Operation CHARM: Car repair manuals for everyone.

Thermostat Monitoring



Thermostat Monitoring

General description
After engine start and under the conditions:
- no hot engine
- ambient temperature within range
- normal driving - average vehicle speed > 25km/h
- sufficient mass air flow

an increase of the coolant system temperature will be expected.

Monitor structure
If the engine coolant temperature does not reach a certain value under normal driving conditions, the coolant system is defective.







flow chart: