On-Vehicle Inspection [11/2021 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus IS 500, 2023 Lexus IS 500, and 2022 Lexus IS 500. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT COOLING FAN ECU

Check and ensure the following conditions:
1. The engine switch is off.
2. The engine coolant temperature is less than 92°C (198°F).
3. The battery voltage is between 11 and 14 V.
4. The A/C switch is off.
Connect the pickup of a clamp-on ammeter around either of the 2 wires for the cooling fan motor.
Turn the engine switch on (IG) and wait for approximately 10 seconds. Check that the fans are not operating.
Start the engine. Check that the fans are not operating with the engine idling.
HINT:
- Make sure that the engine coolant temperature is less than 92°C (198°F).
- Turn the A/C switch off.

Check that the fans operate when the A/C switch is turned on.

Standard Current

Item	Condition	Specified Condition
Cooling fan motor	Battery voltage applied at 20°C (68°F)	15.0 to 21.0 A
No. 2 cooling fan motor	Battery voltage applied at 20°C (68°F)	15.0 to 21.0 A

HINT:

Make sure that the engine coolant temperature is less than 92°C (198°F).

Check that the fans operate when the engine coolant temperature sensor connector is disconnected.

Standard Current

Item	Condition	Specified Condition
Cooling fan motor	Battery voltage applied at 20°C (68°F)	15.0 to 21.0 A
No. 2 cooling fan motor	Battery voltage applied at 20°C (68°F)	15.0 to 21.0 A

After the engine is warmed up, check that the fans operate as shown in the illustration.

*a	Operating Diagram
*b	A/C OFF
*c	MAX HI
*d	HI
*e	LO
*f	OFF
*g	Fan Speed

HINT:

The engine coolant temperature at which the fans start operating is approximately 94°C (201°F).
This system can also be checked using the Techstream.
Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

Powertrain > Engine > Data List

Tester Display
Coolant Temp