HKS 27002-AT002 Transfer Oil Cooler Kit for TOYOTA GR Yaris (XP210) 2025-

The Transfer Unit is mounted at the rear of the engine and redirects torque from the transaxle by 90°, sending it to the rear wheels.

The GR Yaris AWD system uses an electronically controlled coupling in front of the rear differential to manage power distribution according to the selected driving mode: NORMAL, GRAVEL, or TRACK.

During extended high-load driving (e.g., on track), the system automatically switches to 2WD to prevent overheating.

The HKS Transmission Oil Cooler helps reduce oil temperature, extend oil life, and protect the transfer unit.

With the Transfer Protection Cancel Program, full-time AWD can be used even on track. Note: This may void your vehicle’s warranty — check with your dealer.

Kit Contents:

• Transfer cooling pipe
• Electric oil pump
• Pump controller
• Oil filter
• Mounting bracket
• Hoses, wiring, and fittings

Features:

• The cooler operates independently of the engine coolant, engine oil, or intercooler systems.
• High-capacity electric pump with controller: enters standby at low temperatures and activates around 60°C.
• For vehicles with the cancel program, the pump starts automatically if TRACK mode is selected within one minute of startup.
• Special outlet fitting with sensor and drain port allows easy service.

Pump Controller Modes:

• AUTO – for vehicles without the cancel program
• FULL AUTO – for vehicles with the cancel program
• MANUAL – for maintenance

Additional Functions:

• Current monitoring: enters standby if current exceeds safe levels; tests every 30 seconds
• Overcurrent protection
• Transfer protection cancel function (only for compatible vehicles)

Usage Notes:

• Intended for track use. Keep the pump off during daily driving.
• Do not operate the pump with cold oil (below 60°C).
• If the pump frequently turns on/off in AUTO/FULL AUTO, the oil is too cold.
• Use only stock gear oil or HKS G900 75W-90. Do not use thicker oils.
• The cancel function works only with the correct software. Do not connect the “4WD mode select switch” if not supported.
• Minor modifications required:
  • Trimming bumper ducts or inner fender air guides
  • Altering radiator guides and engine undercover

Track Test Results (Fuji Speedway):

• Without cooler: oil temp rose to ~150°C and test was stopped.
• With cooler: stabilized around ~100°C.
• Approx. 50°C difference shows the cooler's effectiveness.

Additional Info:

• GR Yaris (Japan), from June 2025
• Vehicles made Aug–Dec 2020 do not include transfer protection