Buy Toyota Sienna Radiator Fans

Quick Take

The Toyota Sienna cooling fan-also called the radiator fan, electric engine fan, or fan-shroud assembly-pulls fresh air through the radiator and A/C condenser to keep the minivan's 3.0 L, 3.3 L, 3.5 L and hybrid drivetrains from overheating, especially in stop-and-go traffic. It is an electric dual-fan setup controlled by a temperature sensor, relays and an ECU. When coolant nears 97 °C (207 °F) or whenever the A/C is on, the module sends power and both fans spin at up to 2 000 CFM to drop coolant temperature quickly. (Sienna Chat, Sienna Chat)

Part Overview

• Dual 12- to 14-inch brush-less motors mounted in one plastic shroud.
• Draws air across the radiator and condenser, so some catalogs list it as a radiator-condenser fan.
• Receives signals from the coolant-temperature sensor and A/C pressure switch through a fan control relay located in the engine-bay fuse box. (RepairPal.com)
• Fourth-generation (2021+) hybrid Siennas use a variable-speed fan ECU, but the shroud dimensions stay close to earlier years, simplifying interchange in many DIY swaps. (Toyota)

Learn more in Toyota's downloadable owner's manual.

How It Works

1. Sensor reads ≥ 97 °C. The coolant-temperature sensor reports rising heat. (Sienna Chat)
2. ECU closes relay. A 40-amp fuse and relay send 12 V to each motor. (YouTube)
3. Fans pull air. Blades draw outside air through radiator fins, dropping coolant temperature.
4. ECU cycles off. When temperature falls to ~90 °C, the relay opens and the fans rest.

This simple on-off cycle repeats hundreds of times a day and can run even with the key off on hybrids during battery cooling. (static.nhtsa.gov)

When Things Go Wrong

← scroll table horizontally →

RepairPal lists the radiator-fan motor, relay and temp sensor as the top three culprits for Sienna overheating. (RepairPal.com)

Fit & Years

• 1998-2003 (gen 1): 3.0 V6, single-speed motors, two-pin connectors.
• 2004-2010 (gen 2): 3.3 V6; Toyota updated the shroud-older units do not swap without trimming tabs.
• 2011-2020 (gen 3): 3.5 V6; three-pin variable-speed motors share plugs with many Lexus RX models.
• 2021-2025 (gen 4 hybrid): 2.5 L hybrid; shroud adds integrated ECU but bolt pattern matches gen 3. (static.nhtsa.gov)

Always match plug style, blade count (5 & 7 blades), and shroud width before ordering a replacement.

DIY Replacement

1. Disconnect battery to stop accidental fan spin.
2. Remove upper radiator support, then lift shroud straight up (Toyota repair bulletin shows harness clip locations). (Toyota-Tech)
3. Unplug both motors and temp sensor.
4. Transfer rubber isolators to the new shroud.
5. Torque fan-motor screws to 71 in-lb (low torque-over-tightening cracks the plastic). (static.nhtsa.gov, QCLT Share)
6. Refill coolant, start engine, and confirm fans cycle at idle with A/C on.

A short how-to video on fuse & relay checks can help if your fan still will not start.

Care Tips

• Keep fins clear. Blow out leaves and bugs at every oil change.
• Inspect connectors. Clean corrosion and ensure the locking tab clicks. (static.nhtsa.gov)
• Watch temp gauge. If the needle creeps past half, pull over and make sure the electric fan is spinning before continuing.

Safety & Green

The fan can start anytime-even with the hood up-whenever the ECU sees high coolant or A/C pressure, so keep fingers and tools clear.

The shroud is usually PA66 (glass-filled nylon). Toyota's sustainability reports note that this thermoplastic can be ground, re-pelletized, and reused in under-hood brackets, lowering CO₂ footprint. (EPA NEPIS, Engineering.com) Dispose at a plastics recycler, not the trash.

Tech Data

• Operating temp ON ≈ 97 °C (207 °F); OFF ≈ 90 °C (194 °F) (Sienna Chat)
• Current draw: 25-30 A both fans running.
• Fuse rating: 40 A "RAD NO. 1" in engine-bay fuse box. (YouTube)
• Motor-screw torque: 71 in-lb; radiator-reservoir bracket: 44 in-lb. (static.nhtsa.gov, QCLT Share)

Frequently Asked Questions

Q: Why does the Sienna have two engine fans?
A: One fan cools the engine radiator, and the second helps with the A/C condenser; both can run together for extra airflow at idle. (Sienna Chat)

Q: At what temperature should the fans start?
A: Around 97 °C (207 °F). If they stay off past that, test the relay and sensor. (Sienna Chat)

Q: Can I drive if only one of the two fans spins?
A: It may be safe while moving, but at stops the engine can overheat fast-repair before regular use. (Sienna Chat)

Q: Why do the fans stay on after I shut off the engine?
A: The ECU sometimes runs them to cool the engine bay or hybrid battery; they should stop within 5 minutes. If not, the relay could be stuck. (YouTube)

Q: Do I need to drain coolant to change the fan assembly?
A: No, if you're careful-the shroud lifts out of the radiator without opening the cooling system on most models. (Toyota-Tech)

Q: What tools are required?
A: 10 mm socket, long Phillips screwdriver, trim-clip remover, and a torque wrench capable of inch-pounds. (static.nhtsa.gov)

Q: Is the fan covered by Toyota's warranty?
A: The fan motor is listed under "cooling system components" in the 3-year/36 000-mile basic warranty. Check your year's guide for exact terms. (Toyota)

Q: How loud should the fan be?
A: A healthy fan is a steady whoosh. Grinding, clicking, or roaring means worn bearings or blade damage. (Sienna Chat)

Use this guide to understand, diagnose, and safely replace the Toyota Sienna cooling-fan assembly, keeping your minivan cool and your passengers comfortable.