Principles of Operation: Notes

The SJB  monitors the headlamp switch position by sending voltage signals on multiple circuits to the headlamp switch. There is one circuit for each headlamp switch position. At any given time, one of the signal circuits is switched to ground.

If the SJB  does not detect any of the inputs to the headlamp switch are active (switched to ground) for 5 seconds, the SJB  turns on the exterior lights and keeps them on for 10 minutes after the ignition switch is turned off (or 10 minutes from the time the SJB  does not detect any headlamp switch input if the ignition switch was already off).

Additionally, if the SJB  detects multiple circuits short to ground, the SJB  implements a planned strategy depending on the multiple inputs received. Based on the multiple inputs received, the autolamps, the headlamps and/or parking lamps are turned on.

If either situation occurs, the SJB cannot  be ruled immediately as being at fault. This is normal behavior of the SJB  design as it has detected a fault with the inputs from the headlamp switch.

The SJB  monitors the multifunction switch for a flash-to-pass or high beam request. There are 2 voltage reference circuits which monitor this. When the multifunction switch is in the FLASH-TO-PASS or HIGH BEAM position, the voltage signal is routed to ground.

When the SJB  receives an input requesting the headlamps on, the SJB  supplies voltage to the low beams. If the low beams are on and the SJB  receives a request for high beams (or a flash-to-pass request), the SJB  energizes an internal relay which routes voltage to the headlamps.