BCM Self-Diagnosis Function

BCM monitors conditions of the system components and its circuit with ignition switch turned to ON position. When an abnormality in the system occurs, the area where that abnormality lies is stored in the memory of EEPROM in BCM.
DTC can be checked in either one of following ways.
- DTC can be checked by SUZUKI scan tool (2) connected to DLC (1).
- DTC can be read from flashing pattern of theft deterrent light (3). In addition, when theft deterrent light is flashing for DTC outputting DTC is displayed on combinations meter (4) at the same time.
  
  Fig 1: Checking BCM Using Scan Tool
  Courtesy of SUZUKI OF AMERICA CORP.

BCM INPUT/OUTPUT TABLE

Control	Input	Output
Power door lock system	Key cylinder switch Manual door lock switch	Each door lock actuator
Keyless entry system	Key reminder switch Keyless entry receiver Each door switch	Each door lock actuator Turn signal and hazard warning relay Interior light
Keyless start system (Door lock function) (if equipped)	Keyless start control module	Each door lock actuator Turn signal and hazard warning relay Interior light
Rear wiper	Rear wiper INT switch Rear wiper ON switch Rear washer switch	Rear wiper relay
Panic alarm function	Panic alarm request signal	Headlight Tail light relay Horn relay
Combination meter	Lighting switch Brake fluid level switch Seat belt switch Generator Oil pressure switch Parking brake switch Dimmer switch (high beam) Each door switch TPMS receiver (if equipped)	Combination meter
Interior light	Each door switch Key reminder switch	Interior light Luggage room light
Warning buzzer	Key reminder switch Tail light switch Driver side door switch Keyless start control module (keyless start model)	Warning buzzer (located in combination meter)
Seat belt reminder (if equipped)	Seat belt switch signal Vehicle speed signal	Combination meter Warning buzzer (located in combination meter)
Tail light	Lighting switch	Tail light relay
DRL system (if equipped)	Lighting switch ECM (engine ON, OFF signal) Generator Parking brake switch	Combination meter Headlight low beam
Auto-on headlight system (if equipped)	Lighting switch Parking brake switch Auto-on headlight sensor	Tail light relay Headlight low beam relay or headlight high beam relay
Front fog light (if equipped)	Lighting switch Front fog light switch	Front fog light relay
Rear end door window defogger and door mirror heater	Rear end door window defogger switch (included in HVAC control module) Generator ECM (engine ON, OFF signal)	Rear end door window defogger relay Door mirror heater relay (if equipped)
Illumination control (if equipped)	Lighting switch Illumination control switch (MODE/ILL knob)	Transfer switch ESP® OFF switch HVAC control module Audio unit Front fog light switch Hazard warning switch Seat heater switch A/T select lever Remote audio control switch Cruise control switch Headlight washer switch
Door lock canceller	SDM (air bag deployment signal)	Each door lock actuator
Theft deterrent light	Key reminder switch	Theft deterrent light (located in HVAC control module)