Lexus IS Parking Brake Fault

Oh, that sucks. An unresponsive electronic parking brake on a Lexus IS? That's not exactly confidence-inspiring! It sounds like you're on the right track suspecting the motor. Have you checked the brake switch itself, just to rule out something simple? It would be a bummer to replace the caliper only to find out it was a bad connection or a faulty switch all along. Is there any unusual behavior before the complete failure? Like a noise?

Good call on the switch, I hadn't thought of that. Is there a reliable way to test the switch without just throwing parts at it? As for behaviour before the failure - nothing. I parked as usual, and the next time I tried to move the car, the handbrake wouldn't release.

Testing the switch can be tricky without the right tools. A multimeter is your friend! You could also try searching online forums for Lexus IS-specific guides. That said, a sudden and complete failure like you're describing definitely points more towards the motor in the caliper itself. Electronic parking brakes can be finicky, like a toddler refusing to eat their veggies. Given the error code (even if it's a generic one), and the sudden nature of the failure, I'd lean towards getting it properly diagnosed by a workshop. Just to be safe, of course, as it seems like it can be a vehicle safety issue.

Appreciate the advice. Took it to the shop, and you were spot on – defective electric motor in the brake calliper. 505€ lighter now, but at least it's fixed.