Coolant temperature sensor ME-SFI - fault code description
Coolant temperature sensor, plausibility
1
Fault code
( Readout on generic scan tool)
P202D (P0115)
2
Fault storage
Actuation of the indicator lamp
Engine diagnosis (EURO3/4) or
CHECK ENGINE (MIL)
after expiry of test duration and fault
following two successive driving cycles with faults
3
Checking frequency
Continuous
4
Checked signal or status
Temperature increase after a cold start
5
Fault setting conditions
The temperature increase after the cold start is compared with a stored temperature model (characteristic). Fault if the differentiate between the temperature model and the measured temperature is greater than about 20°C.
Depending on the starting temperature and engine speed, at least 10 to 20°C must be reached after 40 to 600 seconds, otherwise the coolant temperature sensor is defective or the coolant thermostat sticks open
6
In the event of a fault, driving can continue using a substitute value from the temperature model. The system will then change back over to the signal from the coolant temperature sensor once the signal becomes plausible again.