A question about an A6 C8 engine fault warning light

[GokartMozart]

I recently bought a 2019 plate A6 Avant. After 5 weeks the amber emission control system icon appeared and won't go away. It doesn't flash. I took it back to the approved used Audi dealer I bought the car from, who put it on a ramp for diagnostics.

They showed me a dent in the heat shields on the underbelly and told me that a communication was lost between X and Y (a sensor needed replacing). Their cost to repair is not insignificant.

They were able to pinpoint exactly what time and what day the fault light came on (through the diagnostics). This was exactly 5 weeks after I had bought the car.

My question (and please note that I'm no techy) is: could the problem have been there BEFORE the light came on, i.e. could the sensor have been damaged, and the fault light not shown up immediately. Could the damage have existed I bought the car. I don't remember any rocks being kicked up, nor scraping any speed bumps.

Thank you.

[jammy]

8 hours ago, GokartMozart said:

I recently bought a 2019 plate A6 Avant. After 5 weeks the amber emission control system icon appeared and won't go away. It doesn't flash. I took it back to the approved used Audi dealer I bought the car from, who put it on a ramp for diagnostics.

They showed me a dent in the heat shields on the underbelly and told me that a communication was lost between X and Y (a sensor needed replacing). Their cost to repair is not insignificant.

They were able to pinpoint exactly what time and what day the fault light came on (through the diagnostics). This was exactly 5 weeks after I had bought the car.

My question (and please note that I'm no techy) is: could the problem have been there BEFORE the light came on, i.e. could the sensor have been damaged, and the fault light not shown up immediately. Could the damage have existed I bought the car. I don't remember any rocks being kicked up, nor scraping any speed bumps.

Thank you.

It’s possible but unlikely.

How close is the proximity of the sensor to the damaged heat shield?

Is there physical (visible) damage to the  sensor?

 

 

[GokartMozart]

5 hours ago, jammy said:

It’s possible but unlikely.

How close is the proximity of the sensor to the damaged heat shield?

Is there physical (visible) damage to the  sensor?

 

 

I'm not sure to either of those questions. They showed me (via webcam) impact damage to the shield which they think was caused by a stone kicking up. They think this has caused a fuse to blow and will need to look at the wiring behind the shield. 

I think it's unlikely as well, that the fault light didn't come on immediately. I just wanted to know a little more, before I went ahead with the work. Thanks for replying jammy.

[jammy]

1 hour ago, GokartMozart said:

I'm not sure to either of those questions. They showed me (via webcam) impact damage to the shield which they think was caused by a stone kicking up. They think this has caused a fuse to blow and will need to look at the wiring behind the shield. 

I think it's unlikely as well, that the fault light didn't come on immediately. I just wanted to know a little more, before I went ahead with the work. Thanks for replying jammy.

It is more likely that the damaged heatshield has no bearing to the failed sensor than the original question you asked.

if it was me I would be wanting to get them to give me more details about the relationship of the sensor location and the damage they have shown you.

it may be the actual reason, but don’t take it at face value right now.