Main Relay Control

The MS S52 control module activates the main relay. This provides operating power for the control module and traction control module, fuel pump relay, secondary air pump relay/air pump, E-box cooling fan, auxiliary oil pump solenoids, purge valve, fuel injectors, VANOS solenoids, oxygen sensor heaters, air mass sensors, and idle control valve. The MS S52 maintains the ground for the main relay for a short duration after the ignition has been switched off. This allows the control module to store the adaption values and any fault codes.