CSF 3971 Drive Motor Inverter Cooler

CSF 3971 Drive Motor Inverter Cooler

CSF 3971 is an OE-style drive motor inverter cooler built with an aluminum core and plastic tanks for hybrid cooling applications. It is engineered for direct-fit replacement on select Toyota and Lexus models, including the Highlander, Sienna, Grand Highlander, RX350h, and RX450h+.

Key Features

• Aluminum core with plastic tank construction
• Cross-flow design for compact hybrid cooling layouts
• Upgraded B-tube design for stronger core construction
• Top hose fitting: 3/4 right
• Bottom hose fitting: 3/4 left
• Core dimensions: 26 in. length, 4 1/4 in. width, 7/8 in. thickness
• OEM-style replacement for inverter cooling service

Detailed Description

CSF 3971 is a drive motor inverter cooler designed around OE-style fitment and construction. The aluminum core helps transfer heat efficiently, while the plastic tank design follows the factory-style layout used on modern hybrid cooling systems. CSF notes this unit uses a higher-performance, stronger B-tube core design for added durability in demanding thermal environments. This part cross-references Toyota/Lexus OE numbers G9010-48100 and G9010-48110 for the same application.

Compatible With 2020-2025 Toyota Highlander, 2021-2025 Toyota Sienna, 2024-2026 Toyota Grand Highlander, 2023-2025 Lexus RX350h, and 2024-2025 Lexus RX450h+. CSF 3971 is also referenced by Quality-Built 13907.

What It Helps Address

• Inverter cooling system leaks from aging plastic tank assemblies
• Reduced heat exchange performance in hybrid cooling circuits
• Cracked or weakened factory-style cooler cores
• Service replacement needs after coolant contamination or overheating events
• Fitment issues when replacing the original inverter cooler on supported Toyota and Lexus models

Installation Notes and Tips

Verify hose orientation, inlet and outlet dimensions, and mounting points against the original unit before installation. This cooler uses a cross-flow layout with a 3/4 right top hose fitting and 3/4 left bottom hose fitting, so matching the factory routing is important for proper installation. Confirm vehicle application by model year before ordering.

Quality Assurance

CSF manufactures cooling components in ISO/TSO-certified facilities and validates radiator designs through engineering and wind-tunnel testing. With more than 50 years of production experience and a broad catalog of radiator and cooling applications, CSF applies established manufacturing controls to this inverter cooler platform.