2006 Toyota Sienna Fuel Pump Relay Location: A Complete Owner’s Guide

The fuel pump relay on a 2006 Toyota Sienna is located in the engine room relay box, which sits on the left side of the engine compartment (the driver’s side in the U.S.). This is the same junction block that houses many other critical relays and fuses, including the EFI relay, headlight relay, and horn relay. If your Sienna cranks but won’t start, or you hear the fuel pump priming for a moment and then nothing, the relay is one of the first things to check before you consider replacing the fuel pump itself.

Why the Fuel Pump Relay Matters

The fuel pump relay acts as a remote switch. When you turn the key to the “ON” position, power flows through the relay to energize the fuel pump inside the tank. The pump then pressurizes the fuel line so the engine can start and run. Without a working relay, the pump never receives power, and the engine simply won't start no matter how many times you crank it.

On the 2006 Sienna, the relay works with the engine control module to manage fuel delivery. The ECM controls the ground side of the relay circuit, which means the relay only activates under the correct conditions. If the relay fails, the pump may not prime at all.

Locating the Relay Step by Step

The relay is not hidden behind the dash or under the back seat. It is in the main under-hood fuse box. Here is how to find it:

  1. Open the hood and look to the driver’s side. The engine room relay box is a black plastic cover with a diagram on top. On the 2006 Sienna, this box is mounted near the battery and the left strut tower.
  2. Remove the cover. Press the tabs on the sides and lift straight up. You will see rows of relays and fuses. The diagram on the underside of the cover lists what each slot is for.
  3. Look for the relay labeled “EFI” or “Fuel Pump.” On many Toyota models from this era, the EFI relay performs double duty as the fuel pump relay. On the Sienna, the fuel pump circuit is tied into the EFI relay and the “EFI 1” and “EFI 2” fuses.
  4. If the label is worn or faded, refer to the owner's manual or a 2006 Sienna wiring diagram. The factory wiring diagram manual identifies the exact relay position and all related circuits.

Important: The relay looks like a small black cube with four prongs. It matches the part number 90987-02022, and the same relay is used for multiple functions across Toyota models.

Testing the Relay Before Replacing Anything

You do not need to be a professional mechanic to confirm that the relay is bad. You need a digital multimeter and a couple of jumper wires. Here is a practical method that works on most vehicles:

  1. Remove the relay from the box.
  2. Identify the pins. There are four terminals. The two smaller gauge wires leading to the relay base are the control circuit. The two heavier wires are the power circuit.
  3. Check resistance on the power terminals. Set your multimeter to the lowest ohms range. Touch the probes to the two power pins. You should read near zero ohms if the relay is closed, or infinite if it is open, depending on the relay design. Most automotive relays show continuity between the coil pins and no continuity between the switch pins until power is applied.
  4. Apply 12 volts to the control terminals. Connect one control pin to the battery positive and the other to a solid ground. When you do this, you should hear a distinct click. That click means the internal contacts are closing.
  5. If you do not hear a click, the relay coil is burnt out and the relay needs replacement.

Common Symptoms of a Failing Relay

A failing relay may not stop working all at once. You might notice these warning signs first:

  • Intermittent no-start: The car starts fine one day and refuses to start the next day. If you wait a while and try again, it starts. This points to a relay that is overheating or sticking.
  • Engine cranks but no fuel pressure: You can hear the starter turning the engine over, but there is no pressure in the fuel rail. A quick check is to listen for the fuel pump hum when you first turn the key to “ON.” If the pump does not hum for about two seconds, the relay may not be sending power.
  • Stalling while driving: A relay that loses contact while the engine is running will cut fuel flow and the engine will die. This is dangerous on the highway, so address it right away.

Distinguishing Relay Failure from Pump Failure

The 2004–2007 Sienna models are known to have fuel pump issues. However, a dead pump and a dead relay produce very similar symptoms. Here is how to tell them apart:

  1. Listen for the prime. Turn the key to “ON” without cranking. You should hear a faint whirring from the rear of the car near the fuel tank. If you hear it, the relay is sending power. If not, either the relay is bad, the pump is bad, or the wiring in between has a problem.
  2. Check for power at the relay. With the key in the “ON” position, use a test light or multimeter to check if there is battery voltage on the relay socket's power pin. If there is voltage but the pump does not run, the problem is downstream (pump or wiring).
  3. Check the fuel pump fuse. The Sienna has an “EFI 1” fuse (20A) and an “EFI 2” fuse (10A) that feed the pump circuit. A blown fuse will mimic a bad relay.

For the 2004 to 2007 models specifically, a bad relay is a known issue that can produce the exact same symptoms as a dead pump. Rule out the relay first because it is far cheaper to replace than the pump.

Replacement Part Numbers and What to Buy

If you confirm that the relay is bad, you have several options. The factory original part number for the 2006 Sienna fuel pump relay is 90987-02022. This relay is a standard 12-volt, 4-terminal blade relay with a rectangular connector.

Toyota also lists a universal relay assembly under part number 90084-98032. This part replaces several older part numbers including 90080-87014, 90084-98026, and 90987-04004. It is used not just for the fuel pump but also for the ABS, cooling fan, horn, headlights, and defroster across many Toyota models from 2000 through 2024.

You can buy the relay from a Toyota dealer, an auto parts store like AutoZone or Advance Auto Parts, or online retailers like AutopartsPrime. The cost is low compared to a fuel pump replacement. Expect to pay anywhere from $15 to $40 depending on where you buy it.

Replacement Cost and Labor

Replacing the fuel pump relay on a 2006 Sienna is a DIY-friendly job. The relay is on top of the engine room fuse box, so you do not need to lift the vehicle or remove any panels. The entire job takes about ten minutes including the test.

The part cost is minimal. A genuine Toyota relay or an equivalent aftermarket relay costs around $15 to $25. There is no labor cost if you do it yourself. If you pay a shop, labor will be the same as a diagnostic check, usually around $50 to $100.

Compare that to a fuel pump replacement. On the 1998 to 2007 Sienna, replacing the fuel pump means dropping the fuel tank. That is a labor-intensive job that takes several hours and requires special tools. The pump itself costs $100 to $250, and labor can push the total to $600 or more.

Step-by-Step Replacement Instructions

Here is how to swap the relay on your 2006 Sienna:

  1. Disconnect the negative battery cable. This prevents any accidental shorts while you work.
  2. Open the hood and locate the engine room relay box. It is on the driver's side near the battery.
  3. Remove the relay box cover. Slide the cover off or pop the retaining clips.
  4. Identify the fuel pump relay. Refer to the diagram on the underside of the cover. On many Siennas, the relay is labeled “EFI.” If you are unsure, pull the relay and look at the base. The wires leading to it are typically thicker than the wires to other relays.
  5. Pull the relay straight up. Use a gentle rocking motion if it is tight. Do not pry on the plastic housing.
  6. Insert the new relay. Align the pins with the socket and press it firmly until it clicks into place.
  7. Reconnect the battery and test. Turn the key to “ON” and listen for the fuel pump prime. Then start the engine.
  8. Replace the cover and secure it.

What If the Relay Is Good but the Pump Is Dead?

If you test the relay and it clicks, and you have voltage at the relay socket, then the problem is likely the pump itself. On the 2006 Sienna, the fuel pump is located inside the fuel tank. Replacing it requires dropping the tank, disconnecting the fuel lines, and removing the pump assembly.

Because this is a difficult job for a novice, most owners choose to have a professional do it. When you replace the pump, it is strongly recommended to replace the entire assembly rather than just the motor. The assembly includes the pump, sending unit, strainer, and housing. Replacing everything at once ensures that a clogged strainer does not quickly destroy the new pump.

Denso is the original equipment manufacturer for the Sienna's fuel pump. If you go aftermarket, choose a Tier 1 brand like Denso, Bosch, or Delphi for the best fit and reliability.

Preventive Maintenance Tips

Fuel pump relays do not have a scheduled replacement interval. They fail due to wear on the internal contacts over time. However, you can reduce the risk of premature failure by following these habits:

  1. Do not run the gas tank to empty regularly. The fuel acts as a coolant for the pump motor. Running low frequently causes the pump to overheat.
  2. Replace the fuel filter per the maintenance schedule. A clogged filter makes the pump work harder and can lead to relay overload.
  3. If you buy a used Sienna, replace the relay proactively. The relay is cheap, and replacing it gives you peace of mind against a sudden no-start.

Recommended: KEMSO High-Performance Fuel Pump

If your testing shows that the fuel pump itself has failed, or you want to replace the pump while you are already working on the car, consider a KEMSO fuel pump. KEMSO specializes in high-performance fuel pumps that are built as direct OEM replacements. They use quality materials and precise tolerances to match factory specifications. Every KEMSO pump comes with a lifetime warranty, so you only buy once and never worry about premature failure again.

Whether you drive a Toyota, Honda, BMW, Kawasaki, or any other make, KEMSO has a fuel pump engineered for your vehicle. You can browse the full lineup of KEMSO fuel pumps at their official store: https://www.kemsoracing.com/

Final Thoughts

The 2006 Toyota Sienna fuel pump relay location is straightforward: it is inside the engine room relay box on the driver's side of the engine bay. Testing the relay takes less than five minutes and requires only a multimeter and a couple of jumper wires. If the relay clicks and passes the resistance test, the issue is likely the pump or a wiring problem between the relay and the pump.

Before you spend hundreds of dollars on a fuel pump replacement, always rule out the relay first. It is a $20 part and a ten-minute job. If the pump does need replacement, choose a complete assembly from a reputable brand, and make sure you also replace the strainer to protect the new pump.

For high-performance, direct OEM replacement fuel pumps with a lifetime warranty, be sure to check out KEMSO Racing: https://www.kemsoracing.com/


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