# How to Replace Fuel Pressure Sensor in 2.0 TFSI



## NJDSG (Apr 24, 2018)

New member here.

I'm dealing with a P0087 code and an engine that starts and then immediately dies. I replaced the fuel filter, and next I'm going to put in a new fuel pressure sensor. It's fairly straightforward, except for how to reduce the fuel pressure, as there's no Schrader valve on the high pressure pump or anywhere else to easily do a controlled release. So my question: Has anyone else done this sensor replacement? And if so, where in the fuel system did you release the pressure?


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## poder (Mar 18, 2015)

Welcome 

Under normal circumstances, you could pull the fuel pump fuse, and then start the engine and let it run until pressure is low. That of course gets difficult if the engine does not run ;-)
Just leaving the car overnight might drop the pressure enough though. You still might want to pull the fuse, as opening the driver side door or putting ignition on will pressurize the system.
How did you de-pressurize the system when changing the fuel filter then?


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## NJDSG (Apr 24, 2018)

Thanks for the reply.

Before replacing the fuel filter I removed the gas cap. My concern was that the pressure at the point of the sensor would be higher/too high for that to be sufficient. But sounds like I should be ok if I remove the cap, pull the fuse, and then back out the sensor a little bit to release any residual pressure into a rag before removing completely.


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## Barr_end (Oct 19, 2016)

There is a valve on the high pressure fuel pump on the TFSI, what year is your TT, its located on the right (if facing the front of the car) of the fuel pump facing at a 45 degree angle down with a plastic retaining cap. This can be used to drain the pressure out of the area where the sensor is located. Same procedure as you would when replacing the cam follower. Still best to leave the bonnet open and the car overnight if possible so the low pressure pump in the tank isn't activated by the drivers door opening.


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## NJDSG (Apr 24, 2018)

My TT is a 2009. I didn't see a valve, but I'll look more closely in the area you describe. Thanks.


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## NJDSG (Apr 24, 2018)

Unfortunately, there's no Schrader valve on my pump.


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## NJDSG (Apr 24, 2018)

I replaced the sensor yesterday. The pressure wasn't an issue, but maneuvering a socket into the available space was a challenge to put it mildly. Still need to see if it addresses the fault and non-start.


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## NJDSG (Apr 24, 2018)

The new fuel pressure sensor didn't do the trick.

I just pulled the high pressure fuel pump to see if there was anything obviously wrong with it. Seems fine, as does the roller cam follower. I also used the VCDS input test for the regulator, and it made the clicking sound it's supposed to.

At this point, I could use some direction. To recap, the car starts and dies, so some fuel is getting through, but not enough. The code is P0087 (see below for a few other readings I took), and I've replaced the fuel filter and pressure sensor. I'm tempted to just replace the high pressure pump, since this seems to be the most common cause of P0087 in the 2.0 TFSI, but it's not a cheap thing to take a gamble on. Of course, I'm also wondering if it could be the low pressure pump and/or the relay, but that seems less likely (from what I've read).

Thanks in advance for any wisdom that can be shared.

Address 01: Engine (8J0 907 115 M)

16:17:56 Group 106: Fuel Injection (Fuel Supply System)
40.00 bar Fuel Rail Pressure (spec.)
6.50 bar Fuel Rail Pressure (actual)
79.6 % Fuel Pump Duty Cycle
76.0°C Fuel Temperature (calculated)

16:17:56 Group 140: Fuel Supply System (Quantity Control Valve)
94.4° Quantity Valve closing Angle
-59.2° Quantity Valve opening Angle
6.50 bar Fuel Rail Pressure (actual)
01 Quantity Control Valve Status

16:17:56 Group 230
1.01 (no units) 
-1.000 Difference 
-1.000 Difference 
11010101 Bin. Bits


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