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.
Main Relay (Computer/Fuel System): Description and Operation
2004 Honda S2000 L4-2.2LSECTION Description and Operation
PGM-FI Main Relay
The PGM-FI relay contains two separate relays. One is energized whenever the ignition is ON (II), which supplies battery voltage to the ECM, power to the injectors, and power for the second relay. The second relay is energized to supply power to the fuel pump for 2 seconds when the ignition switch is ON (II), and when the engine is running.
The PGM-FI relay contains two separate relays. One is energized whenever the ignition is ON (II), which supplies battery voltage to the ECM, power to the injectors, and power for the second relay. The second relay is energized to supply power to the fuel pump for 2 seconds when the ignition switch is ON (II), and when the engine is running.
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.