volvo Workshop Repair Guides

Volvo Workshop Service and Repair Manuals

System Relay|Page 365 > < Diagram Information and Instructions|Page 362
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Main Relay (Computer/Fuel System): Description and Operation
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.

 

System Relay|Page 365 > < Diagram Information and Instructions|Page 362