,,, On my car the pipe seems to lead down the back of the engine somewhere.... so should this tube be connected to something ? and if so what ??.... thanks in advance

Regards Mark

 

[Darren92]

That's normal on some engine configurations.

 

[666markyboy]

Ok.... thanks, there's nothing near by that looks like it should be connected to it so I was kind of thinking it looked normal.... I note it's a Spanish part so maybe a cheap replacement for one that failed before... I'll prob swap it out for a new one and see what happens

 

[Darren92]

Always buy the OE part from Audi or TPS.

 

[T8DPR]

"Last weekend"?? I would imagine you're covered by warranty unless you've bought private, if so get the garage you bought it from to sort it, you don't have to pay a bean

 

[desertstorm]

The small open ended pipe is the atmospheric pressure measurement side. It points down and is short to try and stop anything finding it's way back into the sensor. The differential pressure sensor is a fairly common part that fails. The problem is when they do the car is less likely to regen correctly. This sensor measures the pressure drop across the DPF that is directly related to how blocked it is. If the sensor isn't reading correctly the ECU won't know the state of the DPF and this can lead to the DPF becoming blocked. Sort it out sooner rather than later.

 

[666markyboy]

"Last weekend"?? I would imagine you're covered by warranty unless you've bought private, if so get the garage you bought it from to sort it, you don't have to pay a bean

Yes it came with a comprehensive Waranty but I'm waiting to get it properly scanned first, I like to know whats going on with my cars before I let anyone loose on them,,, ultimately if it is the sensor I wont be paying for it

The small open ended pipe is the atmospheric pressure measurement side. It points down and is short to try and stop anything finding it's way back into the sensor. The differential pressure sensor is a fairly common part that fails. The problem is when they do the car is less likely to regen correctly. This sensor measures the pressure drop across the DPF that is directly related to how blocked it is. If the sensor isn't reading correctly the ECU won't know the state of the DPF and this can lead to the DPF becoming blocked. Sort it out sooner rather than later.

This is what I suspected, Thanks