Combination Switch Reading Function

Description

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

Fig 1: Combination Switch Outputs Voltage Waveform

Courtesy of NISSAN MOTOR CO., U.S.A.

• BCM operates as follows and judges the status of the combination switch.
  • It operates the transistor on OUTPUT side in the following order: OUTPUT 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.
  Fig 2: Output Voltage Waveform

  Courtesy of NISSAN MOTOR CO., U.S.A.

  Operation Example

  In the following operation example, the combination of the status signals of the combination switch is replaced as follows: INPUT 1 - 5 to "1 - 5" and OUTPUT 1 - 5 to "A - E".

  Example 1: When a switch (TAIL LAMP switch) is turned ON

• The circuit between OUTPUT 4 and INPUT 5 is formed when the TAIL LAMP switch is turned ON.
  Fig 3: Combination Switch Circuit Diagram - When Switch (Tail Lamp Switch) Turned ON

  Courtesy of NISSAN MOTOR CO., U.S.A.
• BCM detects the combination switch status signal "5D" when the signal of OUTPUT 4 is input to INPUT 5.
• BCM judges that the TAIL LAMP switch is ON when the signal "5D" is detected.

Example 2: When some switches (TURN RH switch, TAIL LAMP switch) are turned ON

• The circuits between OUTPUT 1 and INPUT 5 and between OUTPUT 4 and INPUT 5 are formed when the TURN RH switch and TAIL LAMP switch are turned ON.
  Fig 4: Combination Switch Circuit Diagram - When Switches (Turn RH Switch, Tail Lamp Switch) Turned ON

  Courtesy of NISSAN MOTOR CO., U.S.A.
• BCM detects the combination switch status signal "5AD" when the signals of OUTPUT 1 and OUTPUT 4 are input to INPUT 5.
• BCM judges that the TURN RH switch and TAIL LAMP switch are ON when the signal "5AD" is detected.