The negative cable, which is normally connected to the negative pole of the battery, is fastened to the crankcase. From here, the cable branches off and splits up within the electrical system to carry the ground connection to the different elements in the system.

The image shows the ground connection on left side of the engine crankcase.
The battery charging circuit and power distribution
Electrical power for lighting and signalling devicesPassive key
Introduction
The passive key (1) is used when the active key is not working correctly or
is not available.
The passive key works as a transponder, and must therefore be placed physically
onto the antenna to work.
The mechanical part (2) of the key is used to open the seat or the tank plug ...
Accelerator position sensor (throttle grip)
Introduction
An accelerator position sensor (aps) is mounted on the throttle body of the
diavel, which measures the degree of aperture
of the throttle grip.
The throttle grip is connected to the sensor via two metal cables
The sensor transmits information to the ecu relative to the "torque ...
Overhaul of cylinder head components
Cylinder heads
Remove any carbon deposits from the combustion chamber and its ducts.
Remove any scale from the coolant ducts.
Check for cracking and inspect the sealing surfaces for scoring, ridges or other
damage.
Check that the cylinder barrel mating surfaces of the cylinder head are ...