(2) Temperature Sensors?

[tomd365]

My M30 has (2) temp sensors in the thermostat housing. I am guessing one if coolant temp (the gauge) and one is for engine temp for the ECM. Do I have this correct? Also, if the temp sensor for the ECM is bad, would it throw a code? The mileage has dropped lately and the power is off when the engine is warm. I am wondering if I could be running in "cold engine" mode all of the time. The coolant temp gauge is straight up as always. Any thoughts???

[632 Regal]

in the Bently manual there is ohm readings for the sensors instead of just replacing them. Did you try to reboot the computer yet?

[gale]

The sensor closest to the head (usually blue) is the DME temp sensor. It should read approx. 2100 ohms cold, 270 ohms hot. It will throw a code if it failed but if it's a bit low, say 170 ohms hot, it won't throw a code. Below 100 ohms hot -- definitely replace it. The other sensor is for the temp gauge.

[tomd365]

Thanks. I checked the one with the blue plug and it was 210 ohms hot. A little below the Bentley's spec. I am going to check it cold also and see where it is. I am not sure what is going on with the engine. It just doesn't have the smoothe power when it is warmed up. Cold, the engine pulls well and feels powerful. Warm, it just revs and moves out like an old man's sedan. More investigation to do...