RX 400h AWD V6-3.3L (3MZ-FE) Hybrid (2007)
Radiator Cooling Fan Control Module: Testing and Inspection
COOLING FAN ECU
ON-VEHICLE INSPECTION
1. CHECK COOLING FAN ECU (No. 1 and No. 2)
a. Inspect the input voltage.
(1) Disconnect the cooling fan ECU connectors.
(2) Turn the ignition switch On.
(3) Measure the voltage between terminals +B and GND.
Standard voltage: 8 to 15 V
If the voltage is not as specified, check the fusible links, fuses, wire harness and fan relay.
(4) Reconnect the connectors.
HINT: Wire harness condition is diagnosed by cooling fan operation.
b. Check the HV control ECU power source.
c. Check RFC1 and RFC2 signal generation.
NOTICE: Perform this inspection when coolant temperature is 82°C (180°F).
(1) Connect an oscilloscope to terminals RFC1 (RFC2) and E1 of the HV control ECU.