Hello everyone, Rodrigo

, now I understand the problem well, inequivocally according to what you express. There is no food output from the BSI to the flashing ... therefore you need a amplifiable activation signal. I would disassemble the BSI, as you already identified, the cables, following within the BSI, first in the pin, inward ... you should reach the relay that energizes the circuit
(there may be limiting resistances of current on the road), there you must test, in the relief of the rel. It is capable of transforming this request in digital format, an analog activation (in this case there are fault codes in the BSI, or Com2000. The other is that you take it directly from the Com2000, but the analog signal of the telecoming, is only on-off, not flash, it is only within it, it also requires disassembling, identify If you have an intermittence signal in this, you take out directly from there, to an outer relief, without flash. These, look for the electro-electronic plans and implantation of the interior of the BSI (are Googlealos), you can do the fastest and faster process.