SLK 350 (171.458) V6-3.5L (272.969) (2009)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
GF07.04-P-6040MIK Coolant Temperature Sensor, Component Description
- refinement package
- as of model year 09
Component Identification
Location
The temperature sensor is located at the rear on the left cylinder head.
Task
The temperature sensor detects the coolant temperature and transmits a corresponding voltage signal to the ME-SFI [ME] control unit (N3/10).
Design
The temperature sensor consists of a very rapidly responding NTC resistor and a 2-pin plug connection. The bottom part of the housing which is plugged
in the cylinder head consists of meta
Function
The NTC resistor integrated in the temperature sensor alters its electrical resistance in line with the coolant temperature. The ME-SFI [ME] control unit
applies a sensor voltage of 5 V and evaluates the signal voltage in accordance with the coolant temperature.
The signal voltage is plausible between 0.1 V to 4.93 V, otherwise a fault is identified and a substitute value taken by the ME-SFI [ME] control unit from
a stored temperature model.
NTC
NTC means " Negative Temperature Coefficient", which means: the electrical resistance reduces for an increasing temperature (NTC thermistor).
Diagnosis
The NTC resistor is supplied by the ME-SFI [ME] control unit via a series resistor (1470 ohms ±1% ) with 5 V. Following a short-circuit to battery
voltage or sensor voltage without series resistor, the temperature sensor is defective.