Exhaust Gas Temperature Sensor, Bank 1 sensor 1.

[petrolhead63]

Hi, 2009 A3 170bhp quattro. Bank 1 snsor 1 EGT sensor is giving fault codes. Where is this physically on the system please and how to I access it to change?
There are three different colour plugs traced on the wiring.

[Crasher]

Which engine code, BMN, CBBB or CFGB? Sensor 1 is before the turbo, it only has one bank.

[petrolhead63]

Hi Crasher, sorry for not getting back and now deciding to resurrect this one! The car got parked up in a disgrace for a while after I concluded it is an evil to reach sensor under the DPF/turbo area that even my skinny arms could not reach! Seeing as the car is in limp mode and it also has the DPF light come on I have also concluded it needs more work and may need the DPF in any event.
The engine code is CBB and now I have sorted our other car I am back to this one.
By pulling the plug on that evil to reach sensor (black plug) and plugging in the new unfitted sensor I can clear the code, start the car and keep the sensor code clear so that seems to be correct. If i reconnect the sensor in the exhaust the fault code re appears.
I now need to move on to the dpf....which may have fouled up due to the sensor fault issue??

[Crasher]

The thing to be aware of when taking these sensors out is they can gall as the sensor is wound out and suddenly stick and the only option is to drill it out after cutting the top off and as the thread will be ruined, an insert has to be fitted, that is if you can find a drill bit that will cut the incredibly hard steel used.

[petrolhead63]

Yikes! thanks for the heads up, if it goes tight work it back in and out then.
I took the heatshield off the DPF and can get my hand round to the sensor but in no way could I safely get a tool on to the hex. I am sure there is a way....but will now look into the DPF light on, pressure sensor etc and see if we can get it out of limp mode first.
If the DPF has to be removed the temperature sensor will be easier to do in any event.
Beastly thing to work on! prefer my oldies haha

[Crasher]

Nope, if it goes tight you are stuffed, it won't go back, I have tried oxy heat, induction heat, every spray known to man and the only solution is chop and drill. I had this happen on a A6 Ultra and so we fitted a new B&M DPF of the best quality type. After weeks of the light coming on, spending hours doing multiple regens and then three new DPF's under warranty we gave up, repaired the old DPF, had it cleaned, re-fitted it and now happy. NEVER will I touch an aftermarket DPF again!

[petrolhead63]

OK, I am losing the will with newer cars haha! anyway. The sensor is changed and we get no fault codes on them now...so it is on to the DPF issue.
So far we have used a good quality Snap On scanner I have access to but not VCDS.
The DPF light is on, its in limp mode, it also has the glow plug light flashing and the MIL light on.
The scan only shows DPF fault now, so we scanned for DPF and possible regen. Soot load was within what Snap on said would work so we have been through the regen process. It says it has done it, as previously the last successful regen was over 2000km ago and now it is under 40km so done on our driving up and down the A3!
The car is still in lim with DPF light on etc, am I at a point it needs a VCDS diagnostic to get it reset out of limp etc?
Thanks for any guidance.

[Crasher]

I often run into problems doing a regen even with VCDS and have to resort to the VAG system ODIS.

[petrolhead63]

ok, that sounds like bad news! should it automatically come out of limp mode after the regen? or does it take another reset/code clear?? I have found somebody nearby with VCDS prepared to have a look. The only fault code coming up now is the DPF, all temperature sensors seem fine.

[Crasher]

If a non forced regen succeeds, it will come out of limp mode. You need to see what the soot and ash figures are in measuring blocks, proper VCDS has label files and display searches for this.