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:
- 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 and fan switch (with manual air conditioner system) are turned off.
- If the cooling fan operates, perform an inspection of the following:
- 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)