Nissan Xterra. Manual - part 384

EXL-24

< SYSTEM DESCRIPTION >

COMBINATION SWITCH READING SYSTEM

COMBINATION SWITCH READING SYSTEM

System Diagram

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System Description

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OUTLINE

• BCM reads the status of the combination switch (light, turn signal, wiper and washer) and recognizes the

status of each switch.

• BCM has a combination of 5 output terminals (OUTPUT 1 - 5) and 5 input terminals (INPUT 1 - 5) and reads

a maximum of 20 switch states.

COMBINATION SWITCH MATRIX

Combination switch circuit

Combination switch INPUT-OUTPUT system list

AWMIA1250GB

System

INPUT 1

INPUT 2

INPUT 3

INPUT 4

INPUT 5

OUTPUT 1

—

FR WASHER

FR WIPER LOW

TURN LH

TURN RH

OUTPUT 2

FR WIPER HI

—

FR WIPER INT

PASSING

HEADLAMP 1

OUTPUT 3

INT VOLUME 1

RR WASHER

—

HEADLAMP 2

HI BEAM

AWMIA1251GB

COMBINATION SWITCH READING SYSTEM

EXL-25

< SYSTEM DESCRIPTION >

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COMBINATION SWITCH READING FUNCTION

Description

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

NOTE:

BCM reads the status of the combination switch at 60 ms intervals when BCM is controlled at low power

consumption control mode.

• BCM operates as follows and judges the status of the combination switch.

- It operates the transistor on OUTPUT side in the following order: OUTPUT 1 

→ 2 → 3 → 4 → 5, 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.

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) is turned ON

OUTPUT 4

RR WIPER INT

INT VOLUME 3

AUTO LIGHT

—

TAIL LAMP

OUTPUT 5

INT VOLUME 2

RR WIPER ON

—

FR FOG

—

System

INPUT 1

INPUT 2

INPUT 3

INPUT 4

INPUT 5

JPMIA0609GB

JMMIA0326GB

EXL-26

< SYSTEM DESCRIPTION >

COMBINATION SWITCH READING SYSTEM

• The circuit between OUTPUT 4 and INPUT 5 is formed when the TAIL LAMP switch is turned ON.

• 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, TAIL LAMP) 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.

• 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.

WIPER INTERMITTENT DIAL POSITION SETTING (FRONT WIPER INTERMITTENT OPERATION)

BCM judges the wiper intermittent dial 1 - 7 by the status of INT VOLUME 1, 2, and 3 switches.

AWMIA1252GB

AWMIA1253GB

COMBINATION SWITCH READING SYSTEM

EXL-27

< SYSTEM DESCRIPTION >

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Component Parts Location

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Wiper intermittent

dial position

Intermittent

operation delay 

interval

INT VOLUME switch ON/OFF status  

INT VOLUME 1

INT VOLUME 2

INT VOLUME 3

1

Short

↑

↓

Long

ON

ON

ON

2

ON

ON

OFF

3

ON

OFF

OFF

4

OFF

OFF

OFF

5

OFF

OFF

ON

6

OFF

ON

ON

7

OFF

ON

OFF

1.

BCM M18, M19, M20 (view with low-
er instrument panel LH removed)

2.

Combination switch (lighting and 
turn signal switch) M28

3.

Combination switch (wiper and 
washer switch) M28

ALMIA0409ZZ