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BigBob, Shop manager/Service Manager
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Honda civic: fuel pump relay location and wiring diagram

Customer Question

honda civic 05 main relay , and fuel pump relay location and wiring diagram
Submitted: 7 years ago.
Category: Honda
Expert:  BigBob replied 7 years ago.
Greetings,


Fuel Supply System

Fuel Cut-off Control
During deceleration with the throttle valve closed, current to the injectors is cut off to improve fuel economy at engine speeds over 850 rpm . Fuel cut-off action also occurs when engine speed exceeds 6,900 rpm , regardless of the position of the throttle valve, to protect the engine from over-revving. With the A/T model, when the vehicle is stopped in P or N, the PCM cuts the fuel at engine speeds over 5,000 rpm .

FUEL PUMP Control
When the ignition is turned on, the ECM/PCM grounds the PGM-FI main relay which feeds current to the fuel pump for 2 seconds to pressurize the fuel system. With the engine running, the ECM/PCM grounds the PGM-FI main relay and feeds current to the fuel pump. When the engine is not running and the ignition is on, the ECM/PCM cuts ground to the PGM-FI main relay which cuts current to the fuel pump.

PGM-FI Main Relay 1 and 2
The PGM-FI relay consists of two separate relays. PGM-FI main relay 1 is energized whenever the ignition switch is ON (II) which supplies battery voltage to ECM/PCM, power to the injectors, and power for PGM-FI main relay 2. PGM-FI main relay 2 is energized to supply power to the fuel pump for 2 seconds when the ignition switch is turned ON (II), and when the engine is running.

PGM-FI Main Relay 1 and 2
The PGM-FI relay consists of two separate relays. PGM-FI main relay 1 is energized whenever the ignition switch is ON (II) which supplies battery voltage to ECM/PCM, power to the injectors, and power for PGM-FI main relay 2. PGM-FI main relay 2 is energized to supply power to the fuel pump for 2 seconds when the ignition switch is turned ON (II), and when the engine is running.
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I will upload the wiring diagram if you let me know which model, hx,ex,dx?

let me know if I can help further.

Good luck,
Bob

my information is not free, I have to pay for it, please don’t forget to accept, I don’t get paid until you do

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