Diagnostic Trouble Code (DTC) Information CEM-Dd40

Condition

The humidity sensor is connected to Central electronic module (CEM) and senses humidity in the passenger compartment. Information is sent from Central electronic module (CEM) to Climate control module (CCM) and is the basis for how the climate control module counteracts mist on the windows.

The diagnostic trouble code (DTC) is stored if the control module detects that:

The air humidity sensor sends error message.

The control module's test for the diagnostic trouble code (DTC) starts in the event of:

Ignition switch position I and II.

Fig 1: Identifying Humidity Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

Substitute Value

None

Possible Source

Internal fault in air humidity sensor.

Fault symptom[s]

Defog/defrost/Windshield defog/defrost/Does not work
Defog/defrost/Windshield defog/defrost/Slow to clear/uneven clearing