telephone : right hand fascia ( end of dashboard passenger side ) fuse position F3 , 5 A ( SECOND ROW, third from left to right , the other 3rd fuse viceversa is the diagnostic socket , 10 A , in case your fuse panel is mirrored ) , also check fuse F5 5A , first row down , 5th from left to right ( should be next to an empty space , or 8th fuse
Quote: Originally Posted by SMac770. You'd have to scan for DTCs. My driver's seat heater hasn't worked in a long time because the heater grid in the seat is broken, thus I have the DTC "heated seat (Z45), electrical fault in circuit". It could be something else for you, but you need to be able to scan DTCs to see what the car actually knows.
What you see at 0.4 volts is the canbus trying to detect a bulb. When you plug in a known good bulb, the canbus should detect it, and then put a full 12v on the circuit. As far as I know, there is no fuse specific to numberplate lights. If you get 0.4v, then it indicates the circuit is good.
Step 1 – Check the fuse. If your MMI doesn't start up at all, then it's probably not receiving power. The fuses that control many of the MMI modules are located in a compartment in the left side of your trunk. Pry open the side panel in the trunk and inspect the fuses. Use a multimeter to check the fuses and ensure one of them isn't burned out.
The normal fuse for the heated seat is column 2, fuse 5, 30A. A 4mm² line to the J519. Depending on where you mount all this, you could run a 4mm² line from that fuse 5 position (doubt there's an output wire there if you didn't have heated seats stock) to a relay and control it with a wire tapped off the 12v socket wire.
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