Cooling Fan Controls Symptom Troubleshooting

Symptom
Diagnostic Procedure
Also check for
Engine overheats
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Check the coolant level.
Check for the coolant leakage (from gaskets, hoses, O-rings, etc.).
Check for dirt, leaves, or insects on radiator and condenser.
Check for deteriorated coolant.
Check for damaged or deformed fan shroud.
Check for plugged or deteriorated radiator hoses.
Check for plugged heater core of hoses.
Check for a damaged cylinder head gasket.
The A/C condenser fan runs at low speed, but it does not run at high speed when the engine coolant temperature is above 96.5 °C (206 °F)
Cleanliness and tightness of all connectors
With the A/C off (if equipped) and the engine coolant temperature at 96.5 °C (206 °F) or below, the radiator fan run at high speed and the A/C condenser fan does not run. When the engine coolant temperature is above 96.5 °C (206 °F), both fans run at high speed
Remove the fan control relay, and test.
  • If the relay is faulty, replace it.
  • If the relay is OK, check for a short in the wire between the fan control relay 5P socket terminal No. 1 and radiator fan motor 2P connector terminal No. 1.
Cleanliness and tightness of all connectors
Both the radiator fan and the A/C condenser fan run at high speed with the ignition switch in ON (II), the A/C off (if equipped), and the engine coolant temperature below 94.5 °C (202 °F)
Check for a short in the wire between under-hood fuse/relay box connector No. 3 terminal No. 4 and ECM connector terminal A6.
Cleanliness and tightness of all connectors
Both the radiator fan and the A/C condenser fan run at low speed with the ignition switch in ON (II) and the A/C off (if equipped)
Check for a short in the wire between under-hood fuse/relay box connector No. 3 terminal No. 5 and ECM connector terminal A5.
Cleanliness and tightness of all connectors
With A/C: Both the radiator fan and the A/C condenser fan do not run at low speed with the A/C on
Cleanliness and tightness of all connectors
Both the radiator fan and the A/C condenser fan run at low speed, but radiator fan does not run at high speed when the engine coolant temperature is above 96.5 °C (206 °F)
Cleanliness and tightness of all connectors
Both the radiator fan and the A/C condenser fan do not run at high speed when the engine coolant temperature is above 96.5 °C (206 °F)
Check for an open in the wire between under-hood fuse/relay box connector No. 3 terminal No. 4 and ECM connector terminal A6.
Cleanliness and tightness of all connectors