Disconnect a wire from the sensor of temperature and connect between its plug and "weight" an ohmmeter. At the cold engine resistance of the sensor should be rather big. Start the engine. In process of engine warming up resistance of the sensor of temperature should decrease in inverse proportion to engine temperature.

Cause of defect can be and the remote thermometer. For check disconnect a wire, and at the switched-off ignition connect it to "weight". Include ignition. The arrow of the remote thermometer should rise at once in the situation "Heiss" (hotly). Switch off ignition.

Prevention Connect a wire for check only for short time not to damage the remote thermometer.