Q5 temp sensor fault question

[Cambs55]

My Q5 threw up an amber engine light on the dash, mpg has been maybe 5mpg lower than normal, and the start-stop occasionally won't work.

VCDS says there is a problem with "temp sensor 3". Any ideas how, without pulling the car apart, I can identify what temp sensor 3 is?

Thursday,20,October,2022,15:43:42:03339
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 11 arm64(arm64 CPU)(Parallels)
VCDS Version 22.9.0.0 (arm64)  HEX-V2 CB: 0.4623.4
Data version: 20220830 DS341.0
www.Ross-Tech.com


VIN: WAUZZZ8R1GA044269   License Plate:


Chassis Type: 8R-AU48 (8R0)
Scan: 01 02 03 05 08 09 15 16 17 19 42 44 46 52 53 56 5F 62 6D 72
          AC

VIN: WAUZZZ8R1GA044269   Mileage: 129070km-80200miles

01-Engine -- Status: Malfunction 0010
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
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- 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
42-Door Elect, Driver -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
53-Parking Brake -- Status: OK 0000
56-Radio -- Status: OK 0000
5F-Information Electr. -- Status: OK 0000
62-Door, Rear Left -- Status: OK 0000
6D-Trunk Elect. -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
AC-Reductant Control -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine (J623-CTBA)       Labels:. 059-907-401-V2.clb
   Part No SW: 8K5 997 401 E    HW: 4G0 907 401 E
   Component: 3.0TDI EDC17  H14 0002 
   Revision: 58H14---    CVN: BE7D205AC19C777138D3FF82
   Coding: 2A254012052703030000
   Shop #: WSC 02422 002 1048576
   ASAM Dataset: EV_ECM30TDI0118K5997401E 001002
   ROD: EV_ECM30TDI0118K5997401D.rod
   VCID: 3B2336F433E57063F21-806F
   VINID: 9D196AAAA2220574401040862432A7E560

1 Fault Found:
21501 - Engine Coolant Temperature Sensor 3
          P01E3 00 [038] - Electrical Malfunction
          Intermittent - Not Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 10
                    Mileage: 129056 km
                    Date: 2022.10.20
                    Time: 14:09:01

                    Engine RPM: 685.00 /min
                    Normed load value: 27.8 %
                    Vehicle speed: 0 km/h
                    Coolant temperature: 59 °C
                    Intake air temperature: 21 °C
                    Ambient air pressure: 990 mbar
                    Voltage terminal 30: 14.420 V
                    Unlearning counter according OBD: 40
                    Accelerator pedal travel: 0.00 %
                    Coolant temperature at radiator outlet: actual value: 25.6 °C
                    Heat delivery temperature in cooling system: 43.3 °C
                    Outside temperature: 17.5 °C
                    Fuel consumption: 0.77 l/h
                    Fuel temperature: 22.5 °C
                    Engine oil temperature: 57.5 °C

Readiness: 0 0 0 0 0

-------------------------------------------------------------------------------
Address 02: Auto Trans (J217)       Labels:| 0B5-927-156.clb
   Part No SW: 8R2 927 156 P    HW: 0B5 927 156 K
   Component: 0B5 30 TDIRdW H03 0009 
   Revision: --H03---    CVN: 0000313E
   Coding: 000001
   Shop #: WSC 06335 000 00000
   ASAM Dataset: EV_TCMDL501021 001021
   ROD: EV_TCMDL501021.rod
   VCID: 4ACD63306C3FD9EB797-801F

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104)       Labels:. 8R0-907-379-V2.clb
   Part No SW: 8R0 907 379 BA    HW: 8R0 907 379 BA
   Component: ESP8 quattro  H09 0020 
   Revision: --------    Serial number: --------------
   Coding: 2F5DCC01
   Shop #: WSC 06335 000 00000
   VCID: 005981181A03D3BBE73-8055

No fault code found.

-------------------------------------------------------------------------------
Address 05: Acc/Start Auth. (J393)       Labels:. 8K0-907-064-05.clb
   Part No SW: 8K0 907 064 KG    HW: 8K0 907 064 KG
   Component: BCM2 2.0      H15 0711 
   Revision: 00002001   
   Coding: 01B54040000000000000
   Shop #: WSC 06335 000 00000
   VCID: 7F5B02E467FDAC439E9-802B

   Subsystem 1 - Part No SW: 8K0 959 754 H    HW: 8K0 959 754 H
   Component: FBSAUDIB8 IDG  H71 0083
   Serial number: 0815000092832021   

   Subsystem 2 - Part No SW: 8K0 905 852 E    HW: 8K0 905 852 E
   Component: J764 ELV MLB  H40 0046
   Serial number: 3215000132151001   

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J255)       Labels:. 8Kx-820-043-3Z.clb
   Part No SW: 8K2 820 043 AQ    HW: 8K2 820 043 AQ
   Component: KLIMA 3 ZONEN H04 0122 
   Revision: D1000000    Serial number: 01060820152414
   Coding: 3625028000
   Shop #: WSC 06335 000 00000
   VCID: 78A9E9F842D39B7BDF3-802D

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519)       Labels:. 8K0-907-063.clb
   Part No SW: 8K0 907 063 DH    HW: 8K0 907 063 DH
   Component: BCM1 1.0      H16 0103 
   Revision: 08016001    Serial number: 00001144385101
   Coding: 260000108034AFE01581408300001D0D4F9D470827090201000008004400030100000024000000
   Shop #: WSC 06335 123 12345
   VCID: 78A9E9F842D39B7BDF3-802D

   Subsystem 1 - Part No SW: 8R2 955 119 A    HW: 8R2 955 119   Labels: 1KX-955-119.CLB
   Component: WWS416 150716  H12 0050
   Serial number: 90243015150615181953
   Coding: 01DD13

   Subsystem 2 - Part No SW: 8U0 955 559 C    HW: 8U0 955 559 B  Labels: 8U0-955-559.CLB
   Component: G397_RLFS  H06 0004
   Serial number: 20502958           
   Coding: 02005C

   Subsystem 3 - Part No SW: 8K0 941 531 AS    HW: 8K0 941 531 AS
   Component: E1 - LDS  H03 0031
   Serial number: 00000000002807151240

   Subsystem 4 - Part No SW: 4H0 907 658     HW: 4H0 907 658
   Component: AQ_Hum_Sensor  H03 0003
   Serial number: 07798FB7000000000001

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags (J234)       Labels:* 8R0-959-655.clb
   Part No SW: 8R0 959 655 G    HW: 8R0 959 655 G
   Component: AirbagVW-AU10 H49 0610 
   Serial number: 003JPDD0GXMF 
   Coding: 30473531313030303030554A305238523053
   Shop #: WSC 06335 000 00000
   ASAM Dataset: EV_AirbaAU10SMEAU416 002004
   ROD: EV_AirbaAU10SMEAU416.rod
   VCID: 48C9593872332BFB6F3-801D

   Crash sensor for side airbag: driver side:
   Serial number: 6334MSME530930744

   Front Passenger's Side Airbag Crash Sensor:
   Serial number: 6344MSME530A6F79T

   Rear Side Airbag Crash Sensor (on driver's side):
   Serial number: 6352QSME57582464I

   Passenger side rear thorax airbag crash sensor:
   Serial number: 6362QSME79582D40Q

   Crash sensor for front airbag: driver side:
   Serial number: 63732SME74522472W

   Crash sensor for front airbag: front passenger side:
   Serial number: 63832SME74521950X

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel (J527)       Labels:. 8K0-953-568.clb
   Part No SW: 8K0 953 568 Q    HW: 8K0 953 568 Q
   Component: Lenks.Modul   H03 0003 
   Revision: C0062331    Serial number: 90862OH6000TC
   Coding: 000037
   Shop #: WSC 06335 000 00000
   VCID: 48C9593872B32BFB6F3-801D

   Component: E221 - MFL  H03 0004

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285)       Labels:. 8R0-920-xxx-17.clb
   Part No SW: 8R0 920 981 P    HW: 8R0 920 981 P
   Component: KOMBIINSTR.   H35 0567 
   Revision: 00200000    Serial number: 03828558G    
   Coding: 33A6220003012600010000
   Shop #: WSC 06335 000 00000
   VCID: 47CB5A047FAD2483669-8013

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway (J533)       Labels:. 8T0-907-468.clb
   Part No SW: 8R0 907 468 T    HW: 8R0 907 468 C
   Component: GW-BEM 4CAN-M H11 0070 
   Revision: 1Y090032    Serial number: 3241Y1570705FA
   Coding: 80CF07FF00
   Shop #: WSC 06335 000 00000
   VCID: 50F971588AE3E33B373-8005

   Subsystem 1 - Part No SW: 8R0 915 181 C    HW: 8R0 915 181 C
   Component: J367-BDMHella  H07 8043
   Serial number: 0476607403         

   Subsystem 2 - Part No SW: 8K0 959 663     HW: 8K0 959 663
   Component: J532_DCDCStab  H17 0042
   Serial number: 14023001732011200181

No fault code found.

-------------------------------------------------------------------------------
Address 42: Door Elect, Driver (J386)       Labels:. 8K0-959-793.clb
   Part No SW: 8K0 959 793 R    HW: 8K0 959 793 P
   Component: TSG FA        H02 0511 
   Revision:             Serial number: 0000160604337
   Coding: 011D02215C01440004
   Shop #: WSC 06335 000 00000
   VCID: 4FFB722497DDFCC32E9-801B

No fault code found.

-------------------------------------------------------------------------------
Address 44: Steering Assist (J500)       Labels:| 8K0-909-144.clb
   Part No SW: 8R0 909 144 P    HW: 8R0 909 144 B
   Component: RCEPS         H43 0510 
   Revision: 00001000    Serial number: 0022058887
   Coding: 100000000001
   Shop #: WSC 06334 000 00000
   ASAM Dataset: EV_RCEPSAU48X 008018
   ROD: EV_RCEPSAU48X_008.rod
   VCID: 45D7500C45213693945-8011

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv. (J393)       Labels:. 8K0-907-064-46.clb
   Part No SW: 8K0 907 064 KG    HW: 8K0 907 064 KG
   Component: BCM2 2.0      H15 0711 
   Revision: 00002001    Serial number: 0376479057   
   Coding: 013B0622A0B930808720053680040047
   Shop #: WSC 06335 000 00000
   VCID: 7F5B02E467FDAC439E9-802B

   Subsystem 1 - Part No: 8K0 951 177
   Component: DWA-Sensor  H02 0040

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

No fault code found.

-------------------------------------------------------------------------------
Address 52: Door Elect, Pass. (J387)       Labels:. 8K0-959-792.clb
   Part No SW: 8K0 959 792 R    HW: 8K0 959 792 P
   Component: TSG BF        H02 0511 
   Revision:             Serial number: 0000161068092
   Coding: 011D02215E01440004
   Shop #: WSC 06335 000 00000
   VCID: 4EC56F2090D7F5CB25F-801B

No fault code found.

-------------------------------------------------------------------------------
Address 53: Parking Brake (----)       Labels: 8K0-907-801-V2.clb
   Part No SW: 8K0 907 801 N    HW: 8K0 907 801 J
   Component: EPB-4         H02 0005 
   Revision: --------    Serial number: 10000000576556
   ASAM Dataset: EV_ParkiBrake 001028
   ROD: EV_ParkiBrake_AU48.rod
   VCID: 3A2D33F03CDF496BE97-806F

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio (R)       Labels:. 4F0-035-0xx-56.clb
   Part No SW: 4G0 035 061 Q    HW: 4G0 035 061
   Component: Radio U DAB   H60 0150 
   Revision: AB001007    Serial number: 109H20F8059905
   Coding: 010103020100000001
   Shop #: WSC 06335 000 00000
   VCID: 2B0306B4C305E0E3621-807F

No fault code found.

-------------------------------------------------------------------------------
Address 5F: Information Electr. (J794)       Labels:. 4E0-035-6xx-5F.clb
   Part No SW: 8R2 035 670 K    HW: 8R2 035 670 J
   Component: H-BNT-EU      H50 0941 
   Revision: --------    Serial number: 517GX0F7504312
   Coding: 160101060005E1ED05808B5E00000403040000000000000000
   Shop #: WSC 06335 000 00000
   VCID: 3C2135E8366B775BFBB-8069

   Subsystem 1 - Part No: 8R0 060 884 CR
   Component: EUR 2015  2102

   Subsystem 2 - Part No SW: 8R0 919 604 A    HW: 8R0 919 604 A
   Component: DU7 High  H42 0104
   Serial number: A130HU0F3431853    

   Subsystem 3 - Part No SW: 8T0 919 611 K    HW: 8T0 919 611 B
   Component: E0380 Bedient  H02 0030
   Serial number: 00000002332423     

   Subsystem 4 - Part No: 8R0 060 961 G
   Component: CD-Database  6208

No fault code found.

-------------------------------------------------------------------------------
Address 62: Door, Rear Left (J388)       Labels:. 8K0-959-795.clb
   Part No SW: 8K0 959 795 G    HW: 8K0 959 795 D
   Component: TSG HL        H01 0510 
   Revision:             Serial number: 0000160498807
   Coding: 010C02204001240004
   Shop #: WSC 06335 000 00000
   VCID: 46D5570078A73D8B9DF-8013

No fault code found.

-------------------------------------------------------------------------------
Address 6D: Trunk Elect. (J605)       Labels: 8K9-827-851.clb
   Part No SW: 8R0 827 851 D    HW: 8R0 827 851 D
   Component: J605  Master  H56 0330 
   Revision: --------    Serial number: 8R0827851D   
   VCID: 3D2738EC2D717E53CC5-8069

   Subsystem 1 - Part No SW: 8R0 827 852 D    HW: 8R0 827 852 D
   Component: J756  Slave  H56 0330
   Serial number: 8R0827852D         

No fault code found.

-------------------------------------------------------------------------------
Address 72: Door, Rear Right (J389)       Labels:. 8K0-959-795.clb
   Part No SW: 8K0 959 795 G    HW: 8K0 959 795 D
   Component: TSG HR        H01 0510 
   Revision:             Serial number: 0000160501554
   Coding: 010C02204001240004
   Shop #: WSC 06335 000 00000
   VCID: 46D5570078A73D8B9DF-8013

No fault code found.

-------------------------------------------------------------------------------
Address AC: Reductant Control (J880)       Labels: 4G0-907-355.clb
   Part No SW: 4G0 907 355 G    HW: 4G0 907 355 B
   Component: SCR-Stg-G2    H10 0013 
   Revision: 00000000    Serial number: 151870281
   ASAM Dataset: EV_RDCMA00100 008040
   ROD: EV_RDCMA00100.rod
   VCID: 2F3B12A4F79D9CC34E9-807B

No fault code found.

End----------(Elapsed Time: 01:46, VBatt start/end: 12.3V/12.3V)-----------

 

[Bruce]

VCDS says there is a problem with "temp sensor 3". Any ideas how, without pulling the car apart, I can identify what temp sensor 3 is?

To find the location of temp sensor 3, I'd confer with the official factory repair information. Access to it can be purchased for a small fee.

Official Factory Repair Information

 

[Cambs55]

Thanks, I'll take a look. Perhaps related but I have noticed the in dash temp needle jumps around somewhat randomly. From around 60C to around 75C and back again. I managed to log this just now, and caught it jumping from 60C to 74C in 0.14 seconds, and then staying at 74-75C. Not possible surely? Where does the in dash temp gauge read from? I am aware it is damped/fiddled, but jumping so quickly does indicate a fault no?

 

[Jef]

Not sure what Coolant Temp Sensor #3 is. Everything I find shows just 2 coolant temps sensor, the classic G62 and then one on the radiator outlet G83. Repair info give little clues beyond a statement of:

Malfunction Criteria and Threshold Value: Signal voltage > 4.92 V

So maybe some fun things to look at:

• IDE00025-ENG167462 - Coolant temperature
• IDE00192 - Coolant temperature at radiator outlet: actual value
• IDE04256 - Temp sensor for engine coolant: unconditioned voltage
• IDE03377 - Coolant temp at radiator output: unconditioned voltage

When you go into Advance Measuring Values, at the top of the new window that opens, just type in 5 digit number to filter out everything else to find those things. So for example, type in 04256 will filter out everything but that IDE04256 location.

 

[Cambs55]

Thanks Jef. I've been monitoring the temps but not the voltages at the same time. Will keep an eye out for anything unusual

 

[Cambs55]

Nothing seems unusual in the data (I think), but I'm still getting the fault code in vcds, and the in dash temp needle does sometimes jump around randomly. My local garage suggested temp sensor 3 could relate to another sensor-not the coolant one. Perhaps an EGR one which does have 3. Will monitor these and see.
Meanwhile, here's a trace for the data Jef suggested monitoring.

https://imgur.com/a/ShcFUu3

 

[Uwe]

and the in dash temp needle does sometimes jump around randomly.

That shouldn't happen.

-Uwe-

 

[Cambs55]

https://imgur.com/a/BAMZXAP

This chart is a log of the in-dash temp needle

Is there any way to log the in dash temp along with temp sensors from different modules? Or if anyone knows which sensor(s) the in dash needle uses, that would be really helpful. The coolant sensor logs all seem normal I think. Maybe rad output is a bit low?

 

[Cambs55]

Just managed to capture a longer log of the in dash temp needle behaviour:

https://imgur.com/a/P4b9PWs

 

[Uwe]

Just managed to capture a longer log of the in dash temp needle behaviour:

There's definitely something dodgy going on there!

-Uwe-

 

[Cambs55]

Found it! G321 is the source of the signal for the in dash temp needle, and is clearly wonky:

https://imgur.com/a/exjCUFa

Now to work out where G321 is....

 

[Cambs55]

So, turns out that G321 doesn't exist according to my garage. Anybody out there know which sensor is used for the in-dash temperature needle.......?

 

[davisev5225]

So, turns out that G321 doesn't exist according to my garage. Anybody out there know which sensor is used for the in-dash temperature needle.......?

You measured its value using VCDS since you were able to post a graph, so clearly it does exist on your car. Why would you believe your garage's word over what you've directly observed using diagnostic tools?

 

[Uwe]

You measured its value using VCDS since you were able to post a graph, so clearly it does exist on your car.

It's possible it's not called G321 in that car. VAG has had the nasty habit of re-labeling things of late.

-Uwe-

 

[Cambs55]

I think you are right Uwe. The garage called tps and they had no sensor with a g321 code (they are familiar with g-codes). So I’m looking for the part number for the sensor that feeds the in dash reading. Trying to avoid going to an Audi dealer for obvious reasons

 

[Jef]

Was wondering where you got "G321"... pulling the curtain back a little... 321 is a reference number in the VCDS software, kind of #321 item listed.

Check the actual coolant temp sensor, G62. Unplug it and see what happens to your live data.

 

[Cambs55]

I got g321 from the csv log file-reading from the engine module, not instrument. The readings seem to behave the same that the engine temp does when logging from the instrument module, so I am assuming this is the source. Any idea what part number or where I find g62?

 

[Jef]

079 919 523 H
Location... I'm not sure I can give a good answer there. I'm using a different engine code to look this up and the tech drawing it shows is rather... well, it is on the left half of the engine... and I think it might be under the intake manifold....

Some one want to confirm or correct that statement?

 

[Cambs55]

Thanks Jef. I think the UK part for my car is this one: https://www.autodoc.co.uk/hella/937882

I also found this: https://f01.justanswer.com/drhorsefield/4c7f023c-4d9d-4fd3-ad2f-b9cebe2c5e3b_TEST4.pdf
It's for a 2l and mine is a 3l, but it looks similar.

Oh, and also found this which may or may not help

Will investigate in the morning when it's light...

 

[Cambs55]

So, I managed to pry the harness off a temp sensor at the front of the engine under the throttle body. I believe it's the block circuit temperature sensor in the YouTube video above. My G321 reading went straight to -40C, so this is the one. Slightly odd thing is that the in dash temp needle didn't change, but I don't think this matters. Will sort out another sensor (part no. as you suggested Jef 079 919 523)