Corolla Seat Heater Failure

Defective seat heating elements are unfortunately common. The error code likely indicates an open circuit or short to ground within the heating element, or a thermal sensor issue. Have you inspected the wiring harness and connector for damage, corrosion, or loose connections? Also, the ground connection for the seat heating circuit is paramount.

Thanks for the quick reply! I did a quick visual inspection of the wiring and didn't see anything obvious, but I haven't checked the ground. Where is the ground connection usually located? If it IS the heating element, is it worth repairing, or am I better off replacing the whole seat cushion?

An unstable ground connection is known to trigger those symptoms. In most Toyotas, the ground connection for the seat is typically located on the body, beneath the seat, or along the B-pillar. As for repair versus replacement, given the labor involved and the potential for further complications, replacement of the heating element, if confirmed defective via resistance testing, is generally more prudent. Diagnosing this at home is challenging, so proceed with caution. A visit to a qualified workshop may be warranted.

Okay, that's what I was afraid of. I'll check the grounds first, but looks like I'll bite the bullet and take it to the workshop. They quoted me around 390€ for the heating repair, so at least I have an idea of the cost. Thanks for confirming my suspicions!