2015 Q7 EGR/EGR cooler problems

grapplermi

Member
Joined
Nov 1, 2022
Location
Ohio
TDI
2015 Audi Q7
hello all, I recently retired from the Army and bought a used 2015 Q7 for my wife to have a nice daily driver. We got about 20k enjoyable miles out of it and then it went into limp mode on me driving back home from Columbus. Couldn't get above 2k RPM, but ran normal besides that. Check engine light cam on and the curly spring symbol that I relate to glowplugs. Had it scanned at a buddy's shop and it said EGR. Went to Audi dealership and bought a new one, installed. Got about 50 miles out of it, then it all happened again; check engine, limp, EGR codes. Took it to Audi and dropped it off. They had a look and said I must have gotten a bad EGR from them, they replaced, free of charge. I'm happy. Drive it home and the same thing happens again! Drop it back off at Audi and they look and look. They had my Q7 for a total of 2 months! They finally call and say it's the EGR cooler and it would be $4000 for them to replace. I laughed at them and then picked it up and waited another month to get it into a Euro luxury car specialist shop to replace the ERG cooler for $600 and I bought the EGR cooler from an Audi dealer online for $600. I get it back today and the Sonofab$^&% does the same thing on the way home!! I don't really know what to do now. Has anyone had these problems? Could it be whatever tells the ECU that the EGR/cooler is bad? ECU? I'm lost here and hoping someone has had the same problem and won.

standing by! thanks, Matt
 
Last edited:

ticaf

Veteran Member
Joined
Nov 15, 2018
Location
US Mid-Atlantic
TDI
Stock 2015 Golf SW S Manual TDI
Help us help you here, what are the codes?
Unfortunately, not too many mechanics know those TDIs. Check out for the gurus on this websites.
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI, 13 Porsche Cayenne V6 TDI
Cracked DPF will cause EGR codes when it starts clogging stuff up. Needs better diagnosis.
 

grapplermi

Member
Joined
Nov 1, 2022
Location
Ohio
TDI
2015 Audi Q7
yep, I was looking for them when I did my original post. They were/are:

P040300 -Exhaust Gas Recirculation Circuit
P012800 - Coolant Thermostat (temperature below Thermostat regulating temperature)
P019100 -Fuel Rail Pressure Sensor "A" Circuit range
VAG02446 - Drive, mechanical malfunction

I'll have a good look at the DPF, thank you.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Surprised this is not under warranty. Either it was never "fixed", or it has a LOT of miles on it.

It would normally be 10 year/120k miles from new (original in-service date), plus 4 years/48k miles from modification, whenever it was done.

Most 2015s would still be under 120k miles still, but some are not.
 

grapplermi

Member
Joined
Nov 1, 2022
Location
Ohio
TDI
2015 Audi Q7
Yes, loads of miles. It was an oilfield exec's car in Texas and Audi said the modification happened around 102k, it is currently sitting at 167k.
 

joep1234

Veteran Member
Joined
Jan 2, 2014
Location
NC
TDI
former '04 Beetle TDI, now 2x '15 Audi Q5 TDI's, 2007 Dodge Ram 4x4 6.7
My wife's 2015 Q5 had the same problem. Generic scanner said bad EGR valve. They kept it at the Audi dealership for 2 weeks and got it back fixed now for almost 2 years. It was the EGR controller unit that controls all of the EGR functions. Her car only has 66k on the clock and it was covered under the extended warranty.
 

grapplermi

Member
Joined
Nov 1, 2022
Location
Ohio
TDI
2015 Audi Q7
Glad it worked out for you. I had it at a German car specialist and he wanted to do the control and the harness, which Audi should have done instead of my Cooler, but said it was gonna be $1400 total. I have decided to delete and tune. Parts all come tomorrow and I'm replacing exhaust on Wednesday. Pretty exciting!
 

grapplermi

Member
Joined
Nov 1, 2022
Location
Ohio
TDI
2015 Audi Q7
closure. Did the exhaust and tune. Unbelievable how good she is running. I went with a stage 1 and it has a huge amount of power and runs very smoothly. No lights, no flutter, no problems. If I could keep my foot out of it, the mileage would be better, too. I'm averaging around 32mpg, calculating manually.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
32 MPGs out of something that big and heavy (and AWD!) is pretty amazing. Only get those numbers with a diesel! My 1.8t 4Mo B5 Passat wagon struggles to get 25.
 

ritsco

Veteran Member
Joined
Dec 5, 2005
Location
Northeastern CT
TDI
2015 TDI GSW SEL and 2006 Golf TDI GLS
@grapplermi,

Did you do the Malone tune or something else? Did you just do software or a combination of software and some bypass pipes? I am just looking for how this is done to make my newly acquired 2015 Cayenne Diesel more reliable. I am contemplating a tune to get rid of the requirement to constantly clean the soot buildup in the intake. My fear is passing emissions in my state (CT) post tuning.
 

grapplermi

Member
Joined
Nov 1, 2022
Location
Ohio
TDI
2015 Audi Q7
hiya ritsco, I did the Malone tunes, stage 1 and removed the DPF and CAT sections of the exhaust; replaced with pipes from Rawtech. The tune deleted the EGR, DPF, and DEF. It is an absolute rocket ship now and no codes. Great MPG.

As far as emissions testing, I am no expert. I would think it would pass if you left the filter and cat on, but changed the tune back to stock for the test. Kinda limits the results you'd get from opening the exhaust up by removing the restrictions, but if it means you pass, then you might have to do it.
 

ritsco

Veteran Member
Joined
Dec 5, 2005
Location
Northeastern CT
TDI
2015 TDI GSW SEL and 2006 Golf TDI GLS
Thanks for the response. I guess what I am asking is, if I leave those items in place (DPF and CAT), but do the tune and software delete, do I run the risk of crapping up the system in anyway? I tuned my 2004 Golf TDI, but that is a different, and far less complicated animal than my Cayenne.
 

ritsco

Veteran Member
Joined
Dec 5, 2005
Location
Northeastern CT
TDI
2015 TDI GSW SEL and 2006 Golf TDI GLS
Has anyone done the software only tune and lived with it for a while (like 10K + miles or so)??
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI, 13 Porsche Cayenne V6 TDI
Thanks for the response. I guess what I am asking is, if I leave those items in place (DPF and CAT), but do the tune and software delete, do I run the risk of crapping up the system in anyway? I tuned my 2004 Golf TDI, but that is a different, and far less complicated animal than my Cayenne.
Almost nothing in the way of emissions on that 04. Can't get away with a software delete without the hardware portion - at least not for very long. Do it - you'll love it. I saved all my hardware assuming I'd have to reinstall annually for testing, but I have not needed to.
 

ritsco

Veteran Member
Joined
Dec 5, 2005
Location
Northeastern CT
TDI
2015 TDI GSW SEL and 2006 Golf TDI GLS
Yeah, the 04 is nice in that respect and also easy to fix. Thanks for all info !
 
Top