Hello,
I'm experiencing an issue with the mirror heating feature on my 2014 Cayenne v6 Platinum. When I scan for codes, I get code 0398 (Heated exterior mirror, electrical fault - electrical fault in circuit).

In the live data, whether in accessories mode or with the engine running and the vehicle parked, I get: mirror heating output: 0%, mirror heating: off, even when I press the defroster button.
However, if the vehicle is running/driving the live data shows mirror heating output at 100% and mirror heating as “on” when I press the defroster button. When I switch it off, the heating output drops to 0% and mirror heating shows as “off,” so it seems to work while the vehicle is moving. But to be honest, I don’t feel any heat on the mirrors. The rear window defroster works without any issues.

Does anyone know what could be causing this issue?

 

Just got a 2013 958 GTS… seeing the same code. Following…

 

Any solutions to this problem? I have the same code popping up.

 

Not yet, I just ordered a multimeter. I’m going to run a few tests. If you have one, locate the front door electronics fuse, start the engine, and press the defroster button. Place the multimeter probes on the fuse and check if you get a reading.

If you see numbers, remove the mirror glass and disconnect the heater connections (they are in the middle; the dimmer connections are on the edges). Then, place the probes on the socket with the defroster on and the engine running to see if you get a reading. If you do, switch the multimeter to resistance mode, disconnect the mirror from power, and test the resistance of the heating element.

I saw that PIWIS has an option to activate the heater, but I haven’t had time to try it.

If the mirror heater is damaged, you have two options:

1. OEM replacement – Expensive but retains all functions.

2. Aliexpress replacement – Cheap but loses the auto-dimming function.

Alternatively, you could buy a generic heating pad that fits the mirror, remove the current one, and stick the new pad in its place. This way, you’ll keep the auto-dimming function.

Also, cayenne’s mirror heater is pretty useless since it only turns on when the outside temperature is below 46°F.

 

@lp2885 Did you make any progress on this? I've had this problem since I bought the car 6 years ago.

 

Heating pad is damaged on both mirrors (common issue), there are two options, aliexpress ones with heating but without dimming or oem, which is very expensive. I ordered aliexpress ones, but haven’t installed yet.

 

Got it. Thanks for the update. Good luck with it.