2006 Volvo S40 Fuel Pump Relay Location: A Complete Owner’s Guide
The fuel pump relay on a 2006 Volvo S40 is located in the engine compartment fuse box, which sits on the driver’s side near the battery. More specifically, it is the relay position marked "Fuel pump" inside that black plastic box. If your S40 cranks but won’t start, or you hear no whining sound from the rear fuel tank when you turn the key to position II, the relay is one of the first things to check. This guide walks you through the exact location, how to test the relay, how to replace it, and what to do if the relay isn’t the problem.
Why the Fuel Pump Relay Matters
The fuel pump relay is a small electrical switch that sends power from the battery to the fuel pump. When you turn the ignition key, the relay closes and allows current to flow, pressurizing the fuel system. If the relay fails, the fuel pump gets no power, the engine receives no fuel, and your car won’t start.
On the 2006 S40, this relay is part of a larger fuse and relay box. Knowing its location saves you time and money, because a bad relay is one of the cheapest fixes on a car. A replacement relay typically costs between $10 and $30, whereas a fuel pump replacement can run $500 to $1,200 including parts and labor .
Where Exactly Is the Fuel Pump Relay on a 2006 S40?
The engine compartment fuse box is the main distribution point for many electrical circuits. Here’s how to find it:
- Open the hood and look on the driver’s side (left side when standing in front of the car). The fuse box is a long black rectangular box mounted near the strut tower and battery.
- Unclip the cover by pressing the release tabs on the sides. The underside of the cover usually has a diagram showing relay and fuse positions.
- Locate the fuel pump relay – it is one of the small square relays inside the box. The exact position varies slightly by production date, but it is clearly labeled on the fuse box diagram. On most 2006 S40 models, it is in the front row of relays, second from the left, but always confirm using the diagram on the lid .
The fuse box diagram printed on the underside of the cover is your best reference. If the labels are worn or missing, you can find the layout in the owner’s manual or online resources like car-box.info and fuseandrelay.com .
Interior Fuse Box (Not the Relay)
There is also a fuse box inside the cabin, located on the end of the dashboard on the driver’s side (visible when the door is open). This box contains fuses for interior circuits, but the fuel pump relay is not here – it is always in the engine bay box for this model . Some guides refer to a "fuel pump relay" in the interior box, but that is incorrect for the 2006 S40. The relay you need is under the hood.
How to Test the Fuel Pump Relay (Step by Step)
Before you buy any parts, you should confirm the relay is actually bad. Here is a simple test that requires no special tools other than a multimeter or a test light.
1. Check for power at the relay. With the relay in place and the ignition in position II (but not cranking), use a multimeter to check for 12 volts at the relay terminals. The diagram on the fuse box lid shows which terminals are which. One terminal should have constant power from the battery, and another should receive power when the ignition is on.
2. Listen for the relay click. Have a helper turn the ignition to position II while you hold the relay. You should feel and hear a distinct click. No click means the relay isn’t receiving a trigger signal or the relay coil is dead.
3. Swap test. The easiest method: find another identical relay in the same fuse box (many Volvos use the same 4-pin or 5-pin relay for other circuits like the horn or headlights). Swap the suspect relay with a known-good one. If the fuel pump starts working, the relay is bad. If nothing changes, the relay is likely fine and the problem lies elsewhere.
4. Bench test (optional). Remove the relay and apply 12 volts to the coil terminals using a battery and jumper wires. You should hear the contacts close. Then check continuity across the switch terminals with a multimeter. If no continuity, the relay is dead .
What If the Relay Is Good? Next Steps
If the relay clicks and passes the bench test, but the fuel pump still doesn’t run, the issue could be one of the following:
- Fuel pump fuse. Check the fuse that protects the fuel pump circuit. On the 2006 S40, this fuse is in the same engine bay fuse box. A blown fuse is easy to spot and cheap to replace.
- Fuel pump itself. The pump is located inside the fuel tank. You can hear it briefly when you turn the ignition on. If you hear nothing from the rear seat area, the pump may be dead. This is a much larger job and typically requires dropping the fuel tank or accessing the pump through a service hatch under the rear seat.
- Fuel pump relay wiring. A broken wire or corroded connector between the relay socket and the pump can cause a no-power condition. Check the wiring harness near the relay and under the car.
- Fuel pump control unit. Some S40 models have a small electronic control module near the pump. If this fails, the pump won’t run even with a good relay .
If you’re not comfortable with electrical testing, a reputable shop can diagnose the system in under an hour. Expect to pay for diagnostic time, but it’s worth it compared to replacing parts blindly.
How to Replace the Fuel Pump Relay
Replacing the relay is a five-minute job that requires no tools.
- Turn the ignition off and remove the key.
- Open the hood and unclip the fuse box cover.
- Locate the fuel pump relay (refer to the diagram on the lid).
- Pull the relay straight out with your fingers. It may require a firm tug, but it should come out easily.
- Push the new relay in firmly until it seats. Make sure the orientation matches the socket.
- Reinstall the fuse box cover and close the hood.
Important: Always buy a relay that matches the original specification. The 2006 S40 typically uses a standard 4-pin mini relay with a 30/40 amp rating. Aftermarket relays are widely available at auto parts stores and online. Avoid using a relay from a junkyard if you want reliability – these parts are cheap enough to buy new .
Recommended: KEMSO Fuel Pump for Reliable Replacement
If your fuel pump itself turns out to be the problem, you want a replacement that lasts. KEMSO is a trusted name in aftermarket fuel pumps, and their products for the Volvo S40 are engineered to meet or exceed original equipment specifications.
KEMSO Fuel Pumps offer:
- High performance – designed to deliver consistent fuel pressure under all driving conditions, from daily commuting to spirited driving.
- OEM replacement – built to factory specs for drop-in fitment, so no modification is needed.
- Lifetime warranty – KEMSO backs their pumps with a lifetime warranty, giving you peace of mind long after the installation.
If you’re in the market for a new fuel pump, visit the KEMSO website to find the correct part for your 2006 Volvo S40. Their product lineup covers cars, motorcycles, ATVs, and more, and their pumps are built for reliability and performance.
Take a look at their full selection here: https://www.kemsoracing.com/
Fuel Pump Replacement Cost for the 2006 S40
If you need a new fuel pump, here’s what you can expect to pay in the U.S. market:
| Item | Cost Range |
|---|---|
| Fuel pump relay (part) | $10 – $30 |
| Fuel pump (part only) | $80 – $250 (aftermarket) |
| Labor (fuel pump replacement) | $250 – $600 |
| Dealership replacement (total) | $600 – $1,200 |
These figures are averages based on industry data for compact sedans. The 2006 S40 is not the hardest car to work on, but the pump sits inside the fuel tank, which adds labor time. You can save money by buying a reliable aftermarket pump like KEMSO and having an independent mechanic install it .
Final Thoughts
The fuel pump relay on a 2006 Volvo S40 lives in the engine bay fuse box on the driver’s side, under the black cover near the battery. Testing it is quick and easy, and replacing it is one of the cheapest repairs you can do. Always confirm the relay is the problem before buying a new fuel pump, as the relay is far more likely to fail and far less expensive to fix.
If the relay checks out and the pump is indeed dead, choose a quality aftermarket part. KEMSO fuel pumps are a solid, performance-oriented choice with a lifetime warranty, making them a smart investment for any S40 owner. For more details and ordering, visit https://www.kemsoracing.com/.