On-Vehicle Inspection

WARNING: This page is about a different variant/trim than selected.

CHECK COOLING FAN SYSTEM

Check the input signal and output current.

HINT:

Be sure to perform the inspection with an engine coolant temperature of less than 92°C (198°F).

Connect the 400 A probe of an ammeter to the cooling fan motor (M+), and then the No. 2 cooling fan motor (S+) on the wire harness side.
Connect the Techstream to the DLC3.
Using the oscilloscope, check the waveform between terminals D61-10 (RFC) and B49-6 (E1) of the ECM.
HINT:

Enter the following menus: Powertrain/Engine/Active Test/Control the Electric Cooling Fan.

Fig 1: Identifying ECM Connector Terminals And Waveform

Standard Waveform

WAVEFORM REFERENCE

Condition	Input Signal	Output Current
Engine stopped (Ignition switch ON)	Waveform 1 (Duty ratio 0%)	(Fans stop)
Engine idling (A/C OFF) (The coolant temperature is less than 95°C (203°F))	Waveform 1 (Duty ratio 0%)	(Fans stops)
Engine idling (A/C ON)	Waveform 2 (Duty ratio 30 to 70%)	(Fans operate) w/o Towing package 5.3 to 11.3 A for No. 1 cooling fan motor 5.3 to 11.3 A for No. 2 cooling fan motor w/Towing package 10.0 to 16.0 A for No. 1 cooling fan motor 10.0 to 16.0 A for No. 2 cooling fan motor
Engine idling (Engine coolant temperature sensor connector disconnected)	Waveform 3 (Duty ratio 30 to 70%)	(Fans operate) w/o Towing package 5.3 to 11.3 A for No. 1 cooling fan motor 5.3 to 11.3 A for No. 2 cooling fan motor w/ Towing package 10.0 to 16.0 A for No. 1 cooling fan motor 10.0 to 16.0 A for No. 2 cooling fan motor

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, cooling fan motor or power source circuit.