3.8l FI. Why is there no power from fuel pump relay in trunk to fuel pump?

Check fuses first. With a volt meter check for power to the fuel pump relay and thru the relay. Check for power at the fuel pump connector in the trunk. If you have power to the pump replace the pump.

Check your main fuel relay.



Fuel Supply System


PGM-FI Main Relay


Description


This PGM-FI main relay is located behind the dashboard


lower cover. The PGM-FI main relay actually contains


two individual relays. One relay is energized whenever


the ignition is on. It supplies battery voltage to the PCM,


power to the fuel injectors, and power for the second


relay. The second relay is energized for 2 seconds when


the ignition is switched on, and when the engine is running.


It supplies power to the fuel pump.


PGM-FI


MAIN RELAY



FUEL


PUMP


RELAY


Relay Testing


NOTE: If the engine starts and continues to run, the PGMFI


main relay is OK.


1. Remove the PGM-FI main relay.


2. Attach the battery positive terminal to the No. 3*


terminal and the battery negative terminal to the


No. 2* terminal of the PGM-FI main relay. Then


check for continuity between the No. 5* terminal and


No. 2 terminal of the PGM-FI main relay.


• If there is continuity, go on to step 3.


• If there is no continuity, replace the relay and


retest.



*: 8P CONNECTOR


To FUEL PUMP


3. Attach the battery positive terminal to the No. 4 terminal


and the battery negative terminal to the No.


7* terminal of the PGM-FI main relay. Then check


that there is continuity between the No. 3 terminal


and No. 1 terminal of the PGM-FI main relay.


• If there is continuity, go on to step 4.


• If there is no continuity, replace the relay and


retest.


4. Attach the battery positive terminal to the No. 1 terminal


and battery negative terminal to the No. 2*


terminal of the PGM-FI main relay. Then check that


there is continuity between the No. 5* terminal and


No. 2 terminal of the PGM-FI main relay.


• If there is continuity, the relay is OK;


If the fuel pump still does not work, go to Harness


Testing on the next page.


• If there is no continuity, replace the relay and


retest.



To PCM CONNECTOR


TERMINAL A4


To ST. SWITCH


To GROUND


To IGN. 1 To BAT


To PCM


CONNECTOR TERMINALS


A13 and B1


FUEL PUMP


RESISTOR


FUEL PUMP

• Basic Fuel System Diagnosis
• Fuel Lines And Fittings
• Fuel Tank
• Programmable Multi-port Fuel Injection Pgm-fi System
• • Fuel Charging Assembly
  • Fuel Injector S
  • Fuel Pressure Regulator
  • Fuel Pump
  • General Information
  • Pgm-fi Main Relay
  • Relieving Fuel System Pressure
  • Throttle Body

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• PGM-FI MAIN RELAY

Acura Coupes and Sedans 1994-2000 Repair Information

PGM-FI Main Relay

Print
This relay is located behind the dashboard's lower cover. It consists of two individual relays. One is energized whenever the ignition is ON , thus supplying battery voltage to the Powertrain Control Module (PCM). This relay also supplies voltage to the fuel injectors, and power to the second relay. The second relay is energized for two seconds, when the engine is turned ON , to power the fuel pump.
See Figure 1

Fig. Fig. 1: Schematic of the PGM-FI relay
Testing
If the engine starts and continues to run, the PGM-FI relay is working and does not need to be replaced.
See Figure 2

Fig. Fig. 2: PGM-FI relay terminal numbers

1. Remove the relay.
2. Apply battery voltage to the number three terminal.
3. Ground the number two terminal.
4. Check for continuity between terminals five and two.
5. If continuity is detected, proceed to the step 7.
6. If there is no continuity, replace the relay.
7. Connect the number four terminal to the positive side of the battery.
8. Ground the number two terminal of the relay.
9. Check for continuity between the number five terminal and the number two terminal of the relay.
10. If there is continuity, the relay checks out "OK". If the fuel pump still does not work, test the harness.
11. If there is no continuity, replace the relay and retest.

PGM-FI main relay 1 (FI MAIN) is energized whenever the ignition switch is ON (II) to supply battery voltage to the ECM/PCM, power to the injectors, and power for PGM-FI main relay 2 (FUEL PUMP). PGM-FI main relay 2 (FUEL PUMP) 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 cranking or running.

Check the fuel pump reset which is usually on the drivers side in the trunk under the mat. By-pass it and see if the fuel pump will start.They can become corroded and may be your problem. Fuel pump relay should be under the hood and marked as FI or Fpump etc. New Answer: the relay is in front of the shifter under the dash if you get the panels off (shifter cover , lower center panel and left center panel you can see it and the PCM power relay if you lay on passenger floor and look to rear of center area.

look in the trunk, your vehicle is most likely equiped with a fuel pump reset switch.. if you look in the manual, or have access to a manual it will tell you exactly where its at, most of the time they are on the driver side of the trunk behind by fender well.

I suspect the at this point, the main relay is defective. This relay controls power to fuel and spark circuits.

The PGM-FI Main Relay is actually comprised of two individual internal relays. When the ignition switch is initially turned ON , the Powertrain Control Module (PCM) supplies ground to the PGM-FI Main Relay. This ground triggers one of the PGM-FI internal relays that sends battery voltage to the fuel pump for two seconds to pressurize the fuel system.
When the engine is running the PCM supplies a continuous ground to the PGM-FI Main Relay. The supplied ground keeps the relay in the "closed" position providing electrical current to the fuel pump, keeping the fuel loop pressurized while the engine runs.
If the engine is not running with the ignition on, the PCM cuts the ground to the PGM-FI Main Relay, causing the relay to "open" and stop the electric current flow to the fuel pump. As mentioned previously, if the engine is not running, the PCM will only supply ground to the PGM-FI Main Relay for two seconds when the ignition switch is initially switched to the ON position.
The PGM-FI Main Relay also supplies electrical power to the Idle Air Control (IAC) Valve and to the fuel injectors.

TESTING


If the engine starts and continues to run, the PGM-FI Main Relay is working and does not need to be replaced.

1. Locate and remove the relay.

On some models of the Civic and Civic del Sol it is located to the left of the steering column under the dash. Many later models position it either near the passenger right side kick panel under the dash or by the driver left side kick panel up under the dash.

1. Attach the battery positive terminal to the No. 2 terminal.
2. And the battery negative terminal to the No. 1 terminal.
3. Check for continuity between terminal No. 5 and 4.
4. If there is no continuity, replace the relay and retest

fuel pump shut off swiches are normally in the trunk refer to your manual to find out if you have one or not.

sounds like the fuel pump relay is stuck on. find the relay and replace it. hope this helps mike

hi tony, i had that same problem come through my shop! i eventualy (hours) found the burnt wire in its clear plastic connector in trunk, above backseat headrest. (top and back of trunk). i hope this helps, so you dont have to do what i did...LOL good luck, marty