Sub panel question

[sstock]

Was in a discussion with a buddy and was wondering what the correct answer is. He has a house with a 200 amp main panel and a detached garage with a lugged 100amp sub panel, all built around 1990. He recently added a circuit in his detached garage and seen that there was a bonding screw in the sub panel and it was fed from the main panel with three wires (2 hots and a neutral). There was a separate ground rod at the detached garage and a copper wire that runs from the grounding rod to the ground lug in the panel. Also the grounds and neutrals are separated in the sub panel. Should he remove the bonding screw or leave it?
Thanks,
Steve

 

[Terry D]

3-wire feeds to detached buildings were allowed up until the 2008 NEC change. as long as there were no metallic pathways bonding the sub panel to the main panel. . Yes, the bonding screw needs to remain installed

 

[sstock]

Thank you sir