Main Beam, Xenon, Us/Ca/JP: Notes

Fig 1: Identifying Main Beam Communication Diagram - Xenon (US/CA/JP)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Main beam is turned on by moving the dipswitch on the steering column towards the steering wheel rim when the light switch is in position 2 and the ignition is ON. DICE activates the main beam relay (8a).

To enable DICE to determine what position (0-1--2) the light switch (10) is set to, the control module uses bus information from TWICE and its own pins 39 and 15.

TWICE monitors the parking lights and sends information on the bus (Rear light Left ON/OFF and Rear light Right ON/OFF). The ON message corresponds to switch position 1 and the OFF message corresponds to position 0 or 2.

To enable DICE to determine the position setting, it uses pins 39 and 15. DICE pin 39 is connected to light switch pin 10, which corresponds to position 0. DICE pin 15 is connected to light switch pin 11, which corresponds to position 2.

B+ is fed from connection 11 on the light switch (10) to pin 15 on the control module. When the switch (215) is turned on, B+ voltage will be fed from pin 6 to pin 41 on DICE. DICE turns on the main beam when pin 11 on the control module grounds pin 5 on the main beam relay (8). With the relay closed, B+ voltage will be fed via fuse 12 to pin 2 on the right-hand headlamp and via fuse 10 to pin 2 on the left-hand headlamp, whereby the solenoids will drop the xenon lamp screens.

MIU (540) is powered from fuse 10 so that a lamp 47g on MIU comes on to indicate that the main beam is on.

IMPORTANT: When changing a bulb, select a new bulb of the correct rating to prevent the components being damaged.