Electrical System Indicator

Instrument panel cluster illuminates SERVICE VEHICLE SOON indicator when the following occurs:

• Body Control Module (BCM) detects certain malfunctions in lighting system or horn system.
• PCM detects certain non-emissions related malfunctions. BCM receives a class 2 message from PCM requesting illumination.

BCM sends a message to instrument panel cluster via Serial Peripheral Interface (SPI) requesting illumination. BCM also sends a class 2 message to radio in order to activate an audible warning.