Fuel Pump Relay

This procedure replaces the fuel pump relay in the engine compartment fuse box, which controls power to the fuel pump assembly.

Warnings

Tools required

Parts

• Fuel pump relay × 1 — Motorcraft DY-1180 or equivalent

Preparation

1. Ensure the engine is off and the key is removed from the vehicle
2. Allow engine to cool if recently operated
3. Park vehicle on level ground and engage parking brake
4. Open the hood and secure it in the open position
5. Locate the engine compartment fuse box on the driver side near the battery

Procedure

1. 1

   Disconnect battery negative terminal
   Using a 10mm socket, loosen the battery negative terminal bolt and remove the cable from the battery post. Secure the cable away from the battery to prevent accidental contact.
   Torque spec

   Battery Terminal Bolts8 Nm (6 lb-ft)
2. 2

   Remove fuse box cover
   Release the clips on both sides of the engine compartment fuse box cover by pressing or pulling outward. Lift the cover straight up to remove. The fuse/relay diagram is printed on the underside of the cover.
3. 3

   Identify fuel pump relay location
   Using the diagram on the fuse box cover, locate the fuel pump relay. On 2021-2024 F-150 3.5L EcoBoost models, the fuel pump relay is typically labeled as 'FP RELAY' or 'FUEL PUMP' and is usually a standard mini relay (20A-40A rating). Note the relay position number for reference.
   ⚠Do not confuse the fuel pump relay with the fuel pump driver module relay or PCM power relay. Installing a relay in the wrong position can cause electrical system damage.
4. 4

   Remove old fuel pump relay
   Firmly grasp the relay body and pull straight up with steady pressure. If the relay is difficult to remove, use a relay puller tool or carefully pry under the relay body with a small flathead screwdriver while pulling upward. Avoid rocking the relay side to side as this can damage the socket terminals.
5. 5

   Inspect relay socket
   Examine the relay socket for corrosion, heat damage, bent pins, or debris. The socket terminals should be clean and bright with no signs of melting or discoloration. If corrosion is present, clean with electrical contact cleaner and allow to dry. If heat damage or melted terminals are visible, the socket must be replaced professionally.
   ⚠️Heat damage or melted terminals indicate excessive current draw or poor connection. Do not simply replace the relay if damage is visible—the fuel pump circuit requires professional diagnosis to prevent fire risk.
6. 6

   Compare old and new relays
   Verify the new relay matches the old relay in physical size, pin configuration, and amperage rating. The relay should have the same number of terminals (typically 4 or 5) in the same positions. Check that the coil voltage (typically 12V) and contact rating match the original specification.
7. 7

   Install new fuel pump relay
   Optional: apply a small amount of dielectric grease to the relay pins. Align the relay pins with the socket terminals, ensuring correct orientation by matching the notch or tab on the relay base with the socket. Push the relay straight down into the socket with firm, even pressure until it is fully seated and flush with surrounding relays.
8. 8

   Reinstall fuse box cover
   Position the fuse box cover over the fuse box, ensuring it is properly aligned. Press down firmly on both sides until all clips engage with audible clicks. Verify the cover is fully seated and secure.
9. 9

   Reconnect battery negative terminal
   Clean the battery terminal and cable end if corrosion is present. Place the negative cable onto the battery post and tighten the terminal bolt to specification using a torque wrench.
   Torque spec

   Battery Terminal Bolts8 Nm (6 lb-ft)

Reassembly

1. Ensure the fuse box cover is fully seated and all clips are engaged to prevent water intrusion
2. Verify no tools or parts are left in the engine compartment
3. The vehicle may need to relearn idle parameters—some rough idle for the first few minutes of operation is normal

Verification

• Turn the ignition key to the ON position (do not start). Listen for the fuel pump to run for 2-3 seconds, then stop. This confirms the relay is functioning and energizing the fuel pump.
• Start the engine and verify it starts normally without extended cranking. The engine should start within 2-3 seconds of cranking.
• Allow the engine to idle for 2-3 minutes and verify stable operation with no stalling or hesitation.
• Turn the engine off, wait 30 seconds, then restart to verify the relay cycles properly on repeated starts.
• Check for any illuminated warning lights on the instrument cluster, particularly fuel system or powertrain-related warnings.
• If starting issues persist or the check engine light illuminates, retrieve diagnostic trouble codes to verify proper fuel pump circuit operation.

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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