I can not get the doors to lock, or the trunk to unlock with the key manually.
What is your question?
Trunk button near power windows, the key itself, or the remote on the key, wont open trunk. Nor can I lock the doors. Works fine in the ignition to start the car.
RepairPal Certified shops can diagnose and repair your 1996 Mercedes-Benz C280. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.