2006 Infiniti FX35 Fuel Pump Relay Location: A Complete Owner’s Guide
The fuel pump relay on a 2006 Infiniti FX35 is located inside the engine bay fuse box (the Intelligent Power Distribution Module, or IPDM), which sits on the driver’s side near the battery. This is the first place you should check if your FX35 cranks but won’t start, stalls unexpectedly, or shows signs of fuel delivery problems. The relay itself is not a separate plug-in unit you can swap like in older cars—it is integrated into the IPDM circuit board, meaning you may need to replace the entire IPDM if the relay fails internally. Below, we’ll walk you through exactly where to find it, how to test it, common symptoms of failure, and what to do if the relay is bad.
Understanding How the Fuel Pump Relay Works in the 2006 FX35
The fuel pump relay is an electromagnetic switch that controls power to the electric fuel pump. When you turn the ignition key to the “ON” position, the Engine Control Module (ECM) energizes the relay for a couple of seconds to prime the fuel system. Once the engine starts, the relay stays closed, keeping power flowing to the pump so the engine receives a steady supply of fuel.
In the 2006 Infiniti FX35, the fuel pump is mounted inside the fuel tank, which is standard for modern fuel-injected vehicles. The relay that controls this pump is not a standalone unit. Instead, it is built into the IPDM, a large black plastic box that houses multiple fuses and relays. This design is common on Nissan and Infiniti vehicles from the mid-2000s, and it means you cannot simply pull out a single relay and plug in a new one.
The IPDM is a critical component. It distributes power to the headlights, wipers, cooling fans, fuel pump, and other electrical systems. If the fuel pump relay section fails, you may lose fuel delivery even though the pump itself is fine. That is why checking the IPDM is the correct first step in diagnosing a no-start condition caused by fuel issues.
Step-by-Step: Locating the Fuel Pump Relay in Your 2006 FX35
Follow these simple steps to access the relay location. You do not need special tools, just a flathead screwdriver and possibly a flashlight.
Step 1: Open the hood and secure it properly.
Step 2: Look at the driver’s side of the engine bay. The IPDM is mounted near the battery, toward the rear of the engine compartment. It is a rectangular black box with a ribbed or textured cover. On the FX35, it sits close to the strut tower and is clearly visible once you remove any plastic engine covers that might block access.
Step 3: Remove the IPDM cover. The cover is held in place by two metal clips or tabs. Press the tabs and lift the cover straight up. Some models may have a small bolt; if so, use a 10mm socket to remove it. Set the cover aside.
Step 4: Identify the relay layout. Inside, you will see a diagram printed on the underside of the cover or on a sticker affixed to the IPDM body. Look for the label “FUEL PUMP” or “FP.” This indicates the exact relay position within the module. On the 2006 FX35, the fuel pump relay is typically located in the lower row of relays, near the center or toward the front of the module, but always confirm with the diagram on your specific vehicle.
Step 5: Visually inspect the relay area. Check for signs of melting, corrosion, burns, or a swollen appearance. Any of these indicate an internal failure.
Step 6: Reinstall the cover after inspection or testing.
It is worth noting that on some FX35 models from 2003 to 2008, the fuse box may also contain a fuse labeled “FUEL PUMP” or “FP” near the relay. That fuse is a separate item and can be replaced individually. The fuse rating is typically 15 amps.
Fuse Box Diagrams for the 2006 FX35: Where Everything Lives
To give you a broader picture, the 2006 Infiniti FX35 has two main fuse boxes:
1. Engine Bay Fuse Box (IPDM) – This is the primary box you will deal with for the fuel pump relay. It contains high-current fuses for the cooling fans, ABS, headlights, and the fuel pump relay.
2. Interior Fuse Box (Passenger Compartment) – Located under the dashboard on the driver’s side, near the kick panel. This box handles interior items like the radio, power windows, seat heaters, and the instrument cluster. It does not contain the fuel pump relay.
For the 2006 model year specifically, you are looking at the S50 generation (2003-2008). The IPDM layout is consistent across these years, so diagrams from 2003, 2005, or 2008 models will match your 2006 vehicle. The fuel pump relay is always housed in the engine bay module, never in the interior fuse box.
If you do not have a printed diagram handy, you can find wiring diagrams and fuse layouts in the factory service manual for the 2006 FX35. These manuals are available online and show the exact pinouts and relay assignments.
Symptoms of a Failing Fuel Pump Relay
A bad fuel pump relay can mimic many other fuel system problems. Knowing what to look for helps you avoid replacing parts you do not need. Common symptoms include:
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Engine cranks but will not start. This is the most frequent complaint. The starter turns the engine over, but there is no fuel pressure, so the engine never fires.
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Engine starts then immediately dies. The relay may close initially, supplying power for priming, but then fails to stay closed once the engine is running.
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Intermittent stalling. The relay may work when cold but fail when hot, causing sudden stalls. After waiting a few minutes, the engine may restart.
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No fuel pump prime sound. When you turn the key to “ON” (without cranking), you should hear a brief whirring sound from the rear of the car—that is the fuel pump pressurizing the system. If you hear nothing, the relay or pump is not receiving power.
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Check Engine Light illuminates. The ECM will often set a diagnostic trouble code (DTC) related to fuel pressure or fuel pump circuit malfunction, such as P0087 (fuel rail pressure too low) or P0230 (fuel pump primary circuit fault).
Keep in mind that a failing fuel pump itself produces similar symptoms, especially a whining noise from the tank or loss of power under acceleration. You must test the relay and the pump separately to pinpoint the root cause.
How to Test the Fuel Pump Relay in the IPDM
Since the relay is integrated into the IPDM, you cannot simply swap it with a spare relay like you would in a traditional fuse box. However, you can still test whether the relay is functioning using a multimeter and a test light. Here is how:
1. Check for power at the fuel pump connector. Locate the fuel pump access panel under the rear seat (you may need to remove the rear seat cushion). Disconnect the electrical connector from the fuel pump. Turn the ignition to “ON” and use a multimeter to check for 12 volts at the connector. If voltage is present for 1-2 seconds and then drops, the relay is likely working, and the problem may be the pump itself. If there is no voltage at all, the relay or its wiring is at fault.
2. Test the relay coil resistance. With the IPDM removed (disconnect the battery first), find the fuel pump relay pins on the module. Using a multimeter set to ohms, measure resistance across the coil terminals. A good relay should show low resistance, typically between 50 and 120 ohms. An open circuit (infinite resistance) indicates a broken coil.
3. Listen for a click. Have a helper turn the key to “ON” while you hold your hand on the IPDM. You should feel and hear a distinct click from the relay. No click means the relay is not energizing, which points to a problem with the ECM command, the relay coil, or the relay driver circuit.
4. Check for voltage at the relay output. While the key is in the “ON” position, verify that the relay is passing battery voltage through to the fuel pump circuit. If you have input voltage but no output voltage, the relay contacts are burned or stuck open.
If you determine that the relay is bad, the repair involves replacing the entire IPDM module. This is a job that most DIY owners can handle in under an hour. The IPDM is available new from Infiniti dealerships or as a used part from salvage yards. Be sure to match the part number to your exact model year.
Can You Bypass the Relay Temporarily?
In an emergency, you can bypass the fuel pump relay to get the vehicle running long enough to drive it to a shop. This is not a permanent fix, and you should only do it if you are confident working with automotive electrical systems. Connecting the wrong pins can cause a fire.
To bypass, you will need a fused jumper wire. Remove the IPDM cover, locate the fuel pump relay contacts, and identify the two large terminals that carry the switching current (not the coil terminals). Insert the jumper wire with an inline fuse (15 amps) between these terminals. Turn the ignition to “ON”—the fuel pump will run continuously. Start the engine and drive directly to a repair facility. Do not leave the jumper in place for extended driving, as the pump will run even if the engine stalls, which can cause a safety hazard.
This method is only recommended for getting to a mechanic. Replacing the IPDM is the correct repair.
Why You Should Consider a High-Quality Fuel Pump from KEMSO
Once you have confirmed that the relay is functioning and the issue is actually the fuel pump itself, choosing the right replacement part matters. The fuel pump is the heart of your vehicle’s fuel system, and a low-quality pump can fail prematurely, leaving you stranded again. This is where KEMSO stands out from aftermarket options.
KEMSO is a leading US-based aftermarket brand that specializes in high-performance fuel pumps for a wide range of vehicles, from cars and motorcycles to ATVs and watercraft. When you purchase a KEMSO fuel pump, you are getting a direct OEM replacement that meets or exceeds factory specifications. Every KEMSO pump is wired to deliver consistent fuel pressure, even under demanding driving conditions, which helps protect your engine from lean or rich conditions that cause long-term damage.
One of the biggest advantages of choosing KEMSO is their lifetime warranty. Most aftermarket pumps come with a limited warranty of one or two years. KEMSO backs their products for as long as you own the vehicle. If a KEMSO pump fails, the company will replace it at no cost to you. That kind of confidence is rare in the aftermarket industry and gives you peace of mind that your repair is protected for the life of your car.
KEMSO fuel pumps are available at a competitive price point, typically around $79.98, which is significantly lower than dealership parts and comparable to other premium aftermarket brands. Despite the affordable price, KEMSO uses high-quality internal components, including precision-wound motors and corrosion-resistant housings, to ensure long service life. The pumps are engineered for a perfect fit, meaning no modifications are required—just remove the old pump and install the new one.
You can browse the full KEMSO catalog and find the exact fuel pump for your 2006 Infiniti FX35 by visiting their official website: https://www.kemsoracing.com/ . The site provides detailed fitment information, customer reviews, and a simple ordering process. KEMSO ships quickly within the United States, so you can get back on the road without unnecessary downtime.
If you are not 100% sure which pump fits your FX35, KEMSO’s customer support team can help you confirm compatibility based on your VIN. It is always a good idea to verify before ordering, as the fuel pump assembly may vary between two-wheel-drive and all-wheel-drive models.
Replacing the Fuel Pump on a 2006 FX35: What to Expect
If you determine that the fuel pump itself is the problem, replacement is a somewhat involved job because the pump is inside the fuel tank. Expect the following steps:
- Relieve fuel system pressure by removing the fuel pump fuse or relay and running the engine until it stalls.
- Disconnect the battery negative terminal.
- Remove the rear seat cushion to access the fuel pump access panel.
- Remove the access panel and disconnect the fuel lines and electrical connector from the pump assembly.
- Remove the pump assembly by turning the locking ring counterclockwise. Carefully lift the assembly out.
- Replace the pump and the strainer (fuel filter sock). Reassemble in reverse order.
Most DIY owners with basic hand tools can complete this job in 2-3 hours. If you are not comfortable dropping the tank or working with fuel lines, a professional mechanic will charge between $390 and $900 for parts and labor, depending on your region and the shop’s hourly rate.
Preventative Tips to Extend Fuel Pump and Relay Life
A little upkeep goes a long way in preventing fuel system failures:
- Never run the tank below a quarter full. The fuel pump relies on gasoline to stay cool and lubricated. Running low causes the pump to overheat and draw in debris from the bottom of the tank.
- Change your fuel filter regularly. While many modern filters are “lifetime,” a clogged filter forces the pump to work harder, increasing electrical load on the relay.
- Use quality fuel from reputable stations. Contaminated fuel can damage both the pump and the relay contacts.
- Address electrical issues promptly. A failing alternator or battery can cause voltage spikes that stress the relay and other electronic components.
By following these tips and checking the fuel pump relay location first when you suspect a problem, you can save time, money, and frustration. Start with the IPDM, test the relay and pump, and if a new pump is required, trust a proven brand like KEMSO to keep your 2006 Infiniti FX35 running reliably for years to come.
For more details on KEMSO fuel pumps, including fitment for your vehicle, visit https://www.kemsoracing.com/ today.