A8 D3 Temperature Gauge - which ECU / measurement block please? ...

[JulianHicks]

The temperature gauge on my MY2005 A8 D3 has started 'wandering' recently. I'd like to identify whether it's the thermostat or a sensor.

Obviously the panel ECU gets the temperature, but which ECU is the cooling circuit temperature sensor connected to? [The engine is a V6 3.0 TDI - "ASB"].

As a starting point, I plan to monitor the appropriate measurement block on a long journey with VCDS saving to disk. Any clues which block I should be looking at?

Thanks - Julian

Autoscan added below retroactively

Wednesday,05,October,2016,18:49:05:53697
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x86
VCDS Version: 16.8.2.3
Data version: 20160926 DS261.0
www.Ross-Tech.com


VIN: WAUZZZ4E35N011492   License Plate: 


Chassis Type: 4E (4E0)
Scan: 01 02 03 05 06 07 08 09 0E 15 16 17 18 19 1D 1E 25 34 36 37
          38 42 46 47 4F 52 53 56 57 61 62 72 76 77

VIN: WAUZZZ4E35N011492   Mileage: 360110km-223761miles

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
06-Seat Mem. Pass        -- Status: OK 0000
07-Control Head          -- Status: OK 0000
08-Auto HVAC             -- Status: OK 0000
09-Cent. Elect.          -- Status: OK 0000
0E-Media Player 1        -- Status: OK 0000
15-Airbags               -- Status: OK 0000
16-Steering wheel        -- Status: OK 0000
17-Instruments           -- Status: OK 0000
18-Aux. Heat             -- Status: Malfunction 0010
19-CAN Gateway           -- Status: OK 0000
1D-Driver Ident.         -- Status: OK 0000
1E-Media Player 2        -- Status: OK 0000
25-Immobilizer           -- Status: OK 0000
34-Level Control         -- Status: OK 0000
36-Seat Mem. Drvr        -- Status: OK 0000
37-Navigation            -- Status: OK 0000
38-Roof Electronics      -- 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
57-TV Tuner              -- Status: OK 0000
61-Battery Regul.        -- Status: OK 0000
62-Door, Rear Left       -- Status: OK 0000
72-Door, Rear Right      -- Status: OK 0000
76-Park Assist           -- Status: OK 0000
77-Telephone             -- Status: OK 0000
 
-------------------------------------------------------------------------------
Address 01: Engine        Labels: 059-907-401-ASB.clb
   Part No SW: 4E0 910 401 J    HW: 4E0 907 401 B
   Component: 3.0L V6TDI  G000AG  0020  
   Revision: --H01---    Serial number: AUX3Z0D9353518
   Coding: 0011973
   Shop #: WSC 02313 785 00200
   VCID: 224B8DE9FD1E305282-8076

3 Faults Found:
17983 - Right Engine Mount Solenoid Valve (N145) 
            P1575 - 001 - Short to Plus
             Freeze Frame:
                    RPM: 756 /min
                    Torque: 39.0 Nm
                    Speed: 0.0 km/h
                    Voltage: 13.07 V
                    Bin. Bits:        0
                    Bin. Bits:        0
                    Bin. Bits:        0
                    Temperature: 64.8°C

18276 - Transmission Mount Valve 1 (N262) 
            P1868 - 001 - Short to Plus
             Freeze Frame:
                    RPM: 756 /min
                    Torque: 39.0 Nm
                    Speed: 0.0 km/h
                    Duty Cycle: 1.0 %
                    Voltage: 13.07 V
                    Bin. Bits: 00101100
                    Torque: 249.6 Nm
                    Temperature: 64.8°C

18281 - Transmission Mount Valve 2 (N263) 
            P1873 - 001 - Open Circuit - Intermittent
             Freeze Frame:
                    RPM: 756 /min
                    Torque: 74.1 Nm
                    Speed: 0.0 km/h
                    Voltage: 13.45 V
                    Bin. Bits:        0
                    Bin. Bits:        0
                    Bin. Bits:        0
                    Temperature: 64.8°C

Readiness: 0 0 0 0 0 

-------------------------------------------------------------------------------
Address 02: Auto Trans        Labels: 09L-927-760.lbl
   Part No SW: 4E0 910 156 F    HW: 09L 927 156 
   Component: AG6 09L 3.0lTDI RdW 0070  
   Revision: --H01---    Serial number:        0070658
   Coding: 0000001
   Shop #: WSC 02313 785 00200
   VCID: 254196F5EC30C76AE7-8070

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes        Labels: 4E0-910-517.lbl
   Part No SW: 4E0 910 517 B    HW: 4E0 614 517 BC
   Component: ESP 5.7 allrad  H44 0510  
   Coding: 0008357
   Shop #: WSC 02313 000 00000
   VCID: 224B8DE9FD1E305282-8076

No fault code found.

-------------------------------------------------------------------------------
Address 05: Acc/Start Auth.        Labels: 4E0-910-131.lbl
   Part No SW: 4E0 910 131     HW: 4E0 909 131 C
   Component:     FBS AUDID3  H04 0140  
   Revision: 01404004    Serial number: AUX3Z0D9353518
   Coding: 0412672
   Shop #: WSC 02311 785 00200
   VCID: 58BFEF01EBC2AA82AC-800C

   Subsystem 1 - Part No: XXXXXXXXXXX 
   Component: ELV                 XXXX

No fault code found.

-------------------------------------------------------------------------------
Address 06: Seat Mem. Pass        Labels: None
   Part No SW: 4E0 910 760 C    HW: 4E0 959 760 
   Component: Sitzmemory BFS H08  0060  
   Revision: 00000000    Serial number: 5DS 008 795-03
   Coding: 3670112
   Shop #: WSC 02313 785 00200
   VCID: 234588EDE204395A89-8076

No fault code found.

-------------------------------------------------------------------------------
Address 07: Control Head        Labels: 4E0-910-7xx-07.lbl
   Part No SW: 4E0 910 769 Q    HW: 4E0 035 729 A
   Component: Interfacebox    H43 5570  
   Revision: 00000000    Serial number: 300KS047541498
   Coding: 0000002
   Shop #: WSC 00045 210 90242
   VCID: 3A7B5589758E5892BA-806E

   Subsystem 1 - Part No: 4E0 910 609 A
   Component: Bedienteil MMI  H42 0020

   Subsystem 2 - Serial number: 318IE047510004

   Subsystem 3 - Serial number: 7409.09.0400000000218B0053ÿ

   Subsystem 4 - Serial number: 8B0053ÿ

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC        Labels: None
   Part No SW: 4E0 910 043 A    HW: 4E0 820 043 A
   Component: KLIMAAUTOMAT    016 0340  
   Revision: 00000029    Serial number: 00000000057290
   Coding: 1067041
   Shop #: WSC 02311 785 00200
   VCID: 1B35B00DDA74019A41-804E

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect.        Labels: 4E0-910-279.lbl
   Part No SW: 4E0 910 279 L    HW: 4E0 907 279 L
   Component: ILM Fahrer      H12 0210  
   Coding: 0000001
   Shop #: WSC 02313 785 00200
   VCID: 316972A5A8F89BCA0B-8064

   Subsystem 1 - Part No: 4E2 910 113 B
   Component: Wischer WWS D3  H50 0420  
   Coding: 00000037
   Shop #: WSC 02313  

No fault code found.

-------------------------------------------------------------------------------
Address 0E: Media Player 1        Labels: 4E0-910-111.lbl
   Part No SW: 4E0 910 111 F    HW: 4E0 035 111 A
   Component: CD-Changer      H44 0470  
   Revision: 00000000    Serial number: AUZ5ZBD6029817
   Shop #: WSC 00000 000 00000
   VCID: 1C37B311DF7A06A248-8048

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags        Labels: 4E0-910-655-84.lbl
   Part No SW: 4E0 910 655     HW: 4E0 959 655 G
   Component: Airbag 8.4E+    H10 0940  
   Coding: 0431707
   Shop #: WSC 02313 785 00200
   VCID: 63C5C8EDA284795AC9-8036

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel        Labels: 4E0-910-549.lbl
   Part No SW: 4E0 910 549     HW: 4E0 953 549 
   Component: Lenksäulenmodul H13 0040  
   Coding: 0112141
   Shop #: WSC 02311 785 00200
   VCID: 65C1D6F5ACB0076A27-8030

   Subsystem 1 - Part No: XXXXXXXXXXX 
   Component: Lenkradmodul    H04 0080

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments        Labels: 4E0-910-xxx-17.lbl
   Part No SW: 4E0 910 950 F    HW: 4E0 920 950 F
   Component: KOMBIINSTR. VDO H49 0200  
   Revision: D03         Serial number: AUDID3DN000886
   Coding: 0000418
   Shop #: WSC 00028 210 01865
   VCID: 275D9CFD963CD57AD5-8072

No fault code found.

-------------------------------------------------------------------------------
Address 18: Aux. Heat        Labels: None
   Part No SW: 4E0 910 105 A    HW: 4E0 815 069 E
   Component: Heizgeraet      H07 0100  
   Revision: 0000000B    Serial number: 00000009006406
   Coding: 0000001
   Shop #: WSC 00000 000 00000
   VCID: 1A3BB509D54E78925A-804E

2 Faults Found:
01406 - No Flame 
            000 -  - 
02251 - Heater Unit Locked 
            000 -  - 

-------------------------------------------------------------------------------
Address 19: CAN Gateway        Labels: 4E0-910-468.clb
   Part No SW: 4E0 910 468     HW: 4E0 907 468 A
   Component: Gateway         H07 0070  
   Revision: 07          Serial number: 160030482517A7
   Coding: FCFF5BDE3B3504
   Shop #: WSC 02313 785 00200
   VCID: 65C1D6F5ACB0076A27-8030

No fault code found.

-------------------------------------------------------------------------------
Address 1D: Driver Ident.        Labels: 4E0-910-218.lbl
   Part No SW: 4E0 910 218     HW: 4E2 905 218 
   Component: FPI_1           H07 0060  
   Revision: 06000107    Serial number: 23092004154705
   Shop #: WSC 00000 000 00000
   VCID: 5EB3F91989E654B2E6-800A

No fault code found.

-------------------------------------------------------------------------------
Address 1E: Media Player 2 (R199)       Labels: 4E0-035-785.lbl
   Part No SW: 4E0 035 785 F    HW: 4E0 035 785 C
   Component: SG ext.Player H20 0850  
   Revision: 00000000    
   Coding: 010000
   Shop #: WSC 00000 000 00000
   VCID: 2B5560CD4AD4F11A31-807E

No fault code found.

-------------------------------------------------------------------------------
Address 25: Immobilizer        Labels: 4E0-910-131.lbl
   Part No SW: 4E0 910 131     HW: 4E0 909 131 C
   Component:     FBS AUDID3  H04 0140  
   Revision: 01404004    Serial number: AUX3Z0D9353518
   Coding: 0412672
   Shop #: WSC 02311 785 00200
   VCID: 58BFEF01EBC2AA82AC-800C

   Subsystem 1 - Part No: XXXXXXXXXXX 
   Component: ELV                 XXXX
   XXXXXXXXXXX ELV                 XXXX   

No fault code found.

-------------------------------------------------------------------------------
Address 34: Level Control        Labels: 4E0-910-553.lbl
   Part No SW: 4E0 910 553 H    HW: 4E0 907 553 F
   Component: LUFTFDR.-CDC    H06 4480  
   Coding: 0015510
   Shop #: WSC 02313 785 00200
   VCID: 285F9FC19B22DA02DC-807C

No fault code found.

-------------------------------------------------------------------------------
Address 36: Seat Mem. Drvr        Labels: None
   Part No SW: 4E0 910 760 C    HW: 4E0 959 760 
   Component: Sitzmemory FS  H08  0060  
   Revision: 00000000    Serial number: 5DS 008 795-03
   Coding: 3670126
   Shop #: WSC 02313 785 00200
   VCID: 234588EDE204395A89-8076

No fault code found.

-------------------------------------------------------------------------------
Address 37: Navigation        Labels: 4E0-910-88x-37.lbl
   Part No SW: 4E0 910 888 P    HW: 4E0 919 887 C
   Component: MNS ECE         H43 1060  
   Revision: 00000000    Serial number: 353K0047589079
   Shop #: WSC 02313 785 00200
   VCID: 3B75508D7AB4619AA1-806E

No fault code found.

-------------------------------------------------------------------------------
Address 38: Roof Electronics        Labels: 4E0-910-135.lbl
   Part No SW: 4E0 910 135 A    HW: 4E0 907 135 A
   Component: Dachknoten D3   H02 0090  
   Serial number: 00000430200115
   Coding: 0035904
   Shop #: WSC 02313 785 00200
   VCID: 1D31BE15C4600FAABF-8048

No fault code found.

-------------------------------------------------------------------------------
Address 42: Door Elect, Driver        Labels: 4E1-910-802-42.lbl
   Part No SW: 4E1 910 802 B    HW: 4E2 959 802 B
   Component: Türsteuer.FS BRM002 0060  
   Coding: 0026914
   Shop #: WSC 02311 785 00200
   VCID: 204F87E1F312224294-8074

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv.        Labels: 4E0-910-289.lbl
   Part No SW: 4E0 910 289 A    HW: 4E0 907 289 
   Component: Komfortgeraet   H04 0040  
   Revision: 00400004    Serial number:  W040411110043
   Coding: 0000249
   Shop #: WSC 02313 785 00200
   VCID: 275D9CFD963CD57AD5-8072

   Subsystem 1 - Part No: 4E0 910 853 
   Component: Heckdeckel   P14H06 0070

   Subsystem 2 - Part No: 4E0 907 719 
   Component: Neigungssensor  H03 0020

No fault code found.

-------------------------------------------------------------------------------
Address 47: Sound System        Labels: 4E0-910-223.lbl
   Part No SW: 4E0 910 223 P    HW: 4E0 035 223 A
   Component: DSP-Amp.-High   H13 0460  
   Revision: PROD_01     Serial number: 00000000008586
   Coding: 0000013
   Shop #: WSC 02313 785 00200
   VCID: 2A5B65C9852EE812CA-807E

No fault code found.

-------------------------------------------------------------------------------
Address 4F: Centr. Electr. II        Labels: None
   Part No SW: 4E0 910 280 A    HW: 4E0 907 280 A
   Component: ILM Beifahrer   H09 0040  
   Revision:             Serial number: 00000000051553
   Coding: 0010001
   Shop #: WSC 02313 785 00200
   VCID: 1E33B919C96614B2A6-804A

No fault code found.

-------------------------------------------------------------------------------
Address 52: Door Elect, Pass.        Labels: 4E1-910-802-52.lbl
   Part No SW: 4E1 910 802 B    HW: 4E2 959 801 B
   Component: Türsteuer.BF BRM002 0060  
   Coding: 0026914
   Shop #: WSC 02311 785 00200
   VCID: 204F87E1F312224294-8074

No fault code found.

-------------------------------------------------------------------------------
Address 53: Parking Brake        Labels: 4E0-910-801.clb
   Part No SW: 4E0 910 801 A    HW: 4E0 907 801 
   Component: EPB  AV1C1010   H01 1010  
   Revision: AV1C1010    
   Coding: 0000221
   Shop #: WSC 13765 210 01865
   VCID: 1D31BE15C4600FAABF-8048

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio        Labels: 4E0-910-541.lbl
   Part No SW: 4E0 910 541 T    HW: 4E0 035 541 B
   Component: TUNER EU/US/RDW H41 0630  
   Revision: 00000000    Serial number: 304KJ047604701
   Coding: 0000001
   Shop #: WSC 02313 785 00200
   VCID: 316972A5A8F89BCA0B-8064

No fault code found.

-------------------------------------------------------------------------------
Address 57: TV Tuner        Labels: 4E0-910-146.clb
   Part No SW: 4E0 910 146 G    HW: 4E0 919 146 A
   Component: TV analog TUNER H13 0300  
   Revision: 00000024    Serial number: 00000000008454
   Coding: 0000003
   Shop #: WSC 02313 785 00200
   VCID: 254196F5EC30C76AE7-8070

No fault code found.

-------------------------------------------------------------------------------
Address 61: Battery Regul.        Labels: 4E0-910-181.lbl
   Part No SW: 4E0 910 181 C    HW: 4E0 915 181 C
   Component: J0644 BEM       H11 0510  
   Revision: 00000000    Serial number: 00000000014066
   Shop #: WSC 00028 210 01865
   VCID: 204F87E1F312224294-8074

   Subsystem 1 - Part No: 4E0 915 105 DL
   Component: von VA0  310314E07G       
   Coding: 344530393135313035444C56413033313033313445303747
   Shop #: WSC 00011 888 06946

No fault code found.

-------------------------------------------------------------------------------
Address 62: Door, Rear Left        Labels: 4E0-910-802.lbl
   Part No SW: 4E0 910 802 A    HW: 4E0 959 801 C
   Component: Türsteuer.HL BRM002 0060  
   Coding: 0026914
   Shop #: WSC 02311 785 00200
   VCID: 1E33B919C96614B2A6-804A

No fault code found.

-------------------------------------------------------------------------------
Address 72: Door, Rear Right        Labels: 4E0-910-802.lbl
   Part No SW: 4E0 910 802 A    HW: 4E0 959 802 C
   Component: Türsteuer.HR BRM002 0060  
   Coding: 0026914
   Shop #: WSC 02311 785 00200
   VCID: 1E33B919C96614B2A6-804A

No fault code found.

-------------------------------------------------------------------------------
Address 76: Park Assist        Labels: 4E0-910-283.lbl
   Part No SW: 4E0 910 283 A    HW: 4E0 919 283 B
   Component: Parkhilfe 8-Kan H12 0020  
   Revision: --.--.--    Serial number: 08720430201074
   Coding: 0101008
   Shop #: WSC 02313 785 00200
   VCID: 214982E5F8182B4A9B-8074

No fault code found.

-------------------------------------------------------------------------------
Address 77: Telephone        Labels: 4E0-910-333.lbl
   Part No SW: 4E0 910 333 F    HW: 4E0 862 333 B
   Component: TELEFONMODUL EU     0770  
   Revision: 00000001    Serial number: 00000000000000
   Coding: 0000004
   Shop #: WSC 02313 785 00200
   VCID: 224B8DE9FD1E305282-8076

No fault code found.

End-------------------------(Elapsed Time: 03:47)--------------------------

 

[Uwe]

Please post up an Auto-Scan so we can see the exact ECU and instrument cluster part numbers.

There's at least some chance that the car has a dual temperature sensor, with separate circuits for the ECU and the cluster. Have you checked a wiring diagram?

-Uwe-

 

[Jack@European_Parts]

In addition to using VCDS advanced measuring blocks, I would review the WD in the RTFB, & to surmise the track or shared tracks.

Kind of hard to help without the JPPSG followed.
http://forums.ross-tech.com/showthr...essional-Problem-Solver-Guide-quot-JPPSG-quot

 

[mattylondon]

Hi Julian,

The coolant temperature sensor, G62, is a two pin type in the A8 D3 and is wired to the engine ECU. It can be measured in 01-Engine > measuring blocks > 04.

Is your temperature dial moving lower or higher than 90c? Do your radiator fans start?

 

[JulianHicks]

Thanks all: didn't realise this could get complicated

Uwe; Autoscan added to original thread starter

Jack; a) not sure where I'd find a wiring diagram - I'm just an amateur. b) Not sure the US guides [Bentley] are much use for Euro models with Diesel engines.

Matty; a) thanks for suggested starting point. [Are you suggesting it's not a dual ECU type]? b) Moves lower than 90C [and takes longer to reach 90]. Not sure if fans start ...

Thanks - Julian

 

[Uwe]

Measuring block 005, field 4 in the ECU. Cross-check against what you see in the instrument cluster, MVB 003, field 1.

For reference purposes, see: Where do I get a Wiring Diagram?.

Based on what you've written though, my money is on a thermostat that isn't closing fully.

-Uwe-

 

[Jack@European_Parts]

I agree with Uwe.....T-stat seems sticky, or a fan could be sticking on due to poor ground or signal to fan control module.

Thank you for posting the scan.....

 

[JulianHicks]

Measuring block 005, field 4 in the ECU. Cross-check against what you see in the instrument cluster, MVB 003, field 1.
...
-Uwe-

Thermostat - coming to that conclusion too.

Out of interest, drove it and left it running outside my house with VCDS plugged in. Gauge on panel spot on at 90; stayed that way for 15 mins, then went left a fraction.

Water temp 80.1 at both Engine ECU and Panel ECU - panel obviously not telling the truth What temperature would one expect to see in 'normal operation'?

Note: Temperature cluster field found as described; Engine ECU field in MVB 001, field 4 and MVB 002, field 4; didn't go up to MVB 5! Field labelled with "G62".

Thanks again - Julian

 

[Uwe]

Instrument cluster temperature gauges in VAG products have told little white lies for more than 20 years now. They're programmed such that within a certain acceptable range of temperatures, they show a steady 90°C.

80°C at idle is probably about right/normal in a diesel.

You might want to log temperature during an actual test drive to see what it does, especially when the gauge drops below an indicated 90°C.

-Uwe-

 

[JulianHicks]

You might want to log temperature during an actual test drive to see what it does, especially when the gauge drops below an indicated 90°C.

-Uwe-

So I did do a test drive today - went from home to a town [city] 15 miles away [20 mins], stopped to shop [10 mins], drove home again [20 mins].

Conditions: External temp - 12C/54F. Driving speed - reasonably constant 55mph. Simplified results from VCDS MVB CSV file below [Coolant temp / elapsed time]:

Temp Time
20C 0 mins
30C 1.5 mins
40C 3.4 mins
50C 6 mins
60C 15 mins - 20 mins stopped.
60C 30 mins [includes 10min shopping]
70C 35 mins
70C 35 mins - 50 mins [never got above this]

Temp gauge correctly started moving at 50C and was accurate to about 65C. But after about 68C always read higher [up to about 85] but never got to 90C

Julian

 

[Uwe]

Seems to me it should get warmer than that under load.

But hard to say whether the problem is wrong readings from the temp sensor or a thermostat that's not controlling water flow correctly. I'd guess the latter.

-Uwe-