Cabin temperature sensor

This sensor combines an air humidity and a temperature sensor in the same package. The sensor location is designed to provide an average temperature for the whole cabin, and includes a small blower motor. The direction of the flow of this blower is such that air is sucked into the sensor input.

The sensor is located under the steering column:

It is installed behind the lower trim panel of the steering column:

  • Part number: 8M2T-8B506-AB, -AC or 9M2T-8B506-AA, -AB, -AC
  • FINIS ordering number: 1764020
  • Price (new at a Ford dealer): approx. 80,- €

Pin Cable color Description Function
1 PWR +12V supply voltage
2 - - -
3 GND Ground
4 TEMP SIG+ Signal, Temperature Sensor
5 TEMP SIG- Signal, Temperature Sensor
6 HUMIDITY SIG Signal, Humidity Sensor

This sensor is composed of two parts, a temperature sensor and a blower motor:

This is a common problem. It is easy to hear when the ignition switch is ON, but the engine is not started. The culprit is the temperature/humidity sensor (the blower inside). The fan prop is only attached to the motor axle (stator). The motor has three connectors, so its likely possible to control its speed. The connector for the speed controller is located in the small temperature sensor board. Likely due to being located in the trim of the steering column, the rattling is intensified, because when the sensor is disassembled, the noise is almost imperceptible. I could not find any bearing damage, so likely the noise is produced by the structure of the motor itself. Since this is a sintered bearing, it is unlikely that any lubricant is used at all.

To remedy the noise, the best is to buy a new part, since used parts will likely have the same problem or develop it in the short term future.

Alternatively, the whole thing can be built as described here: Lauten Innenraum-Klimasensor ruhig machen

  • en/artikel/innenraum-temperatursensor/start.txt
  • Last modified: Fri. 24.05.2019 14:48
  • by jphid