If the power door lock switch does not operate electrically, the only way to lock the door(s) is with the mechanical key from the outside key hole.
You can lock the doors without the outside key hole as follows:
1. Open the door.
2. Insert the key into the emergency door lock hole and turn the key horizontally to lock.
3. Close the door securely.
Kia Cee'd JD Service Manual: Yaw-rate and Lateral G Sensor Repair procedures
Removal
1.
Turn ignition switch OFF and disconnect the negative (-) battery cable.
2.
Pull the passenger seat towards the front till the end.
3.
Disconnect the yaw rate & lateral G sensor connector ...
Kia Cee'd JD Service Manual: Intake Manifold Repair procedures
Removal and Installation
1.
Remove the engine cover.
2.
Disconnect the battery negative terminal.
3.
Remove the air cleaner assembly.
(Refer to Intake And Exhaust System-"Air Cleaner")
...