Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSVOLVO1991240 L4-2.3L SOHC VIN 88 B230FREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSMAIN RELAY (COMPUTER/FUEL SYSTEM)DESCRIPTION AND OPERATIONSYSTEM RELAY
1991 Volvo 240 L4-2.3L SOHC VIN 88 B230F
System Relay
1991 Volvo 240 L4-2.3L SOHC VIN 88 B230FSECTION System Relay
Sent by the fuel injection ECU:
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.
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.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.