2011 A5 Coupe AC not working - G395 Implausible Signal

ppopovec · Jul 30, 2020

Please help .. old topic but cannot find my answer.
I am new to and just bought VSDS but not new to fixing Audi/VW ... started with a couple of my daughters VW New Bugs and have worked on many since. I am a hobby gear head that searches Craigslist for blown timing belts or head gasket problems, fix, and then drive or sell. I recently got a nice black on black 2011 A5 Coupe that had a radiator leak and was driven hot and blew head gasket. Car sat for several months. Got all that fixed and it runs great. To do job, took entire front end off, but left AC condenser aside to not lose charge. Now the AC does not work. Checked with previous owner and he said it worked fine when he sold it to me. Autoscan below. Refrigerant charge is good check with gauges. Direct 12v to compressor leads and AC works. I know this is elsewhere on forum, but have tried a new aftermarket G395 sensor with no change. Tried an OEM G395, no change. Connector is good and wires are traced OK to the inside of the fenderwell. I do not have and cannot find the wiring diagram to check which wires to verify continuity to J519. Any help or suggestions truly appreciated.

Other things I have checked
- from G395 plug unplugged ... voltage from brown wire to battery positive = 14.2v
- from G395 plug unplugged ... voltage from brown wire to Grey/Red wire = 14.1v.
- from G395 plug unplugged ... voltage from brown wire to Yellow/Grey wire = 10.1v

- from G395 plugged in (stripped wire near removed headlight) ... voltage from brown wire to Grey/Red wire = 14.1v.
- from G395 plugged in (stripped wire near removed headlight) ... voltage from brown wire to Yellow/Grey wire = 10.1v

Code:

Wednesday,29,July,2020,18:58:45:53865
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x86
VCDS Version: 20.4.1.0  HEX-V2 CB: 0.4526.4
Data version: 20200331 DS317.0
www.Ross-Tech.com


VIN: WAULFAFR1BA077395   License Plate: 


Gateway Installation List:  8T0 907 468 AH

01-Engine -- Status: OK 0000
02-Auto Trans -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
04-Steering Angle -- Status: OK 0000
05-Acc/Start Auth. -- Status: OK 0000
06-Seat Mem. Pass -- Status: OK 0000
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: Malfunction 0010
10-Park/Steer Assist -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: OK 0000
19-CAN Gateway -- Status: OK 0000
36-Seat Mem. Drvr -- Status: Malfunction 0010
42-Door Elect, Driver -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
47-Sound System -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
53-Parking Brake -- Status: OK 0000
55-Headlight Range -- Status: Malfunction 0010
56-Radio -- Status: OK 0000
5F-Information Electr. -- Status: OK 0000
6C-Back-up Cam. -- Status: OK 0000
 
Wednesday,29,July,2020,19:03:38:53865
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x86
VCDS Version: 20.4.1.0  HEX-V2 CB: 0.4526.4
Data version: 20200331 DS317.0
www.Ross-Tech.com


VIN: WAULFAFR1BA077395   License Plate: 


Chassis Type: FR-AU48 (8T0)
Scan: 01 02 03 05 06 08 09 10 15 16 17 19 36 42 46 47 52 53 55 56
          5F 6C

VIN: WAULFAFR1BA077395   Mileage: 187150km-116289miles

01-Engine -- Status: OK 0000
02-Auto Trans -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
04-Steering Angle -- Status: OK 0000
05-Acc/Start Auth. -- Status: OK 0000
06-Seat Mem. Pass -- Status: OK 0000
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: Malfunction 0010
10-Park/Steer Assist -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: OK 0000
19-CAN Gateway -- Status: OK 0000
36-Seat Mem. Drvr -- Status: Malfunction 0010
42-Door Elect, Driver -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
47-Sound System -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
53-Parking Brake -- Status: OK 0000
55-Headlight Range -- Status: Malfunction 0010
56-Radio -- Status: OK 0000
5F-Information Electr. -- Status: OK 0000
6C-Back-up Cam. -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine (0-----CAEB)       Labels:| 06H-907-115-CAB.clb
   Part No SW: 8K2 907 115 AG    HW: 8K2 907 115 D
   Component: 2.0l R4/4V TF H20 0002  
   Revision: E1H20---    
   Coding: 0114010A290F0160
   Shop #: WSC 08166 444 101336
   ASAM Dataset: EV_ECM20TFS0118K2907115AG 001002
   ROD: EV_ECM20TFS0118K2907115AG.rod
   VCID: 74B1D9296E36093B473-8020

No fault code found.
Readiness: 1110 0101

-------------------------------------------------------------------------------
Address 02: Auto Trans (J217)       Labels:| 0BK-927-156.clb
   Part No SW: 8K0 927 158 S    HW: 0BK 927 156 R
   Component: 0BK 20TFSIUSA H08 1005  
   Revision: --H08---    
   Coding: 000002
   Shop #: WSC 00000 000 00000
   ASAM Dataset: EV_TCMAL551211 002018
   ROD: EV_TCMAL551211_002_AU48.rod
   VCID: 46D553E1482ACBAB297-8012

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104)       Labels:. 8K0-907-379-V1.clb
   Part No SW: 8K0 907 379 BJ    HW: 8K0 907 379 BJ
   Component: ESP8 quattro  H04 0060  
   Revision: --------    Serial number: --------------
   Coding: 1D0D18
   Shop #: WSC 06324 000 00000
   VCID: 025D8FF12402378B45F-8056

No fault code found.

-------------------------------------------------------------------------------
Address 05: Acc/Start Auth. (J393)       Labels:. 8K0-907-064-05.clb
   Part No SW: 8K0 907 064 CF    HW: 8K0 907 064 CF
   Component: BCM2 2.0      H05 0435  
   Revision: 00002001    
   Coding: 090000
   Shop #: WSC 06325 000 00000
   VCID: 76B5E32178CA1B2B797-8022

   Subsystem 1 - Part No SW: 8T0 959 754 A    HW: 8T0 959 754 A
   Component: FBSAUDIB8 IDG  H60 0072 
   Serial number: 0811000046484010    

   Subsystem 2 - Part No SW: 8K0 905 852 D    HW: 8K0 905 852 D
   Component: J764 ELV MLB  H37 0042 
   Serial number: 2311000059798014    

No fault code found.

-------------------------------------------------------------------------------
Address 06: Seat Mem. Pass (J521)       Labels:. 8T0-959-760.clb
   Part No SW: 8T0 959 760 C    HW: 8T0 959 760 C
   Component: MEM-BFS       H10 0074  
   Revision: AA000000    Serial number: 00000006083969
   Coding: 08017025002400001000
   Shop #: WSC 06325 000 00000
   VCID: 43D34AF57B98FE830E9-8016

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J255)       Labels:. 8Tx-820-043-3Z.clb
   Part No SW: 8T1 820 043 AQ    HW: 8T1 820 043 AQ
   Component: KLIMA 3 ZONEN H08 0180  
   Revision: C1000000    Serial number: 01150420110116
   Coding: 64122000
   Shop #: WSC 06325 000 00000
   VCID: 005985F92A0E259B53B-8054

2 Faults Found:
00457 - Central Electronics Control Module / BCM (J519) 
            013 - Check DTC Memory
             Freeze Frame:
                    Fault Status: 01101101
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:04

00256 - A/C Pressure/Temperature Sensor (G395) 
            008 - Implausible Signal
             Freeze Frame:
                    Fault Status: 01101000
                    Fault Priority: 7
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:05

             Freeze Frame:
                    Temperature: 28.0°C


-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519)       Labels:. 8K0-907-063.clb
   Part No SW: 8K0 907 063 P    HW: 8K0 907 063 P
   Component: BCM1 1.0      H30 0392  
   Revision: 10030001    Serial number: 00000000864924
   Coding: 26001091063CAF010000080300003D3D0F1C528802010161000000
   Shop #: WSC 06325 000 00000
   VCID: 3C2131090666817B4F3-8068

   Subsystem 1 - Part No SW: 8T1 955 119 D    HW: 8J1 955 119   Labels: 1KX-955-119.CLB
   Component: WWS 310311  H15 0070 
   Serial number: SWF11030315846      
   Coding: 00FD11

   Subsystem 2 - Part No SW: 8K0 955 559     HW: 8K0 955 559   Labels: 8K0-955-559.CLB
   Component: RLS  H04 0003 
   Serial number: 11381392            
   Coding: 02532C

   Subsystem 3 - Part No SW: 8K0 941 531 BA    HW: 8K0 941 531 BA
   Component: E1 - LDS  H03 0031 
   Serial number: 00000000002903110571

   Subsystem 4 - Part No SW: 8K0 907 410 C    HW: 8K0 907 410 C
   Component: HOMELINK  H01 0010 

3 Faults Found:
02895 - Supply Voltage for LED Module for DRL and Parking Light; Left 
            012 - Electrical Fault in Circuit
             Freeze Frame:
                    Fault Status: 01101100
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:00

02897 - Supply Voltage for LED Module for DRL and Parking Light; Right 
            012 - Electrical Fault in Circuit
             Freeze Frame:
                    Fault Status: 01101100
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:00

00256 - A/C Pressure/Temperature Sensor (G395) 
            004 - No Signal/Communication
             Freeze Frame:
                    Fault Status: 01100100
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:00


-------------------------------------------------------------------------------
Address 10: Park/Steer Assist (J446)       Labels:. 8K0-919-475.clb
   Part No SW: 8K0 919 475 T    HW: 8P0 919 475 M
   Component: PARKHILFE 4K  H01 0080  
   Revision: 11001001    Serial number: 36891109842590
   Coding: 200101
   Shop #: WSC 06325 000 00000
   VCID: 4ACD67D15CB22FCBCDF-801E

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags (J234)       Labels:| 8K0-959-655.clb
   Part No SW: 8K0 959 655 K    HW: 8K0 959 655 K
   Component: AirbagVW-AU10 H45 0610  
   Serial number: 003GLD904KJJ  
   Coding: 303338334330303030304A55304C38543053
   Shop #: WSC 28955 002 1048576
   ASAM Dataset: EV_AirbaECUVWAUDI010 003010
   ROD: EV_AirbaECUVWAUDI010_003_AU48.rod
   VCID: 45D754ED752CC0B320D-8010

   Seat occupied recognition: 
   Subsystem 1 - Part No SW: 8K0 959 339 A    HW: 8K0 959 339 A
   Component: BF-Gewichtss.  H02 0060 
   Serial number: 5810000R11000043S1

   Crash sensor for side airbag: driver side: 
   Serial number: 6334MSME4C2A4B62O

   Crash sensor for side airbag: front passenger side: 
   Serial number: 6344MSME5E321A4CP

   Crash sensor for side airbag: rear: driver side: 
   Serial number: 6352QSME69424460C

   Crash sensor for side airbag: rear: passenger side: 
   Serial number: 6362QSME190213565

   Crash sensor for front airbag: driver side: 
   Serial number: 63732SME2B1E1662%

   Crash sensor for front airbag: front passenger side: 
   Serial number: 63832SME034C3E5EC

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel (J527)       Labels:. 8K0-953-568.clb
   Part No SW: 8R0 953 568 K    HW: 8R0 953 568 K
   Component: Lenks.Modul   H07 0156  
   Revision: 00000000    Serial number: 20110414000178
   Coding: 000016
   Shop #: WSC 06325 000 00000
   VCID: 49CF58DD59B424D3C45-801C

   Component: E221 - MFL  H02 0010 

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285)       Labels:. 8T0-920-xxx-17.clb
   Part No SW: 8T0 920 983 A    HW: 8T0 920 983 A
   Component: KOMBIINSTR.   H43 0261  
   Revision: 00100000    Serial number: NVB423L4H     
   Coding: 8B1701000300D705020000
   Shop #: WSC 43371 001 1048576
   VCID: 3C2131090666817B4F3-8068

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway (J533)       Labels:. 8T0-907-468.clb
   Part No SW: 8T0 907 468 AH    HW: 8T0 907 468 K
   Component: GW-BEM 4CAN-M H09 0120  
   Revision: EC101057    Serial number: 5700E127130325
   Coding: 00C303
   Shop #: WSC 43371 001 1048576
   VCID: 074B9EE50F2012A3121-8052

   Subsystem 1 - Part No SW: 8K0 915 181 E    HW: 8K0 915 181 E
   Component: J367-BDM  H07 0170 
   Serial number: 11014077310311      

No fault code found.

-------------------------------------------------------------------------------
Address 36: Seat Mem. Drvr (J136)       Labels:. 8T0-959-760.clb
   Part No SW: 8T0 959 760 C    HW: 8T0 959 760 C
   Component: MEM-FS        H10 0074  
   Revision: AA000000    Serial number: 00000006083129
   Coding: 08017025002400001000
   Shop #: WSC 50508 001 1048576
   VCID: 43D34AF57B98FE830E9-8016

3 Faults Found:
03338 - Force Limit for Fore/Aft Seat Adjustment: Forwards 
            005 - No or Incorrect Basic Setting / Adaptation
             Freeze Frame:
                    Fault Status: 01100101
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:04

02095 - Component Protection Active 
            000 - -
             Freeze Frame:
                    Fault Status: 01100000
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:04

03334 - Motor for Head Rest Adjustment 
            005 - No or Incorrect Basic Setting / Adaptation
             Freeze Frame:
                    Fault Status: 01100101
                    Fault Priority: 4
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:04


-------------------------------------------------------------------------------
Address 42: Door Elect, Driver (J386)       Labels:. 8K0-959-793.clb
   Part No SW: 8T0 959 793 M    HW: 8T0 959 793 D
   Component: TSG FA        H08 1501  
   Revision: --------    Serial number: --------------
   Coding: 011C03224000120102
   Shop #: WSC 06325 000 00000
   VCID: 53F37AB58BF86E03BE9-8006

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv. (J393)       Labels:. 8K0-907-064-46.clb
   Part No SW: 8K0 907 064 CF    HW: 8K0 907 064 CF
   Component: BCM2 2.0      H05 0435  
   Revision: 00002001    Serial number: 0145616613    
   Coding: 0106029A00FA440480B0003200000000
   Shop #: WSC 06325 000 00000
   VCID: 76B5E32178CA1B2B797-8022

   Subsystem 1 - Part No SW: 8K0 959 719 B    HW: 8K0 959 719 
   Component: GTO BF  H01 0070 
   Serial number: 00000000000000381529

   Subsystem 2 - Part No: 1K0 951 605 C
   Component: LIN BACKUP HO  H05 1501 

   Subsystem 3 - Part No SW: 8R0 959 591 A    HW: 8R0 959 591 
   Component: J245EE20SKB13  H02 0220 
   Serial number: 0123456789ABCDEFGHIJ

No fault code found.

-------------------------------------------------------------------------------
Address 47: Sound System (J525)       Labels:. 8T0-035-223-BOM.clb
   Part No SW: 8T0 035 223 AN    HW: 8T0 035 223 AK
   Component: DSP Prem      H10 0190  
   Revision: 00010001    Serial number: 34804005168801
   VCID: 7AADF7114CD27F4B1DF-802E

No fault code found.

-------------------------------------------------------------------------------
Address 52: Door Elect, Pass. (J387)       Labels:. 8K0-959-792.clb
   Part No SW: 8T0 959 792 M    HW: 8T0 959 792 D
   Component: TSG BF        H08 1501  
   Revision: --------    Serial number: --------------
   Coding: 011C03224000120102
   Shop #: WSC 06325 000 00000
   VCID: 52FD7FB1B4E2670BB5F-8006

No fault code found.

-------------------------------------------------------------------------------
Address 53: Parking Brake (J540)       Labels: 8K0-907-801-V1.clb
   Part No SW: 8K0 907 801 H    HW: 8K0 907 801 H
   Component: EPB Audi B8   H09 0100  
   Revision: 00000003    Serial number: 00000000919351
   Shop #: WSC 00000 000 00000
   VCID: 343119292E36493B873-8060

No fault code found.

-------------------------------------------------------------------------------
Address 55: Headlight Range        Labels: 8K0-907-357.clb
   Part No: 8K5 907 357 B
   Component: Dynamische LWR  H02 0010  
   Revision: 00000001    Serial number:               
   Coding: 0000002
   Shop #: WSC 06325 000 00000
   VCID: 392F281D0554B453545-806C

2 Faults Found:
01535 - Control Circuit for Right Headlight Range Adjusting Motor (V49) 
            010 - Open or Short to Plus - MIL ON
             Freeze Frame:
                    Fault Status: 11101010
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:04

01534 - Control Circuit for Left Headlight Range Adjusting Motor (V48) 
            010 - Open or Short to Plus - MIL ON
             Freeze Frame:
                    Fault Status: 11101010
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.29
                    Time: 18:00:04


-------------------------------------------------------------------------------
Address 56: Radio (R)       Labels: Redir Fail!
   Part No SW: 4G0 035 082     HW: 4G0 035 082 
   Component: Radio U SIRIU H51 0052  
   Revision: AB001007    Serial number: 471D+0B7573539
   Coding: 020007010000000001
   Shop #: WSC 06325 000 00000
   VCID: 5DE79C8DFD3CA87318D-8008

No fault code found.

-------------------------------------------------------------------------------
Address 5F: Information Electr. (J794)       Labels:. 4E0-035-6xx-5F.clb
   Part No SW: 8T1 035 664 C    HW: 8T1 035 664 B
   Component: H-BN-NA       H51 0116  
   Revision: --------    Serial number: 490DU0B7614207
   Coding: 010200020006A1EF41000B0E000000030000
   Shop #: WSC 06325 000 00000
   VCID: 38292D19325EAD5BABB-806C

   Subsystem 1 - Part No: 8R0 060 884 P
   Component: NAR 2010  0407 

   Subsystem 2 - Part No SW: 8F0 919 604     HW: 8F0 919 604 
   Component: DU7 High  H43 0084 
   Serial number: 9466CU0B0557710     

   Subsystem 3 - Part No SW: 8T0 919 609 F    HW: 8T0 919 609 F
   Component: E0380 Bedient  H08 0100 
   Serial number: 00000000800169      

   Subsystem 4 - Part No: 8R0 060 961 
   Component: CD-Database  1886 

No fault code found.

-------------------------------------------------------------------------------
Address 6C: Back-up Cam.        Labels: 8T0-907-441.clb
   Part No SW: 8T0 907 441 C    HW: 4L0 907 441 B
   Component: J772__Rearview      0040  
   Revision: --H05---    Serial number: 525PA8-J1191IL
   Coding: 1000008
   Shop #: WSC 06325 000 00000
   VCID: 38292D193E5EAD5BABB-806C

No fault code found.

End----------(Elapsed Time: 01:43, VBatt start/end: 14.1V/14.2V)-----------

Jef · Jul 30, 2020

First post with an Auto-Scan... you shall live. :thumbs:

Look behind the Audi badge on the grill, you should find a small black box there with a T4a connector, but 3 wires, unplug it. T4a/2 should be another ge/gr (yellow/grey) wire like you found at the G395 T3t/2.

Now ohm test the wire from T4a/2 to T3t/2, said ge/gr wire and verify it is a dead short. If so, plug the G395 back up, but do not plug up that black box behind the Audi badge in the grill. Now see if you can clear out fault codes for the G395 no signal/comm.

Note, that black box is the garage door opener, it communicates over the same LIN Bus wire (ge/gr) wire as the G395.

ppopovec · Jul 30, 2020

Thanks for the quick reply ... apologies for the typo in VCDS above
I have unplugged the garage door opener and ohm tested the wire from T4a/2 to T3t/2, said ge/gr wire and verify it is a dead short ... 0 ohms with meter ringing ... dead short.
I then cleared the HVAC codes, exited the module, and then went back into module and codes still there.
When I go to measuring blocks, "Error" appears in the value for G395.

Code:

Thursday,30,July,2020,16:57:37:53865
VCDS Version: Release 20.4.1 Running on Windows 10 x86
www.Ross-Tech.com

                Address 08: Auto HVAC       Labels: 8Tx-820-043-3Z.clb
Control Module Part Number: 8T1 820 043 AQ    HW: 8T1 820 043 AQ
  Component and/or Version: KLIMA 3 ZONEN H08 0180
           Software Coding: 64122000
            Work Shop Code: WSC 06325 000 00000
                      VCID: 005985F92A0E259B53B-8054
2 Faults Found:

00256 - A/C Pressure/Temperature Sensor (G395) 
            008 - Implausible Signal
             Freeze Frame:
                    Fault Status: 01101000
                    Fault Priority: 7
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.30
                    Time: 15:57:32

             Freeze Frame:
                    Temperature: 25.0°C

00457 - Central Electronics Control Module / BCM (J519) 
            013 - Check DTC Memory
             Freeze Frame:
                    Fault Status: 01101101
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 234
                    Mileage: 187154 km
                    Time Indication: 0
                    Date: 2020.07.30
                    Time: 15:57:32

Jef · Jul 30, 2020

Well.. hmmmm... at face value it would seem you have a bad G395 sensor. Just for giggles, lets make sure the power/ground at the G395 can carry load. Unplug the G395 and wire up a brake light bulb to T3t/1 and T3t/3 and verify it powers it up.

ppopovec · Jul 30, 2020

Thanks again for the quick reply ...
Wired up the brake light bulb as you suggested. Burns very bright when G395 unplugged and wired to brake light.
(Not sure if image came through)

ppopovec · Jul 30, 2020

Also to note ... when I remove the G395 I get the little spurt of refrigerant. I connected my gauges at the G395 connection and have ~100 psig (about 80 degF here today) so about right.

Jef · Jul 30, 2020

We can't see photos directly off your personal computer Phil.

This thread shows how to post photos here:

https://forums.ross-tech.com/showthread.php?95-How-To-Post-Pictures

I would suggest using imgur.com.

Each time you remove the G395, it will vent a small amount. Look at the sensor, it has a post inside of it that will push down on a ball seal. As you remove it, while the ball seal closes off the system, there is that tiny amount of charge within the G395 itself and once you get it past an O-ring, it does that spurt.

As it stands, all signs point to a bad sensor. You've got power and ground to the sensor, they can carry load. The data wire seem fine in that it is a direct short to from the G395 to the garage door opener's data line and said garage door opener was talking as well. And we left the garage door opener unplugged and that didn't help so the garage door opener isn't screwing up the data line. Now having said that last statement, the data line, a LIN Bus #2, there can be other items on it.

You might have an Air Quality Sensor (G238) on the LIN Bus, located at the base of the windshield at the vent box intake... if you see such a sensor there, unplug it and then see if the G395 can talk. Also, be 100% sure the currently installed G395 is the OE replacement from the Audi dealer, anything thing else is crap and not to be trusted.

ppopovec · Jul 31, 2020

Thanks again for the quick feedback and help.
I unplugged the air quality sensor and it made no difference.
I bought the OEM G395 online and have now ordered one from the dealer ... arriving tomorrow.
Hope it works ... as this seems to have us baffled.
As a note ... when i press the "A/C" button on the climate control it stays lit red ... not sure that tells us anything.
I will update tomorrow when I get the dealer sensor.

ppopovec · Aug 1, 2020

Got the dealer sensor this morning and you guessed it ... it worked fine ... AC is now working
So much for internet "OEM" sensors.

Also to note ... I called the Audi Dealer and they did not have it but wanted $138 for it ... I called the VW dealer around the corner from the Audi dealer and they only wanted $90 for it ... same exact part number ... I got it from the VW dealer.

Thanks for the help troubleshooting and the quick replys ... very much appreciated.
I hope this helps someone else out there.

Jef · Aug 1, 2020

ppopovec said:
Got the dealer sensor this morning and you guessed it ... it worked fine ... AC is now working
So much for internet "OEM" sensors.

Several times a day on phones with repair shops I'm telling them, anything with an electrical connector on it, buy it from the dealer. Oh the number of times I've heard shops with broken car argue "... it came in a Bosch box....". :facepalm:

Uwe · Aug 1, 2020

Jef said:
"... it came in a Bosch box....".

20 - 30 years ago, that was generally OK.

Now, not so much.

-Uwe-

rusty75 · Jan 5, 2022

ppopovec said:
I hope this helps someone else out there.

YES it does!
As it turns out, I have the exact same two errors showing in my auto scan results,
so I am definitely going to go this route as well.
Many thanks!

rusty75 · Oct 9, 2023

how seriously funny, I realized it was me who had replied over a year ago, that is hilarious

(this is my hobby car and it has been sitting idle for a long time)

2011 A5 Coupe AC not working - G395 Implausible Signal

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