Audi A3 8L Temperature Gauge Fault

[Hyakisan]

Hello everyone, I have a 2002 A3 8L 1.9 TDI ATD with the 5-speed automatic Gearbox.

The issue is that the coolant temperature gauge functions normally most of the time but will suddenly climb to the high temperature then the radiator fan will start running at high speed. I am not really sure about that but I notice that happens when I am breaking hard.

I already changed the engine coolant temperature sensor (febi) and the water pump.

I observed the coolant temperature live data with the diagnostic tool connected, in the engine ECU was around 90 degrees which is normal but when I observed in the instrument cluster, I see value like 120 degrees when I see these values the radiator fan was at high speed.

Sometime when I drive the gauge come back to his normal position 90 degrees.

In the instrument Cluster I read the fault code below:

00668 053: Vehicle voltage terminal 30

Voltage Supply too low

I didn’t have any other fault code in the engine ecu.



Any thoughts and advice are much appreciated.

 

[PetrolDave]

Please post an Auto-Scan made using the English version of VCDS and which is not edited so we can see how your A3 is equipped and configured.

 

[aceton]

Coolant level ?
Air in coolant ?
Measure the temperature with an independent thermometer when you see 120*

 

[Hyakisan]

Please post an Auto-Scan made using the English version of VCDS and which is not edited so we can see how your A3 is equipped and configured.

Thanks for your reply but I am using Odis 7.1, as I said before I didnt have any ohter ecu message, but one time I read the fault code : 18058 Powertrain data bus missing message from instrument cluster in Engine ECU.
Thanks for your help.

 

[Hyakisan]

Coolant level ?
Air in coolant ?
Measure the temperature with an independent thermometer when you see 120*

Coolant Level is Ok, Dont think that there is air in coolant, Sometimes I see 120* the morning at first start when outside is 0*. As I said when I see 120* on cluster in the Engine ecu I read 90* wich is correct.

 

[PetrolDave]

Thanks for your reply but I am using Odis 7.1

Then you need to ask on an ODIS support forum, this site is run by Ross-Tech for owners of their tool VCDS.