Hello,
I have been following a thread in the "support" forum, however it wont let me post there yet as i am apparently not yet verified. anyway. here's the background. GF's car popped the P2404 code a few years ago. She took it to local mechanic who replaced the LDP twice, and of course that didn't solve the problem. Well, somehow they made it pass smog, but of course the check engine light was never off for long. Come 2 years later, vehicle registration is due again, and hence we have to smog it again.

So far I have done the following.
1) replaced J757 fuse
2) verified resistance in LDP pump was as specified in manual.
3) i am currently renting a Ross Tech cable. I have run the 071 test multiple times. First few times it aborted. A couple weeks later, i was able to work on car again. Performed the 071 test with the N80 line crimped. Aborted the test 2 times. Next I ran without the crimp on the N80, and it passed. So now i'm even more confused.

here's the autoscan. any advice is appreciated.

Code:
Thursday,25,May,2017,19:37:01:17781
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 17.1.3.0 (x64)
Data version: 20170320 DS267.7
www.Ross-Tech.com


VIN: WAUDH74F56N103506   License Plate: RUNNING
Mileage: 150800km-93702mi   Repair Order: 


Chassis Type: 4F (4F0)
Scan: 01 02 03 05 07 08 09 0E 0F 15 16 17 19 42 46 47 4F 52 53 56
          61 62 65 72 77

VIN: WAUDH74F56N103506   Mileage: 150800km-93702miles

00-Steering Angle Sensor -- Status: OK 0000
01-Engine -- Status: Malfunction 0010
02-Auto Trans -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
05-Acc/Start Auth. -- Status: OK 0000
07-Control Head -- Status: Malfunction 0010
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: OK 0000
0E-Media Player 1 -- Status: OK 0000
0F-Digital Radio -- Status: Malfunction 0010
15-Airbags -- Status: Malfunction 0010
16-Steering wheel -- Status: Malfunction 0010
17-Instruments -- Status: OK 0000
19-CAN Gateway -- Status: OK 0000
25-Immobilizer -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
47-Sound System -- Status: OK 0000
4F-Centr. Electr. II -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
53-Parking Brake -- Status: OK 0000
56-Radio -- Status: OK 0000
61-Battery Regul. -- Status: Malfunction 0010
62-Door, Rear Left -- Status: OK 0000
65-Tire Pressure -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
77-Telephone -- Status: OK 0000
 
-------------------------------------------------------------------------------
Address 01: Engine (AUK)       Labels: 06E-910-559-BKH.lbl
   Part No SW: 4F2 910 559 B    HW: 4F1 907 559 A
   Component: 3.2l V6 FSI         0030  
   Revision: --H15---    Serial number:               
   Coding: 01050109190F0120
   Shop #: WSC 22162 444 53437
   VCID: 2B556E758A4045196C-807E

1 Fault Found:
009220 - EVAP Leak Detection Pump Sense Circuit 
               P2404 - 006 - Implausible Signal - MIL ON
             Freeze Frame:
                    Fault Status: 10100001
                    Fault Priority: 4
                    Fault Frequency: 254
                    Reset counter: 40
                    Mileage: 137912 km
                    Time Indication: 0
                    Date: 2016.03.02
                    Time: 12:13:32

             Freeze Frame:
                    RPM: 1440 /min
                    Mass Air / Rev.: 103.6 mg/str
                    Temperature: 31.5°C
                        Overrun
                    Voltage: 14.08 V
                    Speed: 44.0 km/h

Readiness: 0000 0000

-------------------------------------------------------------------------------
Address 02: Auto Trans        Labels: 09L-927-760.lbl
   Part No SW: 4F2 910 156 D    HW: 09L 927 156 A
   Component: AG6 09L 3,2 FSI USA 0010  
   Revision: --H01---    Serial number:        4104086
   Coding: 0000002
   Shop #: WSC 02325 785 00200
   VCID: 26439F4191A27871B3-8072

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes        Labels: 4F0-910-517.lbl
   Part No SW: 4F0 910 517 L    HW: 4F0 614 517 L
   Component: ESP 8.0 quattro H04 0090  
   Revision: 00000000    Serial number: 00000000000000
   Coding: 0020895
   Shop #: WSC 02325 785 00200
   VCID: 2D51606DB4544B2972-8078

No fault code found.

-------------------------------------------------------------------------------
Address 05: Acc/Start Auth.        Labels: 4F0-910-852.clb
   Part No SW: 4F0 910 852     HW: 4F0 905 852 B
   Component: FBSAUDIC6 ELV   H31 0180  
   Revision: 30070501    Serial number: 10600700278780
   Coding: 0000011
   Shop #: WSC 02323 785 00200
   VCID: 63C5C655A210CD5994-8036

   Subsystem 1 - Part No: 4F0 910 131 J
   Component: FBSAUDIC6 EZS   H45 0070

   Subsystem 2 - Part No: 4F0 910 220 A
   Component: FBSAUDIC6 IDG   H39 0040

No fault code found.

-------------------------------------------------------------------------------
Address 07: Control Head        Labels: 4F0-910-7xx-07-H.clb
   Part No SW: 4F0 910 731 B    HW: 4E0 035 729 
   Component: Interfacebox    H43 1190  
   Revision: 00000000    Serial number: 303J$057509997
   Coding: 0000003
   Shop #: WSC 02323 785 00200
   VCID: 21498C5DF88C9F49C6-8074

   Subsystem 1 - Part No: 4F0 910 609 E
   Component: Bedienteil MMIC6H08 0050

   Subsystem 2 - Serial number: 00000000262891

   Subsystem 3 - Serial number: 0125.10.050000000100010671˙

   Subsystem 4 - Serial number: 010671˙

1 Fault Found:
01317 - Control Module in Instrument Cluster (J285) 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 5
                    Fault Frequency: 36
                    Reset counter: 147
                    Mileage: 144896 km
                    Time Indication: 0
                    Date: 2016.08.14
                    Time: 15:48:59

             Freeze Frame:
                    Bin. Bits:       10


-------------------------------------------------------------------------------
Address 08: Auto HVAC        Labels: 4F0-910-043.clb
   Part No SW: 4F0 910 043     HW: 4F1 820 043 S
   Component: KLIMABETAETIGUNGH12 0160  
   Revision: 00000027    Serial number: 00000000199279
   Coding: 0524326
   Shop #: WSC 02325 785 00200
   VCID: 5BB5FEB59A60F599DC-800E

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect.        Labels: 4F0-910-279.lbl
   Part No SW: 4F0 910 279 E    HW: 4F0 907 279 B
   Component: ILM Fahrer      H15 0190  
   Revision: 00000000    Serial number: 4F0907279     
   Coding: 0010103
   Shop #: WSC 02335 785 00200
   VCID: 2B556E758A4045196C-807E

   Subsystem 1 - Part No: 4F1 910 113   Labels: 1KX-955-119.CLB
   Component: Wischer AudiC6  H05 0150  
   Coding: 00062736
   Shop #: WSC 02335  

   Subsystem 2 - Part No: 4E0 910 557   Labels: 8K0-955-559.CLB
   Component: REGENLICHTSENSORH10 0050  
   Coding: 00141886
   Shop #: WSC 02335  

No fault code found.

-------------------------------------------------------------------------------
Address 0E: Media Player 1        Labels: 4E0-910-111.lbl
   Part No SW: 4E0 910 111 E    HW: 4E0 035 111 A
   Component: CD-Changer      H44 0430  
   Revision: 00000000    Serial number: AUZ5ZBE7260216
   Shop #: WSC 00000 000 00000
   VCID: 1B35BEB5DAE0B5991C-804E

No fault code found.

-------------------------------------------------------------------------------
Address 0F: Digital Radio        Labels: 4E0-910-593-XM.lbl
   Part No SW: 4E0 910 593 A    HW: 4E0 035 593 A
   Component: SDAR   
   Revision: 0000000    Serial number: AUZ4Z7D80
   Shop #: WSC 00000 000 00000
   VCID: 2541984DECA47369BA-8070

1 Fault Found:
02635 - Tuner Not Enabled/Activated 
            000 -  - 
             Freeze Frame:
                    Fault Status: 01100000
                    Fault Priority: 7
                    Fault Frequency: 1
                    Reset counter: 206
                    Mileage: 138853 km
                    Time Indication: 0
                    Date: 2016.04.12
                    Time: 07:54:51


-------------------------------------------------------------------------------
Address 15: Airbags        Labels: 4F0-910-655-8R.clb
   Part No SW: 4F0 910 655 F    HW: 4F0 959 655 A
   Component: 66 AIRBAG AUDI8RH29 0270  
   Revision: 12H29000    Serial number: 00359D0A6EJ-  
   Coding: 0013878
   Shop #: WSC 02325 785 00200
   VCID: 2A5B6B7185BA5C1197-807E

   Subsystem 1 - Part No: 4F0 910 339 A
   Component: BF-Gewichtsens. H02 0050

   Subsystem 2 - Serial number: 6332CSME0C5F6564E

   Subsystem 3 - Serial number: 6342CSME0D025C5A9

   Subsystem 4 - Serial number: 6352QSME06183D2FP

   Subsystem 5 - Serial number: 6362QSME054D310DH

   Subsystem 6 - Serial number: 63734SME055A4163Z

   Subsystem 7 - Serial number: 63834SME066E13492

1 Fault Found:
00532 - Supply Voltage B+ 
            002 - Lower Limit Exceeded - Intermittent

-------------------------------------------------------------------------------
Address 16: Steering wheel        Labels: 4F0-910-549.lbl
   Part No SW: 4F0 910 549     HW: 4F0 953 549 A
   Component: Lenksäulenmodul H07 0230  
   Revision: 00H07000    Serial number: 90054052950646
   Coding: 0002021
   Shop #: WSC 02323 785 00200
   VCID: 66C3DF415122B87173-8032

   Subsystem 1 - Part No: XXXXXXXXXXX 
   Component: Lenkradmodul    H07 0080

1 Fault Found:
00446 - Function Limitation due to Under-Voltage 
            002 - Lower Limit Exceeded
             Freeze Frame:
                    Fault Status: 01100010
                    Fault Priority: 6
                    Fault Frequency: 3
                    Reset counter: 255
                    Mileage: 137888 km
                    Time Indication: 0
                    Date: 2016.02.29
                    Time: 15:00:44


-------------------------------------------------------------------------------
Address 17: Instruments        Labels: 4F0-910-xxx-17.lbl
   Part No SW: 4F0 910 900 A    HW: 4F0 920 950 M
   Component: KOMBIINSTR. M73 H11 0630  
   Revision: 00100000    Serial number: 4R812DVA5     
   Coding: 0019263
   Shop #: WSC 00001 067 57207
   VCID: 1E33B7A1C9F2A0B1FB-804A

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway        Labels: 4F0-910-468.clb
   Part No SW: 4F0 910 468 A    HW: 4F0 907 468 D
   Component: Gateway         H11 0070  
   Revision: 11          Serial number: 1300805A2681F1
   Coding: 6CFE53C51B1904
   Shop #: WSC 03164 444 52200
   VCID: 275D924596A8617988-8072

No fault code found.

-------------------------------------------------------------------------------
Address 42: Door Elect, Driver        Labels: 4F0-910-793-42.lbl
   Part No SW: 4F0 910 793 E    HW: 4F0 959 793 E
   Component: TSG FA          H12 0080  
   Revision: 00000000    Serial number: 	
   Coding: 0035435
   Shop #: WSC 02327 785 00200
   VCID: 2C576D698F4E422165-8078

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv.        Labels: 4F0-910-289.lbl
   Part No SW: 4F0 910 289 G    HW: 4F0 907 289 G
   Component: Komfortgeraet   H22 0170  
   Revision: 01700022    Serial number: 01008313330000
   Coding: 4618301
   Shop #: WSC 02335 785 00200
   VCID: 2E536761B95230314B-807A

   Subsystem 1 - Part No: 1K0 951 605 C
   Component: LIN BACKUP HORN H03 1301

No fault code found.

-------------------------------------------------------------------------------
Address 47: Sound System        Labels: 4F0-910-223-AS.lbl
   Part No SW: 4F0 910 223 B    HW: 4F0 035 223 
   Component: Amp.-ASK        H09 0270  
   Revision: 21S00001    Serial number: 02610050167360
   Coding: 0000006
   Shop #: WSC 02335 785 00200
   VCID: 1D31B0ADC4F4BBA9E2-8048

No fault code found.

-------------------------------------------------------------------------------
Address 4F: Centr. Electr. II        Labels: 4F0-910-280.lbl
   Part No SW: 4F0 910 280     HW: 4F0 907 280 B
   Component: ILM Beifahrer   H10 0080  
   Revision:             Serial number: 00000000009583
   Coding: 0002114
   Shop #: WSC 02323 785 00200
   VCID: 5EB3F7A18972E0B1BB-800A

No fault code found.

-------------------------------------------------------------------------------
Address 52: Door Elect, Pass.        Labels: 4F0-910-793-52.lbl
   Part No SW: 4F0 910 793 E    HW: 4F0 959 792 E
   Component: TSG BF          H12 0080  
   Revision: 00000000    Serial number: ™‚
   Coding: 0035435
   Shop #: WSC 02327 785 00200
   VCID: 2C576D698F4E422165-8078

No fault code found.

-------------------------------------------------------------------------------
Address 53: Parking Brake        Labels: 4F0-910-801.clb
   Part No SW: 4F0 910 801     HW: 4F0 907 801 
   Component: EPB  C63C0030   H03 0030  
   Revision: C63C0030    
   Coding: 0005022
   Shop #: WSC 02334 785 00200
   VCID: 5DB1F0AD8474FBA9A2-8008

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio        Labels: 4E0-910-541.lbl
   Part No SW: 4E0 910 541 F    HW: 4F0 035 541 B
   Component: TUNER EU/US/RDW H42 0480  
   Revision: 00000000    Serial number: 394J%057629762
   Coding: 0000002
   Shop #: WSC 02323 785 00200
   VCID: 23458655E2908D59D4-8076

No fault code found.

-------------------------------------------------------------------------------
Address 61: Battery Regul.        Labels: 4F0-910-181.lbl
   Part No SW: 4F0 910 181 E    HW: 4F0 915 181 A
   Component: J0644 BEM       H12 0590  
   Revision: 00000000    Serial number: 00000000141655
   Shop #: WSC 03109 444 64620
   VCID: 23458655E2908D59D4-8076

   Subsystem 1 - Part No: 4F0 915 105 C
   Component: von VA0  2510230170       
   Coding: 344630393135313035432056413032353130323330313730
   Shop #: WSC 00000 384 00290

5 Faults Found:
02272 - Quiescent Current Stage 1 
            000 -  -  - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 7
                    Fault Frequency: 19
                    Reset counter: 255
                    Mileage: 137888 km
                    Time Indication: 0
                    Date: 2016.02.29
                    Time: 12:07:03

02273 - Quiescent Current Stage 2 
            000 -  -  - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 7
                    Fault Frequency: 19
                    Reset counter: 255
                    Mileage: 137888 km
                    Time Indication: 0
                    Date: 2016.02.29
                    Time: 12:07:03

02276 - Quiescent Current Stage 5 
            000 -  -  - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 7
                    Fault Frequency: 10
                    Reset counter: 255
                    Mileage: 137888 km
                    Time Indication: 0
                    Date: 2016.02.29
                    Time: 12:13:39

02274 - Quiescent Current Stage 3 
            000 -  -  - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 7
                    Fault Frequency: 10
                    Reset counter: 255
                    Mileage: 137888 km
                    Time Indication: 0
                    Date: 2016.02.29
                    Time: 12:13:39

02277 - Quiescent Current Stage 6 
            000 -  -  - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 7
                    Fault Frequency: 6
                    Reset counter: 255
                    Mileage: 149524 km
                    Time Indication: 0
                    Date: 2017.05.07
                    Time: 01:39:19


-------------------------------------------------------------------------------
Address 62: Door, Rear Left        Labels: 4F0-910-795.lbl
   Part No SW: 4F0 910 795 E    HW: 4F0 959 795 E
   Component: TSG HL          H21 0050  
   Coding: 0035370
   Shop #: WSC 02327 785 00200
   VCID: 2E536761B95230314B-807A

No fault code found.

-------------------------------------------------------------------------------
Address 65: Tire Pressure        Labels: 4F0-910-273-BA.lbl
   Part No SW: 4F0 910 273 B    HW: 4F0 907 273 A
   Component: Reifendruck 3   H05 0100  
   Revision: 00050100    Serial number: 00000900013371
   Coding: 0062221
   Shop #: WSC 02334 785 00200
   VCID: 224B8351FD8A8451DF-8076

No fault code found.

-------------------------------------------------------------------------------
Address 72: Door, Rear Right        Labels: 4F0-910-795.lbl
   Part No SW: 4F0 910 795 E    HW: 4F0 959 794 E
   Component: TSG HR          H21 0050  
   Coding: 0035370
   Shop #: WSC 02327 785 00200
   VCID: 2E536761B95230314B-807A

No fault code found.

-------------------------------------------------------------------------------
Address 77: Telephone        Labels: 4E0-910-336.lbl
   Part No SW: 4F0 910 336 B    HW: 4E0 862 335 
   Component: Handyvorb2      H11 0440  
   Revision: 00000000    Serial number: 00000007521483
   Coding: 0010900
   Shop #: WSC 02335 785 00200
   VCID: 224B8351FD8A8451DF-8076

No fault code found.

End-------------------------(Elapsed Time: 02:40)--------------------------