Hi, I have a 2010 Skoda superb MK2 elegance 170tdi. A few days ago I started the car and within 5-10seconds smoke started appearing from behind the dash, I would believe passenger side(left) more than drivers side. I left the car and unplugged the battery. Today I have gone out with vcds and done a auto scan, found out the following but have no idea where to look first.

Engine:

P0196 00 [047]

Engine oil temp sensor G8

Implausible signal

Auto HVAC:

B10AE 14 [009]

High pressure sensor

Open/short to ground

B10AF 04 [008]

Air Quality Sensor

Internal system fault

B10A4 15 [009]

Signal line for air quality sensor

Open or short to plus

Instruments:

B1041 35 [009]

Oil level thermal sensor

Signal high time > maximum

I'm thinking the G8 sensor and high pressure sensor share the same power line and maybe a fault lies somewhere around here

Something has clearly burnt out due to the amount of smoke and smell, it's definitely electrical, where are some of these things located and where/what should I check first? Am I right saying glovebox off and inspect behind that area?

Thank you everyone any help is genuinely appreciated, I'm on with mechanical work usually, electrics aren't my favourite lol.

Hello, welcome to the forum.

I'd suggest first locating and taking a look at the fan speed control resistor.

If that's not burnt, take a look at the air quality sensor, which is, I believe, in the airstream supply to the cabin heating system.

On 14/02/2026 at 08:58, Warrior193 said:

I'd suggest first locating and taking a look at the fan speed control resistor.

and the fan?

7 hours ago, bigjohn said:

and the fan?

Possibly, but reports I've seen on the forum suggest most common failure is the resistor block.

1 hour ago, Warrior193 said:

Possibly, but reports I've seen on the forum suggest most common failure is the resistor block.

It was the report of smoke behind the dash. A resistor pack can die but will fail open circuit(low fan speeds not then working). A motor can fail (consuming too much current)/ or brushes wearing out (arcing) - this MIGHT generate smoke from the motor and/or resistor pack if in use as it'll be in series to the motor. To generate smoke etc you need highish current.

Edited 17 February17 Feb by bigjohn

Thank you both @bigjohn @Warrior193

I managed to have a look today as it was dry for once lol is this the resistor you're talking about?

Could this be what caused the smoke? Looks burnt out

No pins or wires look burnt on it or around it though

Part number: 3C0907521F

Edited 19 February19 Feb by clivedavis

Unable to say what that is, where was it located?

@Warrior193 it's the resistor in the blower fan

Ah, right! - that will be a heatsink, the resistor will be beneath it

1 minute ago, Warrior193 said:

Ah, right! - that will be a heatsink, the resistor will be beneath it

Ok cool :) I'll replace the both the fan and the heatsink with resistor and see how it gets on, I'll report back! Thank you!

Is the fan rotor free to turn by hand - or does it feel stiff/seized?

17 hours ago, Warrior193 said:

Is the fan rotor free to turn by hand - or does it feel stiff/seized?

I'm going to check when the part arrives hopefully within the hour, weird how it's got all that white stuff all over it even if it's not the problem surely that needs to be replaced,

20 hours ago, Warrior193 said:

Is the fan rotor free to turn by hand - or does it feel stiff/seized?

This is the old one, it turns freely but does smell of the electrical smoke smell. Replaced this and now I get

Engine:

P0196 00 [047]

Engine oil temp sensor G8

Implausible signal

Auto HVAC:

B10AE 14 [009]

High pressure sensor

Open/short to ground

B10A4 15 [009]

Signal line for air quality sensor

Open or short to plus

The engine oil temp with vcds shows 79.3° and the instrument engine oil values show -58° they seem to be stuck. I'm stumped right now I have no idea what to check next. The old fan blower I don't think looks too bad, but the heatsink has all that white stuff on where it maybe could have overheated, pins look fine.