Skylark L4-138 2.3L SOHC VIN 3 MFI QUAD 4 (1992)
Radiator Cooling Fan Motor Relay: Description and Operation
Cooling Fan And Relay Circuit
NOTE: Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example.
Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications.
PURPOSE
The Electric Coolant Fan is used for engine and A/C condenser cooling and is controlled only by the ECM/PCM.
OPERATION
The coolant fan is controlled by the ECM/PCM through the fan relay based on inputs from the coolant and manifold air temperature sensors, A/C
control switch, A/C pressure sensor and vehicle speed sensor. The ECM/PCM grounds CKT 536 which turns "ON" the fan relay.
The coolant fan will be "ON" when:
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Coolant Temperature sensor signal indicating a temperature greater than 106°C (223°F).
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A/C is requested and vehicle speed less than 35 mph.
The coolant fan will be "ON" regardless of vehicle speed when:
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Coolant temperature sensor faults, Code 14 or 15 are present, or any fault code that is presently causing the "SERVICE ENGINE SOON" light
to be "ON."
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Coolant Temperature sensor signal indicating a temperature greater than 115°F-118°C (239°F-244°F).
-
A/C pressure sensor indicates overpressure.
NOTE: The coolant fans may remain "ON" up to 7 minutes after engine has been shut "OFF."