Engine Temperature Control Module - GX33-, Checking: General Description

The Engine Temperature Control Module -GX33- combines several elements (thermostat, valves, coolant pump, etc.) into one component. Two mechanically connected rotary coolant valves (RCVs) are part of the module. The position of RCV 1 controls the coolant flow through the engine oil cooler, the cylinder head, and the main radiator. The RCV 2 controls the coolant flow through the cylinder block. The engine temperature can be adjusted to an optimum value regarding engine speed and load. In addition, the engine heat-up to optimum operating temperature is accelerated by the fact that the coolant circulation can be minimized. A position sensor detects the position of RCV 1. The monitor detects a stuck RCV. An emergency thermostat opens the main cooling circuit if the engine temperature is too high.

The Engine Temperature Control Module -GX33- contains the following components:

• Engine Temperature Control Actuator -N493-.

The Engine Temperature Control Module -GX33- components cannot be serviced separately, and they must be serviced as a unit.

Special tools and workshop equipment required 

• Multimeter.
• Wiring Diagram.
• Scan Tool.

Test requirements 

• Fuses OK.
• Battery voltage OK.
• Switch OFF all electrical and electronic accessories.
• Vehicles with automatic transmission, ensure the selector lever position is in "P".
• Vehicles with manual transmission, ensure the shifter lever position is in "N" with the parking brake applied.
• Observe all safety precautions: SAFETY PRECAUTIONS .
• View clean working conditions: CLEAN WORKING CONDITIONS .