2015 passat tdi keeps blowing o2 sensor fuse

Davezl900

New member
Joined
Jan 31, 2014
Location
Ontario Canada
TDI
2015 Passat TDI
llo all, i have codes
p0031,

U029E

U029D

P220A

My code reader says o2 sensor short to ground so i replaced the o2 sensor with a new Bosch sensor and still blowing fuses. I assume the codes pertaining to the NOX sensors stem from the fact that the voltage is non existent on NOX sensors due to the blown fuse. Does anyone else have a similar issue? any known wiring short areas or could this be an ECM problem?

Thank you,












u
 

MrCypherr

Veteran Member
Joined
Sep 3, 2012
Location
Ontario
TDI
Mk6 Wagon
I believe since you had the recall done and had the additional NOx sensor added in, with included the additional harness, I've seen a couple of these be solved with an issue with the additional harness they added in to include the second NOx sensor. I dont believe this is a ECU problem. I'd check the harness because it connects to both NOx sensors and I believe the O2 sensor.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
I believe since you had the recall done and had the additional NOx sensor added in, with included the additional harness, I've seen a couple of these be solved with an issue with the additional harness they added in to include the second NOx sensor. I dont believe this is a ECU problem. I'd check the harness because it connects to both NOx sensors and I believe the O2 sensor.
Its a second O2 sensor that is used for NOx compliance.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
It is a NOx sensor, in the pipe in the back, that runs all the way up to that bracket on the battery. If it wasn't routed right...

The kit is dependent on the model, but they all come with the 04L-907-807-CS NOx sensor.

The kit will be something like 8P0298101D (the '298' denoting an exhaust kit) and then the pipe with the threaded bung in it, 5Q0253301H for some models. The kit comes with the NOx sensor, the wiring, the bracket, the exhaust clamps to attach the pipe after a section is cut out, and some screws and zip ties.
 
Last edited:

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
well shoot, I learn something new each day.

Sorry for my ignorance.
 

Davezl900

New member
Joined
Jan 31, 2014
Location
Ontario Canada
TDI
2015 Passat TDI
Thanks very much Folks, I appreciate the input and I will open it up and trace that harness. I've since ordered the rear sensor and it should arrive by the 12th of March but at least I'll have figured out the harness before I install new sensor.
 
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