Connectors, Disconnecting

Before disconnecting a connector, always make sure that the ignition is switched off and the vehicle key or other start authorization systems (such as a smartphone) are outside of the vehicle interior. This will prevent the vehicle from switching on unintentionally. Also, this can result in unintended DTC memory entries that must be cleared after the repair.
Perform the electrostatic discharge right before disconnecting a connector, for this, briefly touch the door striker.
Do not touch open contact pins with hands.
When connecting a connector, make sure the locking mechanism on the connector is latched correctly. Pull on it briefly to check.