Cooling Fan Control System Inspection

Connect the M-MDS to the DLC-2.
Perform the KOEO or KOER self test and verify that DTCs P0117:00, P0118:00, P0480:00 and/or P0481:00 are not shown using the KOEO and/or KOER self test. (See KOEO/KOER SELF TEST .)
- If DTCs P0117:00, P0118:00, P0480:00 and/or P0481:00 are shown, perform the applicable DTC troubleshooting procedure. (See DTC P0117:00 .) (See DTC P0118:00 .) (See DTC P0480:00 .) (See DTC P0481:00 .)
Start the engine and let it at idle with ECT is below 97°C {207°F}.

Verify that the cooling fans are not operating when A/C switch and fan switch are turned off.

If the cooling fan is operating, inspect for the following based on cooling fans status:

Cooling fan status		Inspection item
Cooling fan No. 1		Cooling fan No. 2
Low	Low	Cooling fan relay No. 1 (Stuck close)
High	High	PCM PID AC_REQ is always ON. Climate control unit CAN communication
Stop	High	Cooling fan relay No. 3 (Stuck close)

Using the M-MDS simulation function, turn FAN1 from the off position to the ON position, and verify that cooling fans No. 1 and No. 2 operate at low speed.

If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No. 1

Cooling fan No. 2

Stop

Cooling fan relay No. 1 (Stuck open)
Cooling fan No. 1 (Internal circuit open)
Cooling fan No. 2 (Internal circuit open)
Wiring harness in battery-cooling fan relay No. 1-cooling fan No. 1 (Open circuit, Fuse is blown by short to ground)
Wiring harness in cooling fan No. 1-cooling fan relay No. 3-cooling fan No. 2 (Open circuit)
Wiring harness in cooling fan No. 2-body ground (Open circuit)

High

Stop

Cooling fan relay No. 2 (Stuck close)
Wiring harness in cooling fan No. 1-cooling fan relay No. 3-cooling fan No. 2 (Short to ground) ⁽¹⁾

⁽¹⁾	The fuse between battery and cooling fan relay No. 3 may be burnt out.

Using the M-MDS simulation function, turn FAN1 and FAN2 from the off position to the ON position, and verify that cooling fans No. 1 and No. 2 operate at high speed.
- If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status		Inspection item
Cooling fan No. 1		Cooling fan No. 2
Stop	High	Cooling fan relay No. 2 (Stuck open) Wiring harness in cooling fan relay No. 2-body ground (Open circuit)
High	Stop	Cooling fan relay No. 3 (Stuck open) Wiring harness in battery-cooling fan relay No. 3 (Open circuit, Fuse is blown by short to ground)