Outside Temperature Sensor

WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Outside Temperature Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

The outside temperature sensor supplies the engine control module (ECM) with a signal describing the outside temperature.

This signal is used to disable certain diagnostic functions when the temperature is under 7°C.

The following diagnostic functions are disabled:

leak diagnostic
pulsed secondary air injection (PAIR) system diagnostic
misfire diagnostic
boost pressure control diagnostic.
mass air flow (MAF) sensor, faulty signal.

The sensor incorporates a temperature-sensitive resistance with a negative temperature coefficient (NTC). The sensor is supplied with a stabilized voltage of 5 V. The voltage across the sensor is a function of the outside temperature and, therefore, of sensor resistance. Voltage can be between 0 V and 5 V.

If the signal from the outside temperature sensor is faulty or missing the engine control module (ECM) adopts substitute values.

The outside temperature sensor is located under the bumper on the left-hand side.