Electric Cooling Fan

WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2004 Mercedes-Benz CLK55, 2004 Mercedes-Benz CLK500, 2004 Mercedes-Benz CLK320, 2004 Mercedes-Benz C320, and 2004 Mercedes-Benz C32. However, it is still accessible from the selected car via links, so may be relevant.

The engine has a large cooling system with an electronically controlled engine cooling fan. The fan draws air through the radiator from behind the radiator. The engine cooling fan speed is based on a signal from ECM. ECM selects fan speed based on inputs from Engine Coolant Temperature (ECT) sensor and pressure in the air conditioning system. The fan is controlled electronically via a signal from the ECM to the Cooling Fan With Integrated Control Unit. Cooling fan control unit is OBDII compatible and defects are stored as DTCs in ECM memory. For DTC repair procedures, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

The A/C pressure sensor provides information to ECM concerning pressure changes on the high-pressure side. Depending on the pressure the ECM activates the engine cooling fan at high/low speed and can also shut off the A/C compressor. Cooling fan conrol module receives a signal from the ECM about which speed the engine cooling fan should run.