BCM Self-Diagnosis Function

WARNING: This page is about a different car, the 2006 Suzuki XL-7. However, it is still accessible from the selected car via links, so may be relevant.

BCM diagnoses conditions of the system component parts and its circuit (whether or not there is any abnormality) all the time and indicates the results (warning of abnormality occurrence and DTC) through the "Clock/Temp. display" as described below.

When an abnormality in the system is detected, "Clock/Temp. display" (1) keeps flashing and the area where that abnormality lies is stored in the memory of EEPROM in BCM.

Fig 1: Identifying "Clock/Temp. Display"
Courtesy of SUZUKI OF AMERICA CORP.
When Diagnosis switch terminal (3) of BCM monitor connector is grounded, the abnormal area is output as DTC
If any malfunction code is existing, "Clock/Temp. display" (1) indicates DTCs in number order at every 3 seconds.

Fig 2: Identifying "Clock/Temp. Display", Diagnosis Switch Terminal, Service Wire, Body Ground & Blower Unit
Courtesy of SUZUKI OF AMERICA CORP.

BCM SELF-DIAGNOSIS FUNCTION CHART

System Condition		Clock/Temp. Display
System Condition		Diag. Switch terminal is not grounded	Diag. Switch terminal is grounded
In good condition at present	No trouble in the past	Turn ON	DTC 12
In good condition at present	Trouble occurred in the past	Turn ON	History DTC
Abnormality exists at present	No trouble in the past	Keep flashing	Current DTC
Abnormality exists at present	Trouble occurred in the past	Keep flashing	Current and history DTCs

BCM input / output table

BCM INPUT / OUTPUT

System	Input	Output
Power door lock	Key cylinder switch Manual door lock switch	Driver side door lock actuator Except driver side door lock actuator
Keyless entry system	Key reminder switch Keyless entry receiver Driver side door switch	Driver side door lock actuator Except driver side door lock actuator Turn signal and hazard warning relay Interior room lamp Keyless entry receiver
Lighting	Headlight switch Tail light switch Auto light switch Front fog light switch Auto light sensor Illumination controller Generator L terminal	Headlight Tail light DRL Front fog light Illumination lamp
Rear wiper and washer	Rear wiper INT switch Rear wiper switch Rear washer switch	Rear wiper motor Rear washer motor
Combination meter	Headlight switch Tail light switch Auto light switch Brake fluid level switch Charging system monitor switch Washer level switch TCM (O/D OFF switch, transmission range switch, A/T mode switch) (A/T only)	Combination meter
Interior light	Driver side door switch Except driver side door switch Key reminder switch	Interior light
Warning buzzer	Key reminder switch Headlight switch Tail light switch Driver side seat belt switch Driver side door switch	Warning buzzer (located in BCM)