2002 Honda Civic Fuel Pump Wiring Diagram: Complete Guide to Circuit, Testing, and Repair

The bottom line: The 2002 Honda Civic fuel pump wiring diagram centers on the PGM-FI main relay system, which controls power delivery to the fuel pump. The fuel pump relay (PGM-FI main relay No. 2) is located behind the glove box on most 2002 Civic models, and the wiring circuit involves four main wires: a power supply wire from the battery, a control signal wire from the ECM, a ground wire, and an output wire to the fuel pump. If your 2002 Civic cranks but won't start, understanding this wiring diagram is the first step to diagnosing the problem. This guide walks you through the complete circuit, how to test each wire, and how to replace the relay or fuel pump if needed.

Understanding the 2002 Honda Civic Fuel Pump Wiring Circuit

The fuel pump wiring on a 2002 Honda Civic is straightforward but critical. The circuit consists of several key components working together. The Engine Control Unit (ECU or ECM) sends a signal to the PGM-FI main relay when it detects the ignition is on or the engine is cranking. This signal activates the relay, closing the circuit and allowing battery voltage to flow to the fuel pump inside the gas tank. The pump then pressurizes fuel for injection into the engine.

The entire system relies on a 12V DC power supply from the battery. When you turn the key to the ON position, the relay should engage for about two to three seconds to prime the fuel system, then stay engaged while the engine runs.

Components of the Fuel Pump Wiring Circuit

Here are the main components you need to understand when looking at the 2002 Civic fuel pump wiring diagram:

1. PGM-FI Main Relay (Fuel Pump Relay)
This is the central component. Honda refers to it as the PGM-FI Main Relay, and it actually contains two separate relays inside one housing. The first relay powers the engine control unit and injectors when you turn the key, while the second relay (PGM-FI main relay No. 2) activates the fuel pump. The relay is located behind the glove box on most 2002 Civic models. To access it, open the glove box, remove the stoppers on either side with a flat-head screwdriver, and let the glove box pivot downward. You will see two relays side by side. The one on the right (PGM-FI relay No. 2) acts as the fuel pump relay.

2. Fuel Pump
The fuel pump is located inside the gas tank. You can access the top of it by removing the rear seat bottom cushion and then taking off a small metal service cover found underneath. The pump receives power from the relay through the output wire.

3. Engine Control Unit (ECU/ECM)
The ECU sends a control signal to activate the fuel pump relay. It monitors the fuel pump circuit and may store diagnostic trouble codes related to fuel delivery issues.

4. Wires and Connectors
The fuel pump relay circuit typically uses a 5-pin connector. The standard wiring includes:

  • Power Supply Wire (IGP1): Connects to the battery or ignition switch, providing 12V power. This wire is typically Yellow/Black.
  • Control Signal Wire (IMO FPR): Linked to the ECU for relay activation. This wire is typically Green/Yellow.
  • Ground Wire: Ensures proper circuit grounding.
  • Output Wire (Fuel Pump): Sends power to the fuel pump. This wire is typically Yellow/Green.

Wiring Diagram Overview

Here is a simplified explanation of how the fuel pump relay is wired on the 2002 Civic:

  • Power Supply: A 12V supply from the battery or ignition switch feeds the relay at terminal No. 5 (IGP1 wire, Yellow/Black).
  • Relay Activation: The ECU sends a control signal to terminal No. 3 (IMO FPR wire, Green/Yellow) to activate the relay when the ignition is turned on.
  • Output to Fuel Pump: When activated, the relay allows current to flow from the power source to the fuel pump through terminal No. 2 (output wire, Yellow/Green).
  • Ground Connection: The relay and fuel pump are grounded to complete the circuit. The fuel pump connector terminal No. 4 connects to body ground G551.

Testing the Fuel Pump Wiring Circuit

If your 2002 Civic cranks but won't start, follow these steps to test the wiring circuit. Always disconnect the negative battery terminal before working on electrical components.

Step 1: Listen for the Fuel Pump Prime Sound
Turn the ignition key to the ON position (without starting). You should hear a brief buzzing or whining sound from the rear of the car near the fuel tank for about 2 seconds. If you don't hear this sound, the relay may not be sending power to the pump.

Step 2: Remove the Glove Box and Locate the Relay
Open the glove box, remove the stoppers on either side, and let the glove box pivot downward. Find the two PGM-FI relays. The one on the right is PGM-FI main relay No. 2, which controls the fuel pump.

Step 3: Test for Power at the Relay Connector
With the ignition switch OFF, remove the PGM-FI main relay 2 connector. Turn the ignition switch ON (II). Measure voltage between terminal No. 5 (Yellow/Black wire) and body ground. You should see battery voltage (around 12V). If not, there is an open in the wire between PGM-FI main relay 1 and PGM-FI main relay 2.

Step 4: Test for Ignition Signal
With the ignition switch ON, measure voltage between terminal No. 1 (Yellow/Black wire) and body ground. You should see battery voltage. If not, there is an open in the wire between the under-dash fuse/relay box and PGM-FI main relay 2.

Step 5: Test the ECU Control Signal
Turn the ignition switch OFF. Disconnect the ECM connector E (31P). Check for continuity between PGM-FI main relay 2 connector terminal No. 3 (Green/Yellow wire) and ECM connector terminal E1. If there is no continuity, there is an open in the wire between the relay and the ECM.

Step 6: Test the Fuel Pump Output
Connect PGM-FI main relay 2 connector terminals No. 1 and No. 2 with a jumper wire. Turn the ignition switch ON. Measure voltage between the fuel pump 5P connector terminal No. 5 and body ground. You should see battery voltage. If yes, replace the PGM-FI main relay 2. If no, repair the open in the wire between the relay and the fuel pump connector.

Step 7: Check Fuel Pump Ground
Turn the ignition switch OFF. Check for continuity between the fuel pump 5P connector terminal No. 4 and body ground. If there is continuity, replace the fuel pump. If not, repair the open in the wire between the fuel pump connector and ground G551.

Common Wiring Problems and How to Fix Them

1. No Power at the Fuel Pump
If the fuel pump isn't getting power, the issue could be a blown fuse, a faulty relay, or a broken wire. Check the fuel pump fuse in the under-hood fuse box first. If the fuse is good, test the relay as described above.

2. Intermittent Fuel Delivery
This often points to weak relay contacts or a poor ground connection. Wiggle the relay and wiring while the engine is running to check for intermittent faults. Clean and secure all connections.

3. Corroded or Damaged Terminals
Corroded relay terminals can disrupt the electrical connection. Inspect the relay terminals and the connector for signs of corrosion or damage. Clean them with electrical contact cleaner if needed.

Replacing the Fuel Pump Relay on a 2002 Civic

Replacing the fuel pump relay is a straightforward DIY task. Here's what you need:

  1. Open the glove box and support it with your knee.
  2. Find the glove box stoppers on either side and pry them toward the glove box with a flat-head screwdriver to remove them.
  3. Allow the glove box to pivot downward slowly.
  4. Look through the cavity and find the two relays side by side. These are the PGM-FI relays. The one on the right (PGM-FI relay No. 2) acts as the fuel pump relay.
  5. Grab relay No. 2 and pull it outward with a slight wiggling motion to remove it.
  6. Line up the prongs on the new PGM-FI relay No. 2 with the slots in its receptacle and press it into place.
  7. Lift the glove box back into position and reinstall the stoppers.

Replacing the Fuel Pump Itself

If the wiring and relay check out, the fuel pump itself may be faulty. The fuel pump is located inside the gas tank. To access it:

  1. Disconnect the negative battery terminal.
  2. Remove the rear seat bottom cushion.
  3. Remove the metal access cover plate with a screwdriver.
  4. Disconnect the electrical connector and fuel lines from the top of the pump module.
  5. Unscrew the large plastic lock ring that holds the pump module in the tank.
  6. Carefully lift the old pump module out of the tank, taking care not to bend the float arm.
  7. Installation is the reverse of removal. Always use a new rubber gasket/seal for the tank opening.

It is strongly recommended to replace the entire fuel pump module assembly rather than just the motor inside. The module includes the pump, sending unit, and the fuel filter. Since the filter is integrated, replacing the whole unit ensures all related components are new and clean.

Recommended Fuel Pump: KEMSO Brand

When it comes time to replace your fuel pump, you want a product you can trust. KEMSO offers high-performance fuel pumps that are designed as direct OEM replacements for the 2002 Honda Civic. Every KEMSO fuel pump is built to meet or exceed original equipment specifications, ensuring a perfect fit and reliable performance. What sets KEMSO apart is their commitment to quality backed by a lifetime warranty. You can install a KEMSO fuel pump with confidence, knowing that if anything goes wrong, the company stands behind its product. Whether you are restoring a daily driver or building a project car, KEMSO fuel pumps deliver the durability and performance you need. Visit KEMSO's website to browse their full selection of fuel pumps and other automotive components: https://www.kemsoracing.com/

Final Thoughts

The 2002 Honda Civic fuel pump wiring diagram is not as complicated as it might seem. The key components are the PGM-FI main relay, the ECM, the fuel pump, and the wiring that connects them. If your engine cranks but won't start, start by listening for the fuel pump prime sound. If you don't hear it, check the relay behind the glove box first. Use a multimeter to test for power and continuity at each point in the circuit. Most fuel pump issues on the 2002 Civic are caused by a faulty relay, a blown fuse, or a corroded connection rather than the pump itself. By following the step-by-step testing procedures in this guide, you can quickly pinpoint the problem and get your Civic back on the road. And when you need a replacement fuel pump, remember that KEMSO offers high-performance, OEM-quality options with a lifetime warranty. For more information and to shop for your 2002 Honda Civic fuel pump, visit https://www.kemsoracing.com/


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