System Description

SYSTEM DIAGRAM 

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OUTLINE 

• BCM reads the status of the combination switch and recognizes the status of each switch.
• BCM has a combination of 6 input terminals (INPUT 1 - 6) and 6 output terminals (OUTPUT 1 - 6), reads a maximum of 22 switch states and 6 check diode states.

COMBINATION SWITCH MATRIX 

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System	INPUT 1	INPUT 2	INPUT 3	INPUT 4	INPUT 5	INPUT 6
OUTPUT 1	Check diode 1	INT volume 1	Front washer switch	Front wiper LO	INT volume 2	Front wiper OFF
OUTPUT 2	High beam switch	Check diode 2	Rear washer switch	Front wiper HI	INT volume 3	Front wiper MIST
OUTPUT 3	Passing switch	Low beam switch	Check diode 3	Front wiper INT	Rear wiper INT	-
OUTPUT 4	-	AUTO light switch	Turn signal LH	Check diode 4	Rear wiper ON	-
OUTPUT 5	Front fog switch	Tail lamp switch	Turn signal RH	Light OFF switch	Check diode 5	-
OUTPUT 6	-	-	-	-	-	Check diode 6

COMBINATION SWITCH READING FUNCTION 

Description 

• BCM reads the status of the combination switch at 10 ms intervals normally.

  Courtesy of NISSAN

• BCM operates as follows and judges the status of the combination switch.
  • It operates the transistor on INPUT side in the following order: OUTPUT 6-> 5 -> 4 -> 3 -> 2 -> 1, and outputs voltage waveform.
  • The voltage waveform of OUTPUT corresponding to the formed circuit is input into the interface on INPUT side if any (1 or more) switches are ON.
  • It reads this change of the voltage as the status signal of the combination switch.

    Courtesy of NISSAN

Operation Example 

In the following operation example, the combination of the status signals of the combination switch is replaced as follows: INPUT 1 - 6 to " - " and OUTPUT 1 - 6 to " - ". Example 1: When a switch (Turn signal RH) is turned ON

• The circuit between INPUT 3 ( ) and OUTPUT 5 ( ) is formed when the Turn signal RH is turned ON.

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  NOTE: AUTO light switch is not applicable. (For Canada models)
• BCM detects the combination switch status signal " " when the signal of INPUT 3 is input to OUTPUT 5.
• BCM judges that the Turn signal RH is ON when the signal " " is detected.

Example 2: When some switches (Front fog switch, Turn signal RH) are turned ON

• The circuits between INPUT 1 ( ) and OUTPUT 5 ( ) and between INPUT 3 ( ) and OUTPUT 5 ( ) are formed when the Front fog switch and Turn signal RH are turned ON.

  Courtesy of NISSAN

  NOTE: AUTO light switch is not applicable. (For Canada models)
• BCM detects the combination switch status signal " " when the signals of INPUT 1 and INPUT 3 are input to OUTPUT 5.
• BCM judges that the Front fog switch and Turn signal RH are ON when the signal " " is detected.

WIPER INTERMITTENT DIAL POSITION (WITH WIPER INTERMITTENT DIAL POSITION) 

BCM judges the wiper intermittent dial 1 - 5 by the status of INT volume 1, 2 and 3 switches.

Wiper Intermittent Dial Position	Switch Status
INT volume 1	INT volume 2	INT volume 3
1	ON	ON	OFF
2	ON	OFF	OFF
3	OFF	OFF	OFF
4	OFF	OFF	ON
5	OFF	ON	ON