Chevrolet Sonic Repair Manual: Cooling Fan Description and Operation (LWE, LUW)
System Overview
The engine cooling fan system is composed of one cooling fan, 2 relays, the engine control module (ECM), and the associated wiring. The cooling fan assembly includes 1 resistor mounted in the cooling fan shroud. The cooling fan resistor may be a stand alone component, or a part of the cooling fan motor and harness assembly. This combination of components enables the ECM to operate the cooling fan at 2 speeds using two fan control circuits. The ECM will operate the cooling fan at either Low or High speed based on the cooling requirements.
Low Speed Operation
The ECM applies ground at the FAN 1 control circuit for the coil side of the low speed cooling fan relay. The energized low speed relay switch closes to supply B+ through the cooling fan resistor, to the engine cooling fan motor. The result is cooling fan operation at a reduced speed.
High Speed Operation
The ECM applies ground at the FAN 2 control circuit for the coil side of the cooling fan high speed relay. The energized high speed relay switch closes to supply B+ directly to the engine cooling fan motor, by-passing the cooling fan resistor. The result is cooling fan operation at full speed.
Cooling Fan Description and Operation (LUV)
The engine cooling fan system is composed of one cooling fan, a series of 5 relays,
the engine control module (ECM), and the associated wiring. The cooling fan assembly
includes two resistor ...
Engine Coolant Fan Shroud Replacement (LDE LUW)
Engine Coolant Fan Shroud Replacement
Callout
Component Name
Preliminary Procedure
Remove the radiator surge tank. Refer to Radiato ...
Other materials:
Dolly Towing from the Front
The vehicle can be towed from the front using a dolly. To tow the vehicle using
a dolly, follow these steps:
1. Attach the dolly to the tow vehicle following the dolly manufacturer's instructions.
2. Drive the front wheels onto the dolly.
3. Put an automatic transmission in P (Park) or a ...
SIR Service Precautions
General Service Instructions
Warning: When performing service on or near the SIR components
or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling
and Enabling . Failure to observe the correct procedure could cause deployment
of the SIR components, person ...
Air Conditioning Evaporator Thermal Expansion Valve Replacement
Air Conditioning Evaporator Thermal Expansion Valve Replacement
Callout
Component Name
Preliminary Procedure
Recover the refrigerant. Refer to Refrigerant Recovery and Recharging.
Remove the air conditioning evaporator hos ...
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