P0480 Fan 1 Control Circuit

/ Engine DTCs / By
GENERAL DESCRIPTION
When the ambient air temperature is warm or the airflow across the engine is low, the engine coolant temperature can become hot. If the coolant temperature becomes too hot, it is possible that the engine could be damaged. The purpose of activating the engine compartment ventilation fan is to help reduce the engine coolant temperature to a level that is not threatening to engine performance and maintains the air conditioning system pressure at safe levels.
Electric fan is responsible for causing air movement around the engine coolant radiator. The amount of air movement caused by the fan is controlled based on the Vehicle Speed, coolant temperature, A/C pressure status, A/C switch request status, and A/C clutch state. A duty cycle is determined based on these input parameters. This duty cycle corresponds to fan speed which correlates to the amount of air movement caused by the fan. The increased air movement enhances the heat exchanger function of the radiator in the confined space of the engine-compartment, thereby reducing the engine coolant temperature more quickly.

 

COMPONENT LOCATION

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MONITOR GDS DATA
1.
Connect GDS to Data Link Connector(DLC).
2.
IG “ON”.
3.
Select “DTC” button, and then Press “DTC Status” to check DTC’s information from the DTCs menu.
4.
Read “DTC Status” parameter.

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5.
Is parameter displayed “Present fault”?
 

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▶ Go to next procedure.

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▶ Fault is intermittent caused by poor contact in the sensor’s and/or PCM’s connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary
TERMINAL AND CONNECTOR INSPECTION
1.
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3.
Has a problem been found?
 

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▶ Repair as necessary and go to “Verification of Vehicle Repair” procedure

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▶ Go to “Power Circuit Inspection” procedure.

 

POWER CIRCUIT INSPECTION
■ Check voltage
1.
IG “OFF” and disconnect Cooling fan module connector.
2.
IG “ON”.
3.
Measure voltage between power supply terminal of Cooling Fan Relay Low control harness connector and chassis ground
4.
Measure voltage between power supply terminal of Cooling Fan Controller harness connector and chassis ground.
 Approx. 12V

 

 
 

 

5.
Is the measured voltage within specification?
 

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▶ Go to “Control Circuit Inspection” procedure.

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▶ Check if cooling fan fusible link 40A is open or not installed.
▶ Check if cooling fan relay is not installed or faulty.
▶ Check if the line between cooling fan relay and Cooling Fan Controller is open.
▶ Repair or replace as necessary and then, go to “Verification of Vehicle Repair” procedure.

 

CONTROL CIRCUIT INSPECTION
■ Check signal waveform
1.
IG “OFF” and disconnect Cooling fan module connector.
2.
IG “ON”.
3.
Check if the cooling fan is controlled in the way of control by PCM when the cooling system operates.
4.
Is the measured signal waveform normal?
 

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▶ If the problem is corrected after substituting with a known – good Cooling Fan module, replace it. If the problem is pending, check for proper operating after substituting with a known – good PCM and then if the problem is corrected, replace PCM and go to “Verification of Vehicle Repair” procedure.

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▶ Check that harness connected at engine compartment junction block is disconnected or not.
▶ Check the line between control terminal of Cooling Fan Controller harness connector and cooling fan control terminal of PCM harness connector for open.
▶ Repair or replace as necessary

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