I worked out this issue by using a current mirror. Basically, an NPN pair wired up to send a very small current to the LED, not enough to light it. The mirror output would swing enough voltage that it could be sensed with a GPIO. I did it this way as I didn’t have an ADC available. Once my diags were done I turned off the current mirror so even the phantom sense wasn’t present.

If you have an ADC, you could also just measure the FET drain voltage with the driver ‘off’, which should be about (Vcc - diode Vf) of the diode, so about 2 to 2.5V for Vcc of 5V.  You will need to add a weak pull down for this to work, which you can switch off once the sensing is done.