2002 Acura RL Fuel Pump Relay Location: The Complete Guide to Finding, Testing, and Replacing It

The bottom line: The fuel pump relay on a 2002 Acura RL is located in the trunk, specifically behind the back carpet on the rear of the seat, near the fuel pump access panel . If your 2002 Acura RL cranks but won't start, or if it stalls unexpectedly, the fuel pump relay is often the first component you should check .

Understanding the Fuel Pump Relay in Your 2002 Acura RL

The fuel pump relay is a small electrical switch that controls the power supply to the fuel pump . When you turn the ignition key to the ON position, the relay receives a signal from the Powertrain Control Module (PCM) and closes its internal contacts, allowing battery voltage to flow to the fuel pump . The pump then pressurizes the fuel system so the engine can start. Once the engine is running, the relay keeps the pump powered as long as the engine is running.

Without a properly working fuel pump relay, the fuel pump never gets the signal to turn on. This means no fuel reaches the engine, and your car will not start, even though the starter motor cranks the engine just fine .

Symptoms of a Bad Fuel Pump Relay

If your 2002 Acura RL has a failing fuel pump relay, you will likely notice one or more of the following symptoms:

  1. Engine cranks but does not start. This is the most common symptom. You turn the key, the starter motor spins the engine, but the engine never fires up .
  2. Engine stalls while driving. The relay may fail intermittently, cutting power to the fuel pump while the car is moving. The engine will die suddenly, and you may have to wait a few minutes before it will restart .
  3. Long crank time. The relay may be slow to close its contacts. You might have to hold the key in the START position for several seconds before the engine catches.
  4. No fuel pump hum. When you turn the ignition key to the ON position (without starting the engine), you should hear a brief humming sound from the rear of the car for about two seconds. That is the fuel pump priming. If you hear nothing, the relay or the pump itself could be faulty .

Where Is the Fuel Pump Relay Located on a 2002 Acura RL?

On the 2002 Acura RL (first generation, model code KA9), the fuel pump relay is not under the hood. It is located in front of the trunk, behind the back carpet, near the fuel pump access panel . Here is how to find it:

  1. Open the trunk.
  2. Remove the carpet and trim covering the rear bulkhead (the panel that separates the trunk from the rear seat).
  3. Look for a small, rectangular electrical relay mounted near the fuel pump access panel. It is often next to a gray, 20-pin connector and a gray, 10-pin sub-harness connector .
  4. The relay may be labeled or have a wiring diagram printed on its side.

For reference, the PGM-FI main relay (which also controls the fuel pump on some Honda/Acura models) is located under the dashboard on the driver's side, but the dedicated fuel pump relay on the 3.5RL is in the trunk .

How to Test the Fuel Pump Relay

Testing the fuel pump relay requires a digital multimeter (DMM) and a 12-volt power source, such as a small battery or a fused jumper wire. Follow these steps:

Step 1: Remove the relay. Carefully pull the fuel pump relay straight out of its socket. Do not pry on the plastic housing.

Step 2: Identify the terminals. Look at the relay's schematic, which is usually printed on the side. You need to identify the coil terminals (the control circuit) and the load circuit terminals (the switch contacts) .

Step 3: Check the coil resistance. Set your multimeter to ohms (Ω). Measure the resistance across the coil terminals. A good relay will typically show a reading between 50 and 120 ohms . If you see infinite resistance (OL), the coil is open and the relay is defective.

Step 4: Check the switch operation. Set your multimeter to continuity (beep mode). Test between the load circuit terminals. In its normal state (relay not energized), a normally open (NO) relay should show no continuity (no beep). Now, apply 12 volts and ground to the coil terminals. You should hear a distinct click as the relay energizes. With the coil energized, test the load terminals again. This time, you should get continuity (beep) . If the relay does not click or does not show continuity when energized, replace it.

What to Do If the Relay Tests Good

If the fuel pump relay passes the bench test, the problem may lie elsewhere. The official Acura service manual provides a detailed troubleshooting flowchart for the 2002 Acura RL . Here are the next steps:

Check the fuel pump resistor. The fuel pump resistor is located in the left corner of the trunk . A faulty resistor can prevent the fuel pump from running at low speed, causing a no-start condition. To test it, disconnect the 2-pin connector from the resistor. Turn the ignition ON and within two seconds, measure voltage between the resistor connector terminal No. 2 (Yellow wire) and ground. If battery voltage is present for only two seconds, the resistor may be bad. You can bypass the resistor temporarily by using a fused jumper wire to connect terminals No. 1 (Black/Yellow) and No. 2 (Yellow) at the resistor connector. If the engine starts with the jumper in place, replace the resistor .

Check the PCM. The manual also instructs you to measure voltage at the PCM 12-pin connector terminal C4 (Green wire). With the ignition ON, you should see battery voltage. If not, there could be an open or short in the wiring between the PCM and the fuel pump relay .

Check the fuel pump itself. If the relay and resistor are good, the pump inside the fuel tank may have failed. Listen for the hum when you turn the key. If you hear nothing, check for voltage at the fuel pump sub-harness connector .

How to Replace the Fuel Pump Relay

Replacing the fuel pump relay on a 2002 Acura RL is straightforward.

  1. Disconnect the negative battery terminal.
  2. Locate the relay in the trunk (behind the carpet, near the fuel pump access panel).
  3. Pull the old relay straight out of its socket.
  4. Plug in the new relay, making sure it is fully seated.
  5. Reconnect the battery terminal.
  6. Turn the key to the ON position and listen for the fuel pump to prime. If you hear a hum for two seconds, the relay is working.

Choosing the Right Replacement Relay

You can purchase an OEM replacement fuel pump relay from Acura using part number 39794-SDA-004, which replaces earlier numbers 39794-SDA-003 and 39794-SDA-305 . However, many aftermarket relays also work well. Make sure the relay you choose is rated for the correct amperage and has the same pin configuration as the original.

Why You Should Consider a High-Performance Fuel Pump

If you are already troubleshooting your fuel system, it is a good time to think about the condition of your fuel pump. The fuel pump is located inside the fuel tank, and accessing it requires removing the rear seat and the access panel . Since this is a labor-intensive job, it makes sense to replace the pump with a high-quality, reliable unit while you have the access panel open.

We recommend the KEMSO brand for your fuel pump replacement. KEMSO fuel pumps are high-performance, direct OEM replacement units. They are designed to meet or exceed the specifications of the original pump, ensuring proper fuel pressure and flow for your 2002 Acura RL. Every KEMSO fuel pump comes with a lifetime warranty, so you can be confident in its reliability. Whether you need a stock replacement or a higher-flow unit for performance upgrades, KEMSO has the right pump for your vehicle.

Visit KEMSO's website to find the perfect fuel pump for your Acura: https://www.kemsoracing.com/

Final Thoughts

Starting and stalling issues on a 2002 Acura RL can often be traced back to the fuel pump relay or the fuel pump itself . The fuel pump relay is located in the trunk, behind the rear carpet, and it is easy to test and replace. If the relay is good, check the fuel pump resistor and the wiring to the PCM. If all those components check out, the fuel pump inside the tank is likely the culprit. Always confirm the problem by listening for the fuel pump prime and by checking for voltage at the pump connector before tearing into the fuel tank. And when you do replace the pump, trust KEMSO for a durable, high-quality, lifetime-warranted solution.

For the best fuel pump options for your 2002 Acura RL, visit https://www.kemsoracing.com/


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