Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Cooling Fan Ecu

On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. CHECK COOLING FAN SYSTEM

CAUTION:

To prevent injury due to contact with an operating cooling fan, keep your hands and clothing away from the cooling fans when inspecting the cooling fan system.

(a) Check and ensure the following conditions:

(1) The engine switch is off.

(2) The engine coolant temperature is less than 95 °C (203 °F).

(3) The battery voltage is between 11 to 14 V.

(4) The A/C switch is off.

(b) Connect the pickup of a clamp-on ammeter around either of the 2 wires for the cooling fan motor.

(c) Turn the engine switch on (IG) and wait for approximately 10 seconds. Check that the cooling fans are not operating.

(d) Start the engine. Check that the cooling fans are not operating with the engine idling.

(e) Confirm the code mark on the cooling fan motor LH.

*a Code Mark

(f) Check that the cooling fans operate when the A/C switch is turned on.

(g) Measure the current while the cooling fan motors are operating.

Standard Current:

HINT:

Make sure that the engine coolant temperature is less than 95°C (203°F).

(h) Check that the cooling fans operate when the engine coolant temperature sensor connector is disconnected.

(i) Measure the current while the cooling fan motors are operating.

Standard Current:

(j) After the engine is warmed up, check that the cooling fans operate as shown in the illustration. HINT: The engine coolant temperature at which the cooling fans start operating is approximately 97°C (207°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

*a Operating Diagram *b MAX HI *c HI *d LO *e OFF *f Fan Speed