The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.

WARNING:

●

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

●

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

●

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.

BCM (BODY CONTROL MODULE)

BCS-3

BCS

2007 Pathfinder

BCM (BODY CONTROL MODULE)

PFP:284B2

System Description

EKS00G0M

BCM (body control module) controls the operation of various electrical units installed on the vehicle.

BCM FUNCTION

BCM has a combination switch reading function for reading the operation of combination switches (light, wiper
washer, turn signal) in addition to the function for controlling the operation of various electrical components.
Also, it functions as an interface that receives signals from the A/C control unit, and sends signals to ECM
using CAN communication.

COMBINATION SWITCH READING FUNCTION

Description

●

BCM reads combination switch (light, wiper) status, and controls various electrical components accord-
ing to the results.

●

BCM reads information of a maximum of 20 switches by combining five output terminals (OUTPUT 1-5)
and five input terminals (INPUT 1-5).

Operation description

●

BCM activates transistors of output terminals (OUTPUT 1-5) periodically and allows current to flow in
turn.

●

If any (1 or more) of the switches are turned ON, circuit of output terminals (OUTPUT 1-5) and input ter-
minals (INPUT 1-5) becomes active.

●

At this time, transistors of output terminals (OUTPUT 1-5) are activated to allow current to flow. When
voltage of input terminals (INPUT 1-5) corresponding to that switch changes, interface in BCM detects
voltage change and BCM determines that switch is ON.

BCM - Operation table of combination switch

●

BCM reads operation status of combination switch by the combination shown in the following table.

LIIA0757E

BCS-4

BCM (BODY CONTROL MODULE)

2007 Pathfinder

NOTE:
Headlamp has a dual system switch.

Example operation: (When lighting switch 1st position turned ON)

●

When lighting switch 1st position is turned ON, contact in combination switch turns ON. At this time if
OUTPUT 4 transistor is activated, BCM detects that voltage changes in INPUT 5.

●

When OUTPUT 4 transistor is ON, BCM detects that voltage changes in INPUT 5, and judges lighting
switch 1st position is ON. Then BCM sends tail lamp ON signal to IPDM E/R using CAN communica-
tion.

●

When OUTPUT 4 transistor is activated again, BCM detects that voltage changes in INPUT 5 and rec-
ognizes that lighting switch 1st position is continuously ON.

SKIA4959E

BCM (BODY CONTROL MODULE)

BCS-5

BCS

2007 Pathfinder

NOTE:
Each OUTPUT terminal transistor is activated at 10ms intervals. Therefore, after a switch is turned ON,
electrical loads are activated with a time delay. But this time delay is so short that it cannot be noticed.

Operation mode

●

Combination switch reading function has operation modes as follows:

Normal status

●

When BCM is not in sleep status, OUTPUT terminals (1-5) each turn ON-OFF every 10ms.

Sleep status

LIIA0760E

BCS-6

BCM (BODY CONTROL MODULE)

2007 Pathfinder

●

When BCM is in sleep mode, transistors of OUTPUT 1 and 5 stop the output, and BCM enters low-cur-
rent-consumption mode. OUTPUTS (2, 3, and 4) turn ON-OFF at 60ms intervals, and receives lighting
switch input only.

CAN COMMUNICATION CONTROL

CAN communication allows a high rate of information through the two communication lines (CAN-L, CAN-H)
connecting the various control units in the system. Each control unit transmits/receives data, but selectively
reads required data only.

BCM STATUS CONTROL

BCM changes its status depending on the operation status in order to save power consumption.

CAN communication status

●

With ignition switch ON, CAN communicates with other control units normally.

●

Control by BCM is being operated properly.

●

When ignition switch is OFF, switching to sleep mode is possible.

●

Even when ignition switch is OFF, if CAN communication with IPDM E/R and combination meter is
active, CAN communication status is active.

Sleep transient status

●

This status shuts down CAN communication when ignition switch is turned OFF.

●

It transmits sleep request signal to IPDM E/R and combination meter.

●

Two seconds after CAN communication of all control units stops, CAN communication switches to inac-
tive status.

CAN communication inactive status

●

With ignition switch OFF, CAN communication is not active.

●

With ignition switch OFF, control performed only by BCM is active.

●

Three seconds after CAN communication of all control units stops, CAN communication switches to
inactive status.

Sleep status

WKIA4093E

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