Originally Posted by Prolific2

In the last three months had to be towed in three times for overheating. Warning to shut the engine off "cooling system malfunction". Sometimes intermittent. During episodes radiator is cool, fans running like crazy. First time dealer thought it was sensor controlling flow to radiator, not necessarily thermostat per se, but they found water pump leak fouling the sensor when they went to change the sensor. Next time they felt it was a coolant reservoir sensor problem and they replaced the coolant reservoir. Currently in the shop again and this time they've been advised by Audi technical consultant to "re-pin " a sensor connection. ( may be a hardware wiring issue?) It is a 4 L 2020 model with 24,000 miles. I love it when it's working. It is it has been about eight weeks in the last three months in the shop. The good part is the dealer is doing an excellent job of providing loaners. What are your thoughts about this?

Originally Posted by KK22

Update: Got car back today, sooner than expected. Everything is A-OK. Drove hard in 80 degree weather no coolant errors. So glad to have it back. Somehow my CarPlay is not connecting now, but that seems to be a recent iOS16 issue rather than Audi. Will update software and retry, I'm sure it's something I'm doing wrong.

Also, as I always do, I asked for Matrix LEDs to be unlocked. And the answer I got this time was that legally they are allowed to have them on 2023s but not on 2019s! They have requested legal approval and hope to enable them in the future. Not sure I buy that explanation, but whatever.

Hope the OPs car gets resolved soon as well.

Originally Posted by Khachatur Kocharyan

So did the replacement of the ecm fix the issue?

Originally Posted by KK22

NO! Everything replaced essentially. Coolant pump, lines, thermostat, ECM, reservoir, harnesses. Basically new cooling system. All under warranty, I suspect 10-15k worth of work. No issues since, but that better have fixed it, there was nothing else left to replace! That was about a year ago, driven hard since, even in our brutal summer.