So I have gathered some more evidence related to my parasitic drain.
Through voltage-drop measurements across all fuses, I found that one particular 20 amp fuse (no. 23 in the interior fuse panel) is having a voltage drop of .6 mV between the two contact points, which, according to
this voltage drop chart, translates into 187 milliAmps.
The test was performed with all door latches in the locked position, then waiting a couple of hours to ensure all systems enter sleep mode.
According to a fuse diagram I found somewhere for my car model, the fuse in question (fuse no. 23 in interior panel) serves the following purposes:
Rain/light recognition sensor -G397-
Vehicle Electrical System Control Module -J519-
Telephone Transceiver -R36-
16-pin connector -T16-, data link connector -GX22-
I checked my car for error codes using OBDeleven, and found the following faults that may be related:
- Gateway module: Telephone Transceiver (No signal/communication)
- Telephone module: Telephone microphone (open circuit); Left audio channel for speech/telephone (open circuit); Right audio channel for speech/telephone (open circuit)
These errors have been there for a while and keep coming back periodically when cleared. My mobile phone is connected via BT directly with the Android HU, so I don't need the car's telephone function anymore. But I wonder if the above Telephone related errors could be the cause of the parasitic drain somehow. Are there perhaps some coding changes I can perform to tell the car that I don't need it's Telephone function and also not the speech control stuff?
Any suggestions appreciated!
P.S.: The aftermarket radio is not the direct source of the parasitic drain -- the drain continues even when the respective fuse is completely pulled, and there is also no measurable voltage drop at that fuse