Idle Control System (ZWD 5)
Idle control on the S62 engine is carried out using the ZWD 5 idle control valve. The valve features a second air supply system that functions independently from the throttle control system. The idle valve draws in metered air from the intake plenum and it is connected to both sets of throttle valves though an interconnected pipe.
The valve receives power from the main relay and the open and close windings are controlled by the MS S52 control module. Without power, the valve is open approximately 30%.
Under certain conditions, the idle control valve can be opened by the control module to provide air flow for emergency (limp home) operation.