Lexus IS Mirror Heating Failure

Alright, I've got a head-scratcher. My 2010 Lexus IS with a gasoline engine has a mirror heating malfunction. Both side mirrors refuse to defrost, and the car's throwing an error code related to the heating circuit. I've checked the fuses – all good. I am suspecting a defective connection, but winter is coming, and I don't have enough time for a detailed investigation.

4 comment(s)

I had a similar issue on my IS (not sure about the year). Check the wiring harness where it enters the door. It's a common spot for wires to get pinched or broken over time, especially with the mirror's folding mechanism. Also check the heater element itself. Has the resistance been measured yet?

Good shout about the wiring harness! I will check that. About the resistance check you mentioned: Could you please provide more detail?

Yep, the wiring harness is the most probable root cause. I was also skeptical at first, but my mechanic found it there. As for the resistance of the heating element: If the wiring is fine, it's likely the element itself is kaput. Consider a visit to the workshop to be on the safe side.

Thanks a lot for the input! It really helped. I took it to my mechanic who was able to confirm that the wiring harness was indeed damaged as you suspected. He replaced it. It cost me around 95€, and the mirror heating is now functioning flawlessly!

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