Background
This procedure was written for a 2000 Explorer Sport with SOHC V6. The wiring should be very similar for 1998 thru 2000 models.
The energizing of the Fuel Pump Relay is controlled by the PCM. If the PCM does not have power then neither will the Fuel Pump Relay.
The Inertia Fuel Shutoff (IFS) switch (located next to the front passenger kick panel) prevents the fuel pump from receiving power after a collision.
The main power to the Fuel Pump Relay comes from Fuse 9 (20 amps) in the Battery Junction Box. The PCM energizes the Fuel Pump Relay for a few seconds when the Ignition Switch is turned to On and when the Ignition Switch is turned to Start. Two persons may be required to accomplish some of the steps. One to turn the ignition key and the other to perform a voltage measurement.
The Haynes Repair Manual incorrectly states that the PCM will energize the fuel pump relay as long as pulses from the Camshaft Position Sensor (CMP) indicate that the crankshaft is rotating. Actually, the PCM monitors pulses from the Crankshaft Position Sensor to determine if the crankshaft is rotating. The PCM uses the pulses from the Camshaft Position Sensor to determine if cylinder 1 is on the compression or exhaust stroke.
Procedure
1. Turn Ignition Switch to On
Does "CHECK ENGINE" illuminate?
Yes: Go to next numbered step
No: Perform the
PCM Power Procedure
2. Do you hear the Fuel Pump run for a few seconds when Ignition Switch is switched to On?
Yes: If desired perform the
Fuel pressure test procedure
No: Go to next numbered step
3. This check isolates between a failure in the power path to the fuel pump and the PCM controlled energizing of the fuel pump relay.
a. Remove the fuel pump relay in the Battery Junction Box
b. Install a jumper between relay socket contacts 3 and 5.
c. Switch ignition to ON. Does fuel pump should run continuously?
Yes: Failure is due to fuel pump relay or PCM control of relay. Go to step 9.
No: Failure is due to bad fuel pump, power path to fuel pump or power path from fuel pump to chassis ground. Go to next numbered step
4. Is Inertia Fuel Shutoff (IFS) switch set (button pushed in)?
Yes: Go to next numbered step
No: Depress IFS reset button and repeat step 2 above
5. Is Fuse 9 (20 amps) in the Battery Junction Box good?
Yes: Go to next numbered step
No: Replace fuse and repeat step 2 above
6. Disconnect Fuel Pump/Sending Unit electrical connector (C311) located on the inside of the left frame rail in front of Fuel Tank.
7. Is the resistance from female C311, Pin 7 (black wire) to ground less than 1 ohm?
Yes: Go to next numbered step
No: Clean/tighten the ground connection (G204) located under left side of Instrument Panel behind Kick Panel. Reconnect electrical connector and repeat step 2 above.
8. Is the voltage at female C311, Pin 6 (pink/black wire) battery voltage when Ignition Switch is switched to ON?
Yes: Remove/replace fuel pump
No: Check wiring for breaks from connector to Inertia Fuel Shutoff switch
9. Remove jumper and Swap Fuel Pump Relay in the Battery Junction Box with the Rear Wiper Down Relay in the Battery Junction Box and repeat step 2 above
10. Make sure PCM connector bolt is snug (do not overtighten).
11. Remove PCM connector and see if pin 80 is pushed back.