L1 Good, Q1 Off = VCC * R27 / (R26+R27) (L1 is assumed to be a very low resistance)
L1 Good, Q1 On = 0V
L1 Bad, Q1 Off = VCC * R27 / (R25+R26+R27)
so for a 35V VCC
Case 1 = 1.95V
Case 2 = 0V
Case 3 = 1V
You can technically also see if Q1 has failed open or short,
The capacitor C16 would make it difficult, but technically you can also see if D3 has failed, as on switching off the transistor the voltage seen by R26 would exceed 35.7V, meaning you would measure more than 1.95V for some time
Edit: I should note, the D3 would be failing open, if it fails short, well your hopefully going to blow a fuse,