Lotus Elise Service Notes page 455

Lotus Service Notes
Section PH
PH.3 - VACUUM CONTROL SYSTEM
Engine vacuum, tapped from the intake plenum, is used to operate the screen, footweli and re-circ. flaps,
and the water valve. The vacuum supply to each of the actuators is controlled by separate solenoid valves
mounted on a bracket above the pedal box, with the solenoids switched by the climate distribution control. In
order to maintain flap operation during periods of high manifold pressure or after engine switch off, a vacuum
reservoir with integral non-return valve is mounted within the RH rear wheelarch, accessible after removal of
the wheelarch liner. The sector rack and pinion temperature control is equipped with an electrical micro-switch,
closed at the full cold position to operate a solenoid valve and supply the water valve actuator. Note that the
default position of the flaps (no electrical power or vacuum supply) is; screen flap open, footweli flap closed,
fresh air intake open. The water valve default is open.
The vacuum pipes from reservoir to solenoid valves, and from water valve soleinoid valve to actuator,
run along the outside of the RH chassis sideraii. Note that the vacuum supply to the three identical solenoid
valves is to the central of the two ports on each valve. The wiring harness to each of the three identical
solenoid valves is colour coded with tape, with yellow (water valve) outermost, red (re-circ.) central, and blue
(footweli) innermost. The fourth solenoid is of a different design to operate the screen flap.
Vacuum Schematic
2000 / 04
Page 9