Wipers / washers
The right-hand control stalk is moved downwards through three positions to operate the windshield wipers. The steering wheel module (SWM) (3/254) transmits information to the central electronic module (CEM) (4/56) about the selected position using serial communication. The central electronic module (CEM) then activates the relay which supplies the wiper motor (6/1) with power in position 1. If high speed wiping is selected, the relay is also activated to power the motor in position 2.
The central electronic module (CEM) receives a signal from the motor when the wipers are in the parked position so that the wipers can be stopped in the correct position.
For intermittent wiping, the process is the same as for low speed, but the time between each stroke is set using the ring on the control stalk to one of eight positions between 1 and 27 seconds. The central electronic module (CEM) controls this once it has received information about intermittent wiping from the steering wheel module (SWM) via serial communication.
The windshield and headlamps are washed when the right-hand control stalk is moved towards the steering wheel. The steering wheel module (SWM) transmits information to the central electronic module (CEM) to activate washing via serial communication. The central electronic module (CEM) activates an internal relay which powers the pump motor (6/127) and the headlamp wiper motors (6/3-4) (S80 and R-models only).
For other models, the central electronic module (CEM) activates the relay (2/182) which powers high-pressure cleaning (6/104).
The central electronic module (CEM) receives a signal from the level sensor (7/5) in the windshield washer reservoir so that it can check the windshield washer reservoir level. The switch in the level sensor closes if the level falls below one liter. The central electronic module (CEM) sends the signal to Driver information module (DIM) (5/1) via the controller area network (CAN). The driver information module (DIM) displays a text message for approximately 10 seconds indicating that the windshield washer fluid needs to be topped up.
The tailgate wiper (6/32) (V70/XC70/XC90) is controlled by the rear electronic module (REM) (4/58). The rear electronic module (REM) receives a signal from the steering wheel module (SWM) via the central electronic module (CEM). The rear electronic module (REM) then powers the relay to start the tailgate wiper. The tailgate wiper is powered by the rear electronic module (REM).
The tailgate wiper can be programmed so that it is not activated if the windshield wipers are on and back-up (reverse) gear is selected.
Rear windshield cleaning is activated when the right-hand control stalk is pushed away from the steering wheel. The steering wheel module (SWM) transmits information to the central electronic module (CEM) to activate tailgate washing via serial communication. The central electronic module (CEM) activates the relay to power the pump motor (6/127). At the same time the rear electronic module (REM) activates the tailgate wiper.
The wipers only operate at low speed if there is a fault in the control area network (CAN). If this is the case, the central electronic module (CEM) receives a directly connected signal from the steering wheel module (SWM).
There is no Limp Home function for the rear windshield washer and wiper.