Cooling Fan Control System Inspection

Connect the M-MDS to the DLC-2.
Start the engine and warm it up to normal operating temperature.
Perform the KOER self test. (See KOEO/KOER SELF TEST .)
Verify that DTC P0480:00 is not shown and the cooling fan operates during the KOER self test.
- If the DTC P0480:00 is displayed, perform the DTC inspection. (See DTC P0480:00 .)
- If the cooling fans do not operate, proceed to the following:
  - Inspect the following parts in the indicated order in accordance with fan operation conditions.
- Open circuit between battery positive terminal and cooling fan relay
- Open circuit between cooling fan relay and fan control module
- Open circuit between fan control module and ground
- Poor connection of the cooling fan relay
- Poor connection of the fan control module connector
  - If there is no malfunction:
- Replace the cooling fan component. (See COOLING FAN MOTOR REMOVAL/INSTALLATION .)
Start the engine and idle it at an engine coolant temperature of less than 97°C {207°F}.
Verify that the cooling fan does not operate when the A/C switch is turned off.

Cooling fan relay (stuck close)
Short to power supply in wiring harness between cooling fan relay and fan control module
Refrigerant pressure sensor
Climate control unit
CAN communication (PID: AC_REQ is on constantly)