05 freightliner m2 water temp gauge not working

• 2022-10-18

When the 05 freightliner m2 water temp gauge not working , the temperature signal displayed during the cold start is still the temperature signal during the hot start . The ECU can not provide the signal of too rich mixture , and can only supply the thinner mixture of the engine (the signal during the hot start) , so it is difficult to start the engine cold start . In this case , check whether the water temperature sensor plug contacts normally or replace the water temperature sensor.

For example, reading the data of the vehicle's static engine (refers to the cold vehicle) , it is found that the coolant temperature output by the engine ECU is 105 ℃, while the actual temperature of the engine at this time (set as the temperature in winter) is only 1 ℃. Obviously , the water temperature signal received by the engine ECU is wrong , indicating that there is a problem with the water temperature sensor .

It should be noted that the 05 freightliner m2 water temp gauge sensor is a kind of electronic original device on the automobile circuit . If this device is broken , there is little room for repair , and it can only be replaced . If you want to test it , the simple way is to put the water temperature sensor into the heating cup for heating (pay attention not to submerge the plug part) , and use the "resistance gear" of the multimeter to measure it . When the temperature rises , the resistance should be small . If there is no change , it proves that this thing is broken .

If this component is detected with a scan tool , it needs to be detected when the vehicle is cold . The function of the water temperature sensor is to convert the cooling water temperature into an electrical signal . After input to the ECU, there are: 1. Correct fuel injection quantity . Increase the injection quantity when the temperature is low . 2. Correct the ignition advance angle . Increase the ignition advance angle at low temperature, and delay it at high temperature to prevent deflagration . 3. Affect idle speed control valve; At low temperature, ECU controls the action of idle control valve according to the water temperature sensing signal to increase the speed.