System Relay
Need a step-by-step guide?
Get an AI-powered repair guide with parts lists, cost estimates, and clear instructions for your 1991 Volvo.
PURPOSE
The [1][2]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 [1][2]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.