It's one of the fuses on base unit in the computer box as you mentioned. you need an Allen wrench to open the box, there are 4 10 Amp fuses (3 if no ASR option). F1 is the first one counting from left if you stand in front of the car.

Can't remember what other fuses do, you might also pull out them and check.

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99 BMW 540i 6-speed 110K Km
03 SAAB 9-5 wagon 80K Km
92 400E (Sold) 245K km
Still missing the days with the Benz, it kept me busy.