Ibiza 6L Cupra TDI glow plug relay

Hello everyone.
My name is Manuel, I'm 28 years old, and I come from Murau in Austria. I'm completely addicted to [something - the original text uses a slang term that needs context].
I've only recently started dealing with diesel engines because my girlfriend...
He bought an Ibiza Cupra TDI with a BPX engine.
I have to say, it's a really awesome car.

But now, let's get to the problem:

It starts relatively hard when the temperature is below 0 degrees Celsius.
Until yesterday, the preheating light wasn't working either.
I was able to get it working again by resoldering the LEDs in the dashboard.
Attempted to start again today:

The glow plug indicator light comes on for about 2 seconds, but the engine still starts poorly.


Where is the glow plug relay located in this car?

Thank you in advance.

Best regards, Manuel.

Hello.

I would suggest looking for a dual temperature sensor (green/4-pin) in that area instead.
It is located at the cooling water outlet below the tandem pump, towards the passenger compartment.
Part No. 059919501A

A simple test would be to disconnect the sensor; in that case, the MSTG (Multi-Spark Timing Generator) will always initiate the pre-glow process.
If all the glow plugs are working correctly, the engine should start well, and in that case, the sensor would need to be replaced.
Another option would be to read the relevant data (coolant temperature, fuel temperature, and intake air temperature) using VCDS.
When the system is cold, all sensors should display approximately the same temperature values.


Regards,
Mpire

Hi, thanks for the reply.

There is an update.
All temperature sensors are functioning correctly.
No error is stored either.

I've now checked the glow plugs and disconnected the relay so I can manually pre-heat them.
The next day I tried again, and sure enough, it still started with difficulty.
Even though I manually preheated it for about 10 seconds at around 0 degrees Celsius.
So, it can only be a diesel-related problem now...
But what about...