Hazard Warning Switch: Description and Operation

Hazard Warning Lights Switch (25)







Main task
Used to activate hazard warning lights and to indicate that they are active. BCM transmits the function status on the bus.

Type
The button is single-pin, has a return spring and closes to ground when depressed. The button also contains an indicator lamp that is grounded internally.

Connection
The lead to the button is supplied 10.2 V via a BCM integrated resistor of 1.5 k ohm. Control module inputs are digital; voltage over 2V is interpreted as an open circuit while voltage lower than 2V is interpreted as closed.

Diagram:

The indicator lamp in the button is supplied battery voltage from BCM in order to light.

Switch mounted in ACC (216):

Pin No. 15-26:

Switch mounted in MCC (504):

Pin No. 2-19: