Sea-doo 2001 GS, Shop Manual

Page: 211 / 456

Section 06 FUEL SYSTEM
Subsection 05 (FUEL INJECTION)
06-05-4
SMR2000-018_06_05A.FM
ELECTRONIC MANAGEMENT
Electronic Control Unit (ECU)
The electronic fuel injection is equipped with a
Bosch Electronic Control Unit (ECU).
ELECTRONIC CONTROL UNIT (ECU)
The ECU is mounted behind the MPEM in the
front of the watercraft, in a watertight box.
The ECU controls the following functions:
Basic Operating Function
1. Electronic Fuel Injection
The ECU receives the signals from 5 sensors which
indicate engine operating conditions at milli-second
intervals.
– Throttle Position Sensor (TPS)
– Crankshaft Position Sensor (CPS)
– Air Temperature Sensor (ATS)
– Water Temperature Sensor (WTS)
– Air Pressure Sensor (APS)
These signals are used by the ECU to determine
the injection duration required for optimum air-fuel
ratio.
2. Ignition Timing
The ECU is programmed with data for optimum
ignition timing under all operating conditions. Us-
ing data provided by the sensors, the ECU controls
the ignition timing for optimum engine operation.
3. Maximum Engine Speed
The ECU limits the maximum allowable engine
speed. The RPM rev limiter is set at 7200 ± 50
RPM.
4. Fail-Safe Function
In the event of a sensor malfunction, the ECU will
use a default operating mode to ensure driveability
to shore. A message may be displayed on the Info
Center to inform the operator.
5. Diagnostic Mode
The ECU is able to detect malfunctions in the sen-
sor network. The malfunction is recorded in the
memory of the ECU. The memory of the ECU can
be checked using the MPEM programmer tool.
MPEM
(Multi-Purpose Electronic Module)
The MPEM is also used with the Rotax Fuel Injec-
tion system.
MPEM
It is responsible of the following electrical func-
tions:
– interpreting information
– distributing information
– start/stop function
– timer
– vehicle hours
– Digitally Encoded Security System (DESS).
The MPEM has a special safety feature to limit
engine revolutions when the battery voltage is too
low.
For example, when the battery voltage reaches
8.9 volts for at least 30 seconds, engine revolu-
tions are limited to 4480 RPM.
When voltage reaches 7 volts for at least 30 sec-
onds, the engine is automatically shut off by the
MPEM.
F07F0BA
F07H0BA
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