GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

P0087 Low Fuel Pressure Troubleshooting - VCDS Logs included

Qwoz

Roflcopter pilot
Location
Redmond WA
Car(s)
08 GTI
Ok so I replaced the G247 sensor with the latest revision I could find 06J906051D. You wouldn't believe how tight of a fit it was getting the 27mm wrench behind the intake manifold to get it off. It is a Bosch OEM replacement, however it is a little different from the 06J906051B that it is replacing. The original "B" version was made in Germany and has a black connector, the new one is made in china and has a orange connector. When screwed in the connector is in the reverse position compared to the original (the electrical connector clip is now on the top instead of the bottom).

The new sensor does not help get rid of the P0087 engine code, in fact it introduces a new one :mad0259:. I now get the P0087 and a P119A, for which the description is basically "Fuel Pressure Sensor (G247) Malfunction". Just my luck that the replacement is faulty... However this got me thinking that maybe this new senor is not compatible with my vehicle, and I found this thread on the ross-tech forums:

http://forums.ross-tech.com/showthr...High-Thrust-Sensor-quot-There-is-a-difference!

If I am reading this right, is it possible that this newer version simply does not communicate well with my vehicle since it originally had a "B" revision instead of the "D" replacement? Should I have replaced it with a "B" revision instead of the newer "D" revision?

It seems like my next step should be to put the original G247 back on, or replace with a B revision, and then put my old stock HPFP back on and de-tune to stage 2. I am done spending money on this and I just want the CEL to go away.

Fuel Pressure Sensor (G247)
P119A - 002 - Malfunction - MIL ON
Freeze Frame:
Fault Status: 11100010
Fault Priority: 2
Fault Frequency: 3
Reset counter: 255
Mileage: 134852 km
Time Indication: 0
Date: 2000.00.00
Time: 15:54:13

Freeze Frame:
RPM: 762 /min
Load: 22.3 %
Speed: 0.0 km/h
Temperature: 93.0°C
Temperature: 21.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 14.224 V
 

Qwoz

Roflcopter pilot
Location
Redmond WA
Car(s)
08 GTI
Just ran a few logs while idling to verify that the new G247 is providing a reading even though it is throwing the P119A malfunction code. It appears that it is actually giving me a rail pressure reading, if group 106 is in fact pulling the fuel pressure reading from this sensor. You can see the logs at the imgur link below.

http://imgur.com/a/Ib9yN

In the first picture it is telling me that the actual rail pressure at idle is around 25, but the specified is 50 bar. Is it normal at idle to be this far off, or is the fuel pump seriously under performing at idle?

In the second picture, you can see with a little throttle while stationary the actual rail pressure reaches specified no problem. Also note that the low side seems to keep close to 6 bar, which i think is how it should be.

If the low side is providing enough pressure, but the high pressure side won't stick at 50 bar at idle wouldn't this suggest that it could be the high pressure fuel pump going out? regretfully I don't have these same measurements with the old G247 to compare, the one that doesn't throw the malfunction code.

Also, can anyone tell me if the 58.8% duty cycle in the third image is for the LPFP or the HPFP? I feel that this is a high value for idling.
 

high_octane3541

Go Kart Champion
Location
McKinney, TX
58.8% duty is too high at idle.

Your high pressure isn't meeting requested so the ecu is trying to compensate for that by making the lpfp work harder.

You should also do a log with "spirited" driving instead of just stationary. The load is different.

Do a log with RPM, block 230 and 231
 

tedted

Newbie
Location
CA
Ok so I replaced the G247 sensor with the latest revision I could find 06J906051D.

Fuel Pressure Sensor (G247)
P119A - 002 - Malfunction - MIL ON
Freeze Frame:
Fault Status: 11100010
Fault Priority: 2
Fault Frequency: 3
Reset counter: 255
Mileage: 134852 km
Time Indication: 0
Date: 2000.00.00
Time: 15:54:13

Freeze Frame:
RPM: 762 /min
Load: 22.3 %
Speed: 0.0 km/h
Temperature: 93.0°C
Temperature: 21.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 14.224 V

Unless something changed in the last 72hours, you still have the wrong version. When I called the dealership I was told the most recent revision is "C" and it comes in a black housing. That is the one I used to replace mine, unfortunately like you my P2177 code returned yesterday so that means this was a wasted amount hoping this would fix the issue.
 

Qwoz

Roflcopter pilot
Location
Redmond WA
Car(s)
08 GTI
Unless something changed in the last 72hours, you still have the wrong version. When I called the dealership I was told the most recent revision is "C" and it comes in a black housing. That is the one I used to replace mine, unfortunately like you my P2177 code returned yesterday so that means this was a wasted amount hoping this would fix the issue.

Crap, thanks for chiming in. From the little info I can scrape up on this topic it sounds like the "D' revision I got is for the TFSI, not the FSI. Its not very clear because many places says the "D" sensor is for GTIs dated back to 2007, and mine is a 2008.

On a side note, if you plan to switch back to your old pressure sensor, maybe I should buy the revision C from you lol.
 

tedted

Newbie
Location
CA
I have a 2006 TFSI i think. When I called the dealer and gave them my vin they said the "C" was the most updated revision. I dont plan on swapping back out as I paid to have it installed on the guidance from the local indie shop and like I said it didnt fix anything which kind of makes me mad because i really had a feeling it wasnt going to solve the problem as my older sensor was reading just fine according to vcds.
 

Qwoz

Roflcopter pilot
Location
Redmond WA
Car(s)
08 GTI
I have a 2006 TFSI i think. When I called the dealer and gave them my vin they said the "C" was the most updated revision. I dont plan on swapping back out as I paid to have it installed on the guidance from the local indie shop and like I said it didnt fix anything which kind of makes me mad because i really had a feeling it wasnt going to solve the problem as my older sensor was reading just fine according to vcds.

I suppose if you had a shop do it would be more a hassle to swap it out. My thought was if the sensor didn't fix your problem, then the old sensor is probably fine and you could sell the new one.

If you have a 2006 it would be FSI like mine.
 

Qwoz

Roflcopter pilot
Location
Redmond WA
Car(s)
08 GTI
Just got off the phone with the parts department at my dealership and they said 06J906051D would be the latest revision for my 2008 GTI, and that the C revision was actually never designed for the GTI.... weird. This seems to be contrary to what I have read online... I'm actually thinking the service guy doesn't know what he is talking about. Check out this article I found on linkedin. This seems to be the exact situation I am running into. Note the table at the top, it would suggest the D revision is not for my car, and the C version might be.

https://www.linkedin.com/pulse/g247-high-pressure-fuelrail-sensor-20l-audivw-jb-light
 

high_octane3541

Go Kart Champion
Location
McKinney, TX
Don't pay attention to the fsi and tfsi crap. Here's an easy way to remember,

Oil filter access from under the car = fsi

Oil filter access from the top = tsi
 

Qwoz

Roflcopter pilot
Location
Redmond WA
Car(s)
08 GTI
An update. I have put the old G247 high pressure sensor back on and I no longer get the malfunction code, and the car drives MUCH better. I logged the high pressure side fuel pressure at idle again, and this sensor is reading out around 37 bar (actual) instead of 25 bar as the previous sensor had. This is still below the 50 bar that is being requested at idle, so it could still be a sensor issue, but I am now leaning more toward it being a HPFP issue. I will swap the HPFP back to my stock pump this weekend and see what we get.

It would be useful to know what actual fuel pressure other forum members are getting at idle on the high side (log Block 230). Specified is 50, and both senors I have used are reading below. Right now I am not sure if it is normal for the actual fuel pressure to be below specified when at idle. All I know is that this is likely what is causing the P0087 code.

I will try and run some WOT logs before swapping the HPFP if I find time.

Another random observation; when at idle when I first turn the car on the low pressure side (block 231) is at 4.8 bar and about 50% duty cycle. It will stay like this until i blip the throttle. It will then drop for a second, and then the LPFP pump will get louder and go up to and idle at 5.8 bar and 56 - 60% duty cycle. I believe this is the low pressure side trying to compensate for a sag in fuel pressure on the high pressure side -> leading me to believe the HPFP is not keeping up.
 

Qwoz

Roflcopter pilot
Location
Redmond WA
Car(s)
08 GTI
Finally fixed update. So I decided to swap my stock HPFP back on to the car and set it to the stock tune. Check engine light is now gone for 500 miles, and the whining from the in tank fuel pump is resolved as well. In hind sight this should have been my first course of action. For the winter I will probably just keep the stock tune and look for a new upgraded HPFP for the summer. Learn from my mistakes!

TLDR: It was a faulty HPFP. For reference I am told it was a "HPFP Upgrade" brand pump. I bought it used so no real way of telling.
 
Top