Audi A3 8L temp gauge not working

[AndreP106]

Hi everybody
so I´ve tried everything now but still no reading from the gauge.
My climate control shows the temp and VAG-COM also reads temperature and now I got the check the instruments and Output settings shows all the gauges are calibrated properly.
Can it be that one of the pins just doesn´t give siganl to the cluster?

Andre

 

[<tuffty/>]

Have you looked at temperature in both engine and instrument modules?

<tuffty/>

 

[AndreP106]

Do you mean if I tried measuring blocks in the instrument module?
I didn´t know this would give me a separate reading, so only done it in engine module.

 

[<tuffty/>]

There are two sensors in the CTS... one is for the ECU (engine module) the other is for the instruments... its fairly common for them to read differently and very common for the CTS to be faulty

Check the instruments module but I suspect the issue here is the CTS

<tuffty/>

 

[AndreP106]

Checked it on my other A3 and does really work, the one with the problem is at my work so I´ll check the instrument reading there!
But the one at home has a problem with the fuel gauge. It shows over full when actualy has 47L inside.
Output test also leaves it at 3/4 not in the middle, haven´t found a way to get past this problem yet, only dead ends.
Display also shows the correct milage left so it shouldn´t be the sender unit.
Adaption also doesn´t help because 120 on the level doesn´t even move it...

 

[AndreP106]

Mistery solved, thanks again Tuffy!!!
Couldn´t find any topics that said it gives out two readings so going to change that.
Now it´s just figuring out what to do with the fuel gauge on my daily...

 

[MrT___wind]

I have the same problem.
I did the Aircon code 49, to see the coolent temp. It started at 5c and went up to about 80c, and the gauge was working, then the gauge stopped and the reading on the Aircon, started falling, it droped to - 10c.
Any idea what need replacing?
Thanks

 

[s3mad_dude]

I’ll put money on the coolant temp sender with those symptoms. I just replaced mine actually because my gauge started falling/rising. If you have VCDS you can analyse and diagnose to your heart’s content but I’d bet a tenner on a fault with the temp sensor. Very easy to replace. Buy a genuine part if you can, along with a new O-ring, plastic retaining clip and some G13+ pre-mixed coolant too because you’ll need to drain the cooling system a bit first. If you don’t drain it, when you unplug the sensor, the fluid will gush out until the level drops below. If that happens you’ll need about 1L to replace. There’s a handy drain point at the bottom of the radiator hose which is better to use.

 

[rsvr]

Stepper motors in the cluster are known to be junk in earlier models and cause this too