LikMyWagon

Hi I've been searching the web on this topic and I could use a little help. I'm trying to diagnose a P0089 (VAG P310B) code on my 2007 Audi A4. I've already replaced the HPFP, G410 and the fuel filter and had some other diagnostics done at the Audi Dealership. I've been told, by Audi, it's either the LPFP or the Fuel Pump Control module. Wasn't exactly sure what the control module was until I read some more posts. I did a short test run logging blocks 101, 103 and 106 with VCDS. Is it odd that the LPFP only ran an electrical % between the 83% at 12% engine load (idle) and 94% electrical at an engine load of %167 (WOT)? I've read elsewhere that the LPFP at idle should be about %50 and if it isn't it's shot but couldn't the module be the problem telling the pump to run at that rate at idle, especially since it doesn't hit 100% at WOT and seems to drive fine? The dealership did some pressure checks and they seemed ok as well.

There aren't any real driveability issues except maybe a little uneven power at full throttle with a cool (but not cold) engine that seems fine when it's at full temp. The check engine light sometimes clears itself and I've had the cam follower checked so I'm not too worried about driving it for now I just hate having the MIL on. I have the .CSV file from the test run but I don't see how, if at all I can attach it to this post but here is a snapshot at idle FWIW.

9:04:24 Group 101
720 /min Engine Speed
12.8 % Engine Load
0.77 ms Median injection timing
1.75 g/s Intake Air Mass

19:04:24 Group 103
4.75 bar Current Fuel Pressure
4000 Fuel Pressure Regulator
3000 Adaptation Value elect. Fuel Pump
ADP. Run Demand controlled Fuel Pump Adapt.

19:04:24 Group 106
49.96 bar Fuel Rail Pressure
82.7 % Electrical Fuel Pump 1
Electrical Fuel Pump 2
655.35 s Time Everyone with P0089, I suggest that you check the fuel pressure at the fuel rail if you have VAG-COM:

Checking Fuel Pressure

Prerequisites:

* Ignition ON
* Engine ON (Idle)
* System voltage at least 11.0 V.
* Coolant Temperature at least 80 °C

[Select]
[01 - Engine]
[Meas. Blocks - 08]
Group 103
[Go!]
Field 1: Fuel Pressure (Low), Specification: 2800...7200 mbar
Field 2: Fuel Pump Adaptation, Specification: -1000...+1000 %

Group 140
[Go!]
Field 3: Fuel Rail Pressure (High), Specification: 25.0...110.0 bar
Increase the Engine Speed while checking this value, the Pressure has to rise with the Engine Speed.

Group 230
[Go!]
Field 1: Specified Fuel Rail Pressure (High)
Field 2: Actual Fuel Rail Pressure (High), Specification: 25.0...110.0 bar
Field 3: Deviation between specified and actual fuel pressure, Specification: max. 5.0 bar

[Done, Go Back]
[Close Controller, Go Back - 06]

"3. Run Basic Settings 103 to adapt system."

Fuel Pump
Prerequisites:


Ignition ON
Engine ON
System voltage at least 11.0 V.


[Select]
[01 - Engine]
[Basic Settings - 04]
Group 103
[Go!]
Activate the Basic Setting.
[ON/OFF/Next]
Wait until Field 4 shows "ADP. O.K.".
[Done, Go Back]
[Close Controller, Go Back - 06]