Coolant temperature sensor
The engine requires up to 80% extra fuel for a cold start. We can record this in the warmup enrichment menu. If we did not have an engine temperature sensor, we would not be able to add extra fuel. We want to have a slightly richer mixture with a cold engine and to have the speed slightly higher. To prevent stopping and so that the engine runs nicer. Registration of the engine temperature is therefore important.
Warmup Enrichement Curve
In addition, the coolant temperature sensor can detect a too high temperature and switch on a radiator fan. Sometimes the engine cools down too far on the highway. Then the thermostat is broken. This is immediately visible in the EFIgnition software.
De temperatuur aanwijzing in TunerStudio
The sensor contains an NTC Thermistor. This means that the resistance changes with increasing or decreasing the temperature. The EFIgnition registers this resistance and converts it into a temperature.
Because it is possible to program the characteristic of the sensor in the software, any sensor can be used. But it must be a double-pole sensor so that the sensor does not make electrical contact with the motor. Some Volvo (740) sensors are double pole but still make contact with the engine. These sensors cannot be used as they will make a "ground-loop".