Ion Current Combustion Monitoring
In the S65, the ion current electronic system is integrated into each ignition coil and the ion current control devices are not required.
For the purposes of smoothing the voltage and electromagnetic compatibility, an "ignition suppression capacitor" is installed in the wiring harness of each cylinder bank (in the S85 this is in the ion current control device). This is electrically connected using terminal 87 and the vehicle earth.
If the ignition suppression capacitor is defective, this can lead to faults in the communications and/or audio electronics when the engine is running.
For design reasons, the firing order 1-5-4-8-7-2-6-3 is used in the S65, instead of the firing order 1-5-4-8-6-3-7-2 more commonly employed in BMW V8 engines.