G450 replacement

What is required to replace the G450 - VW Volkswagen Diesel G450 DPF Differential Pressure Sensor

There are 2 sensors, G450 and G451. one is behind the oil fill cap and has a little thermal blanket around it to protect it from the heat. the other is on a bracket above the intermediate pump. Passenger side by the strut mount. Which one is 450 and 451 depends on your build date. VW has changed the designations of which is which a couple times so you will see conflicting info. The one that usually fails is the one by the oil cap in the high heat area. There have been problems with sensor replacements. There is a type 'A' and type 'B' sensor. It seems VW says they are interchangeable but many have had the new sensors fault out when changing the type 'A' with a type 'B'. and the type 'A' sensors are hard to find. I replaced my G451 type 'A' (by the oil cap) about 2013. I have a very early model 2010.

After replacement the sensors need to be adapted to the car with VCDS. (Let the ECU know there is a new sensor so it can see the new null starting point)

Someone here might be able to give you better specific info on which ones you have and location if we know what car model you are asking about. Good luck. I have had no issues since my sensor replacement.

Oops my mistake. Looking back in my history, my car has the 'B' sensor and that's what I put back in. The transition from A to B was done in late 09 model year.

check out this thread and the link to another thread with pics on page 2

http://forums.tdiclub.com/showthread.php?t=412579&highlight=g450

you need the sensor, Torx bits and triple square bits, and some good hose clamp pliers.

a mirror helps identify which fastener is where. and a flashlight helps too.

careful with the electric connector, it is easy to get frustrated and break it.
push the connector in, release the tab, then it should pop right out.

If you don't reset the values, the car will do so in its own sweet time.

Thanks for everyone's response.

This is my daughter's car, she lives an hour away.
I was able to look at her car again earlier today.
The car drives fine, but still has the same error code, P2002 :
1 Fault Found:
008194 - Particulate Trap Bank 1
P2002 - 007 - Efficiency Below Threshold - MIL ON
Freeze Frame:
Fault Status: 11100111
Fault Priority: 2
Fault Frequency: 7
Reset counter: 255
Mileage: 156835 km
Time Indication: 0
Date: 2058.14.06
Time: 19:42:17

Freeze Frame:
RPM: 1564 /min
Speed: 13.0 km/h
(no units): 45.9
(no units): 20.4
(no units): 1.78
Pressure: 51 mbar
Pressure: 26 mbar

I found the location one of the the Exhaust Pressure Sensors, just to the left of the oil fill cap. Where is the second Exhaust Pressure Sensor located.

Just for grins I re-ran VCDS and had the same results, P2002 - 007 - Efficiency Below Threshold - MIL ON.

As a test, I cleared the codes and restarted the engine and took a 2 minute drive. The Check Engine Light was still on. I expected there to be some delay, however short, before the CEL back came on. When I restarted the car the CEL was on immediately, it was as if the CEL was not cleared.

I thought the fact that it came back instantly might have some significance to the diagnosis. If there is some some significance to the CEL coming back on instantly our friends at TDIClub would have that information.

Any suggestions?

The P2002 fault code is not a G450/451 sensor issue. those sensors usually throw codes P047. P2002 is usually found to be a bad DPF. But usually if you clear the code it will take a while to come back on. So I wonder if there is a wire or line pulled loose. Unless the DPF is very plugged. How long has it been driven with the P2002 code.

if you want to look closer, print out these sheets and run a couple of the basic settings to look closer at how systems and sensors are performing.

the differential DPF pressure is of interest, as are the cycling comparisons.

run through all the basic settings options you can find, and record (or save) readings. try to capture the options. some tests cycle back and forth between two conditions.

you can post results here for comment.

(a guess is you could have a leak in a pressure line to the sensor...)

Any soot in the tail pipes?