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Home >> Volvo >> 1992 >> 240 L4-2.3L SOHC VIN 88 B230F >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Relays and Modules - Computers and Control Systems >> Main Relay (Computer/Fuel System) >> Description and Operation >> System Relay
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System Relay

Sent by the fuel injection ECU:

PURPOSE
The system relay (located in passenger side kick panel) provides current to the fuel pumps, idle air valve, fuel injectors, cold start injector, mass air flow sensor, oxygen sensor pre-heating resistor and to other ECU controlled functions or components.

OPERATION
The fuel injection ECU controls the relay ground connection. When ground is supplied, the system relay is activated and currant can flow to all the related components. If the ground connection is interrupted, no current can reach the components.
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