Phaeton GP3 ADR Emergency Shut-off Switch (F317) Test Instructions

Hello everyone in the forum community,

My 2010 Phaeton is currently in the workshop (Bosch service) due to a faulty ACC (Adaptive Cruise Control) system. The diagnosis so far indicates that the ADR release switch in the brake booster is defective. Unfortunately, this switch is not available as a separate part, so the entire brake booster needs to be replaced. The workshop doesn't have a testing procedure for the switch, but they would like to test the switch first to rule out other defects before replacing it.

Can anyone in this forum help me with a testing procedure for this component?

Thank you very much and best regards!