Nissan Sentra B18 (2020-2025) Service Manual: System
Srs Air Bag Control System
System Description
System Description
SYSTEM DIAGRAM
System Description
-
The air bag deploys if the air bag diagnosis sensor unit is activated while the ignition switch is in the ON or START position.
-
The collision modes for which supplemental restraint systems are activated are different among the SRS systems. For example, the driver air bag module, front passenger air bag module and front seat belt pre-tensioners are activated in a frontal collision but not in a side collision.
SRS Collision Modes
|
SRS configuration |
Frontal collision |
Left side collision |
Right side collision |
Rollover |
|---|---|---|---|---|
|
Driver air bag module |
x |
— |
— |
— |
|
Front passenger air bag module |
x |
— |
— |
— |
|
Left knee air bag module |
x |
— |
— |
— |
|
Right knee air bag module |
x |
— |
— |
— |
|
Front LH seat belt pre-tensioner |
x |
— |
— |
x |
|
Front RH seat belt pre-tensioner |
x |
— |
— |
x |
|
Rear LH seat belt pre-tensioner |
x |
— |
— |
x |
|
Rear RH seat belt pre-tensioner |
x |
— |
— |
x |
|
Front LH side air bag module |
— |
x |
— |
— |
|
Front RH side air bag module |
— |
— |
x |
— |
|
Rear LH side air bag module |
— |
x |
— |
x |
|
Rear RH side air bag module |
— |
— |
x |
x |
|
LH side curtain air bag module |
— |
x |
— |
x |
|
RH side curtain air bag module |
— |
— |
x |
x |
Occupant Classification System
System Description
System Description
SYSTEM DIAGRAM
System Description
The occupant classification system (OCS) identifies different size occupants, out of position occupants, and detects if a child seat is present in the front passenger seat. The OCS control unit (2) receives inputs from the occupant classification system sensors (1) (located inside the passenger seat cushion assembly). Depending on classification of the passenger, the OCS sends a signal to the air bag diagnosis sensor unit. The air bag diagnosis sensor unit uses this signal and the front seat belt buckle switch RH signal to determine deployment or non deployment of the front passenger air bag module in the event of a collision. Depending on the signals received, the air bag diagnosis sensor unit can disable the front passenger air bag module completely. The OCS (weight sensors) must be set to zero point using CONSULT after servicing the OCS system.
Note:
-
CONSULT can be used to confirm when “zero point reset” for OCS is complete.
-
Always perform zero point reset after the removal and installation of the seat or when disconnecting the OCS control unit harness connector even if zero point reset has been completed in the past.
-
If zero point reset is incomplete, the passenger air bag will be disabled and the passenger air bag off indicator will be ON.
-
In case of customer concern, CONSULT can be used to confirm the passenger air bag status (readiness).
|
Front Passenger Seat (Condition) |
PASS AIR BAG OFF Indicator (Status) |
Passenger Air Bag Status (Readiness) |
CONSULT Display |
|---|---|---|---|
|
Seat occupied |
OFF |
Active (enabled) |
ON |
|
Seat occupied NOTE |
ON |
Deactivated (disabled) |
OFF |
|
Seat empty |
OFF |
Deactivated (disabled) |
OFF |
Passenger does not meet Occupant Classification System specifications for passenger air bag activation.
Seat Belt Warning Lamp System
System Description
System Description
SYSTEM DIAGRAM
System Description
The seat belt warning lamp (1) will remind the driver if the driver or front passenger seat belt should be buckled. The system works in conjunction with the occupant classification system. Refer to System Description.
|
Driver seat status (Ignition switch ON) |
Passenger seat status |
Front seat belt buckle switch LH status |
Front seat belt buckle switch RH status |
Seat belt warning lamp |
|---|---|---|---|---|
|
Seat occupied |
Seat occupied |
Buckled |
Buckled |
Off |
|
Unbuckled |
On |
|||
|
Seat unoccupied |
— |
Off |
||
|
— |
Unbuckled |
On |
Other materials:
Diagnosis System (a/c Auto Amp.)
Description
Description
Air conditioning system performs self-diagnosis,
operation check, function diagnosis, and various settings using diagnosis
function of each control unit.
ECU
Diagnostic i ...
Power Supply, Ground & Circuit Elements. Preparation. Preparation
Preparation
Special Service Tool
Special Service Tool
Tool number
(TechMate No.)
Tool name
Description
165-GR8-1200KIT ...
Chime Does Not Sound
Diagnosis Procedure
Diagnosis Procedure
The warning chime may not sound in some cases when there is a
short distance between vehicles. Some examples are:
When the Nissan Sentra vehicles are traveling at the same speed and the
distance between vehicles is not changing.
...