Wipers/Washers - Rain Sensor Function/Limitations
NO: 36-38DATE: 10-27-2004
MODEL: S60/V70/XC70/S80/XC90 (MY03-04).
SUBJECT: Rain Sensor Function.
REFERENCE: Owners manual, VADIS - Design and Function, Sect 36, UEM.
This Tech Note supersedes the previous TNN 36-38 dated 2-4-03. Please update your files.
Description
This Tech Note is intended to provide functional features, how to operate and what the limitations of the Rain Sensor are.
Rain Sensor Function
The rain sensor is a very convenient feature when used as intended.
However, its operation can be confusing as it has been reported in its first two model years (MY2003-2004). It also has some limitations and some important functionality features.
In order to achieve high customer satisfaction on vehicles equipped with rain sensors, it is very important that customers driving a rain sensor equipped car of MY2003-04 understand how to operate and are aware of the limitations of the feature.
1) Activation
On MY 2003-04 cars, the rain sensor replaced the intermittent function. The rain sensor function is activated by putting the column stalk in the rain sensor position (similar to the intermittent wiping position on cars without rain sensor). This may be confusing to owners with previous Volvo experience. It also limits the performance and functionality of the wiper system when the rain sensor has not been activated properly.
2) De-activation and re-activation - Important!
The rain sensor must be re-activated each time the ignition has been turned off.
On MY 2003-2004 cars this is done by moving the column stalk to another position and back to the rain sensor position. If the column stalk on a MY 2003-2004 car with rain sensor has been left in the rain sensor position, there will be no wiper function at all when the car is started. This could be confusing since there is no indication of the sensor being on or off.
To directly activate the wipers the stalk must be moved to one of the two continuous-wiping positions. To reactivate the rain sensor, the stalk must be moved to any other position and back to the rain sensor position.
A customer with a rain-sensor-equipped car should be aware of this, preferably make a habit of returning the column stalk to the 0 position each time he or she leaves the car, to make sure the rain sensor is correctly reactivated at the next time of use.
3) Sensitivity and thumbwheel settings
The rain sensor is sensitive to lighting conditions, and the sensitivity may change at dusk/dawn and at night. The thumbwheel sensitivity adjustment is there to compensate for this, as well as to adjust to different customer preferences.
4) Confirmation wiper strokes
Upon activation the rain sensor always immediately makes one stroke of the wipers to confirm the activation. Also when the sensitivity is increased by turning the thumbwheel clockwise there will always be one immediate stroke to help the driver quickly clear the field of view.
5) Limitations - Important!
The rain sensor function might not work properly under following conditions:
^ Worn wiper blades.
^ Icing, salt or other substances smearing on the windshield.
^ Dirt, scratches, or other items in the sensor's field of view.
The critical area is the sensor area on the windshield in front of the inner rear view mirror foot, see pictures of location of the sensor.
Location of the sensor
The rain sensor is located in front of the rear view mirror on the inner side of the windshield.
Important service note:
When replacing the windshield on a rain-sensor-equipped car it is very important that the rain sensor is located at the exact correct distance from the windshield inner surface. It is recommended to use an original replacement windshield with rain sensor bracket. Extreme precision is needed when transferring the rain sensor bracket to a new windshield if an aftermarket windshield is used.