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940 L4-2.3L SOHC VIN 88 B230F (1992)

Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Description and Operation > Fuel Injection

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Engine Control Module: Description and Operation
Fuel Injection

Bosch

Fuel Injection System Components

PURPOSE

The Electronic Control Unit (ECU), located in passenger side kick panel, has a microprocessor that receives signals from various input devices
regarding engine operating conditions. This information will be evaluated in relation to pre-programmed values and it calculates the optimal
injector frequency (opening duration) to provide optimal air/fuel mixture, performance, driveability and emissions output.

Input devices (the ECU receives):

^ Battery voltage.
^ Ignition switch signal.
^ Lambda sond signal (exhaust gas oxygen content).
^ RPM signal from the ignition control unit.
^ Speedometer signal.
^ Crankshaft position signal from the ignition control unit.
^ Knock signal from the ignition control unit.
^ Coolant temperature signal.
^ Air mass meter signal.
^ Gear selector signal (automatic transmission only).
^ Throttle position signal.
^ A/C switch signal.
^ A/C pressure sensor signal.

Output devices (The ECU controls):

^ The voltage for the system by grounding the system relay.
^ Suppressor relay by controlling the system relay.
^ Fuel injector ground.
^ Cold start injector ground.
^ Idle valve.
^ Load signal to the ignition system control unit (ignition ECU input device).
^ Shift indicator light (manual trans. only).

Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Description and Operation > Fuel Injection

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