Coolant temperature: Notes

The coolant temperature gauge provides the driver with information on the engine coolant temperature. It is supplied with power from the main instrument unit and is also controlled from there.

The temperature sensor is connected to the engine control module, which continuously sends information on the coolant temperature to the bus. The main instrument unit receives information on the coolant temperature via the bus.

Fig 1: Identifying Communication Diagram - Coolant Temperature

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Identifying Communication Circuit Diagram - Coolant Temperature (1 Of 2)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 3: Identifying Communication Circuit Diagram - Coolant Temperature (2 Of 2)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The coolant temperature gauge's scale is divided into 5 fixed breakpoints. The main instrument unit is programmed to move the gauge needle to the fixed breakpoints at certain specific temperatures to give a steady reading at normal coolant temperatures.

The following breakpoints are programmed in the main instrument unit (factory setting):

COOLANT TEMPERATURE SPECIFICATION

Coolant temperature
Gauge needle:	Petrol cars	Diesel cars
-out of "blue" zone	50°C	50°C
-into "horizontal" position	83°C	80°C
-out of "horizontal" position	115°C	110°C
-into "red" zone	129°C	119°C