1.10.1.1 Circuit continuity check

P0117 (TMEmin), P0118 (TMEmax), P0119 (TMEnpl) 

The circuit continuity check compares the measured engine coolant temperature with an upper and a lower threshold to detect short circuits.

If the measured engine coolant temperature sensor voltage exceeds the upper calibration limit for a calibrated period of time, a short circuit to ground is detected and a TMEmax fault will be set.

If the measured engine coolant temperature sensor voltage lies below the lower calibration limit for a calibrated period of time, a short circuit to battery or a broken wire is detected and a TMEmin fault will be set.

An intermittent contact may result in frequent jumps of the measured engine coolant temperature signal. A signal jump is detected by evaluation of the difference between the measured engine coolant temperature and the filtered engine coolant temperature. If this difference exceeds a calibrated value a "jump-detectedtimer" with a calibrated time length is started and retriggered every time the difference exceeds again the calibrated value (multiple jumps).

If the overall time of the retriggered and as a result continuously running "jump-detected-timer" exceeds a calibrated period of time, an intermittent contact is detected and a TMEnpl fault will be set.