Lotus Elise S1 Service Notes page 249

Lotus Service Notes Section EMN
Before removing an ECM, first disconnect the battery earth lead before pressing the retaining barb and
unplugging the harness connector(s). On standard cars, the MAP sensor is contained within the ECM body,
with the sensor hose connecting to a spigot on the underside of the unit. On pre 'boot box' cars, release the
three screws securing the ECM to the side panel, and withdraw the unit. On post Sept. '98 'bootbox' cars, the
ECM is mounted at the rear of the engine bay, standard modules fixed to the bootbox front wall, and W C
module using a steel mounting bracket. To release the W C module, undo the clamp top bolt, the second ECM
top fixing, and lift out the ECM.
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MAP sensor hose
EMN,5 - PEIAY MODULE
The MEMS relay module is single unit serviced only as one component. The unit incorportates the
following relays:
Main Relay; Supplies current to the ECM when the ignition is switched on. When the ignition is switched
off, the ECM will keep the main relay energised for a short period whilst the IAC valve is driven to its
power down position, ready for the next engine start.
Fuel P u m p Relay; Energised by the ECM for a 3 second period each time the ignition is switched on.
Continuously fed during engine cranking and while the engine is running.
Starter Relay; Energised by the cranking output from the ignition switch. Supplies current to the starter
motor solenoid.
Oxygen Sensor Heater Relay; Energised by the ECM to supply current to the oxygen sensor heating
element.
The unit is mounted adjacent to the engine management ECM, either at the left hand side of the rear
luggage compartment on pre 'bootbox' cars, or, on later cars, at the rear of the engine bay on a tongue fixed to
the rear subframe.
If any of the above functions are faulty, the relay module should be replaced: Pull the module off its
mounting tongue, and release the two harness connector blocks (press the retaining clips). On re-assembly,
ensure the connector blocks are fully engaged by the retaining clips.
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