Toyota 2GR-FE Manual page 782

Waveform 1
Waveform 2
Waveform 3
2GR-FE COOLING – COOLING FAN ECU
(e) Inspect the input signal and output current.
1 V/DIV
20 ms/DIV
GND
Condition
Engine stopped
(Ignition switch on (IG))
1 V/DIV
Engine idling
(A/C OFF)
20 ms/DIV
Engine idling
(A/C ON)
Engine idling
(Coolant temperature
sensor connector
GND
disconnected)
1 V/DIV
20 ms/DIV
GND
A126255E01
NOTICE:
Be sure to perform the inspection with the
radiator coolant temperature less than 95°C (203
°F).
(1) Connect the 400 A probe of the ammeter to
terminal M+ of the cooling fan motor.
(2) Set the intelligent tester to the oscilloscope
function.
(3) Using the intelligent tester, check the waveform
between terminals RFC and E1 of the ECM.
Standard waveform
Input Signal
Waveform 1
(Duty ratio 0 %)
Waveform 1
(0 %)
Waveform 2
(30 to 70 %)
Waveform 3
(30 to 70 %)
HINT:
• If the input signal is abnormal, there is a
malfunction in the ECM or cooling fan ECU.
• If the output current is abnormal even when
the input signal is normal, there is a
malfunction in the cooling fan ECU (RFC) or
motor.
CO–17
Output Current
(Fan stops)
(Fan stops)
2 to 11 A
(Fan operates)
2 to 11 A
(Fan operates)
CO