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Home >> Volvo >> 2005 >> S60 L5-2.4L Turbo VIN 54 B5244T5 >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Relays and Modules - Computers and Control Systems >> Main Relay (Computer/Fuel System) >> Description and Operation
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Main Relay (Computer/Fuel System): Description and Operation



Main Relay (System Relay)







The function of the main relay (system relay) is to supply certain components with voltage.

The relay is mechanical and has a closing function. In the rest position the circuit in the relay is open.

The main relay terminals (#30 and #86) are supplied with voltage by the battery. When the ignition key has been turned and the Engine Control Module (ECM) is powered, the terminal (#85) on the main relay is grounded by the Engine Control Module (ECM).

When the terminal (#85) is grounded, the relay is activated and a number of components are powered via the relay terminal (#87).

The engine control module (ECM) can diagnose the main relay.

The main relay is in the relay/fusebox in the engine compartment.
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