Washer nozzle/washer nozzle hose heater, function

Function requirements, general

 "Engine running" or "drive train operational" signal on

 Outside temperature T < 5 °C

Washer nozzle/washer nozzle hose heater, general

The spray nozzle heater (R2/1) and the spray nozzle hose heater (R2/11) (with code (875) Heated windshield washer system) prevent the washing water from freezing in the washer nozzles and in the washer nozzle hose.

Function sequence for washer nozzle/washer nozzle hose heater

The front SAM control unit with fuse and relay module (N10/1) switches on the spray nozzle heater and the spray nozzle hose heater (with code (875) Heated windshield washer system) with the engine running and an outside temperature of T < 5 °C. The CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (with gasoline engine) sends the signal "Engine running" or "Drivetrain operational" via chassis CAN (CAN E) (up to 28.2.13) or chassis CAN 1 (CAN E1) (as of 1.3.13) to the front SAM control unit. The outside temperature is detected by the outside temperature sensor (B14). The front SAM control unit reads in the signal of the outside temperature sensor, calculates the outside temperature and sends this via interior CAN (CAN B) to the instrument cluster (A1). The instrument cluster calculates the outside temperature to be displayed, taking the vehicle speed and the heat dissipated from the engine into account, and sends this via interior CAN to the front SAM control unit. The front SAM control unit evaluates all relevant data and actuates the spray nozzle heater and spray nozzle hose heater directly. If the outside temperature increases to T > 8 °C, the spray nozzle heater and the spray nozzle hose heater are switched off.

 If the front SAM control unit cannot receive an outside temperature value from the instrument cluster, it calculates the outside temperature itself.