Turbo

Engine Coolant Temperature Sensor:

The coolant temperature sensor is a thermistor (a device whose resistance changes with temperature) mounted in the cooling system passage of the intake manifold. Low temperature produces high resistance while high temperature produces low resistance.

The ECM supplies a voltage signal to the sensor and measures voltage variation. By measuring this variation, the ECM measures coolant temperature. This input is a factor in calculations involving these ECM controlled systems:

Fuel delivery
Electronic spark timing (EST)
Idle air control (IAC)
Turbocharger wastegate control
Canister purge control
AIR control
EGR control
EGR system diagnosis

Temperature (°C/°F) Resistance

0 / 32 5.6K ohms
20 / 68 2.5K ohms
40 / 104 1.2K ohms
60 / 140 600 ohms
80 / 176 320 ohms
100 / 212 180 ohms