Dipped beam, detailed description: Limp-home

Dipped beam is lit if the following faults occur:

Fig 1: Identifying Daytime Running Lights (DRL)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

• UEC has no bus communication and ignition is on, lead from ISM (Ignition Switch Module) to UEC.
• Fault in UEC microprocessor.

Dipped beam is lit in the following cases:

• UEC receives bus message "Dipped beam, button active ON".
• BCM detects that the light switch is faulty.