Hyundai Elantra (CN7): SRSCM / Occupant Classification System(OCS)

Hyundai Elantra (CN7) 2021-2025 Service Manual / Restraint / SRSCM / Occupant Classification System(OCS)

Description and operation

Description

1.	In order to make normal activation of airbag system, SRSCM detects DTC(s) for the Occupant Classification System (OCS). If the seat is occupied, OCS detects passenger presences status and send signal to SRSCM via CAN.

2.	SRSCM recognizes the signal as 2(two) different classifications; that is, 1(Empty or small occupant with child restraint system), 2(Occupied with large occupant and small occupant).

3.	With these signal, ACU determines whether it needs to deploy the PAB(Passenger Airbag) or not.

Components and components location

Components

1. Occupant Classification System (OCS) Unit

2. Occupant Classification System (OCS) Sensor

Occupant Classification Sensor Unit

Pin no	Name
1	ALR (-)
2	ALR (+)
3	Ground
4	CAN (Low)
5	CAN (High)
6	IGN1

Repair procedures

Removal

Occupant Classification System (OCS)

Disconnect the negative (-) battery terminal.

•	Disconnect the battery negative cable, and wait for at least three minutes before beginning work.

2.	Remove the passenger's side front seat assembly. (Refer to Body (Interior and Exterior) - "Front Seat Assembly")

3.	Remove the passenger seat cushion assembly. (Refer to Body (Interior and Exterior) - "Front Seat Cushion Cover")

4.	Disconnect occupant classification sensor unit connector (A).

5.	Remove the occupant classification sensor unit (A) after removing the clip.

Installation

Occupant Classification System (OCS)

1.	Install the occupant classification sensor unit in the passenger seat track assembly.

2.	Connect the occupant classification sensor unit connector.

3.	Install the passenger seat cushion assembly. (Refer to Body (Interior and Exterior) - "Front Seat Cushion Cover")

4.	Install the passenger's side front seat assembly. (Refer to Body (Interior and Exterior) - "Front Seat Assembly")

5.	Reconnect the battery negative (-) terminal.

After installing the OCS, confirm proper system operation.

•	Turn the ignition switch ON the SRS indicator should be turned on for about 6 seconds and then go off.

•	Telltale lamp will turn on for 4 seconds and be turned off for 3 seconds. After the 7 seconds, it shall remain off if the OCS does not require suppression and the passenger airbag is enabled.

•	Be sure to perform OCS reset with diagnostic tool after replacing OCS equipped seat cushion.

•	After initializing the OCS sensor unit, erase DTC regarding the SRSCM and the OCS sensor unit.

[DTC Manual]

DTC Code	Code Name	Description
B1697(87)	ACU Communication Error	1. ACU message cannot be received
B1603(88)	CAN BUS OFF	1. Vehicle CAN BUS bad reception
P1680(87)	VS Communication Fault	1. Vehicle speed message cannot be received
P1681(81)	VS Message Failure	1. Recive vehicle speed error signal
B1111(17)	Ignition Voltage High	1. High voltage condition (18.1V over)
B1112(16)	Ignition Voltage Low	1. Low voltage condition (6.7V under)
B1763(00)	OCS ECU Defect	ECU internal element failure or S/W failure
B1496(54)	OCS Not Calibrated	1. Sheet factory zero adjustment process missing
B1499(07)	ALR Defect	1. ALR broken

Inspection

OCS Reset procedure

You should perform OCS Reset procedure after service or replacement about all part of the passenger seat. (Not included full seat assembly)

1.	Ignition "OFF", connect GDS.

2.	Ignition "ON" & Engine "OFF", select S/W Management and "Car model".

3.	select OCS and "Body Sensor Reset".

4.	Perform the "Body sensor reset" procedure according to the GDS screen message.

❮Seat Belt Buckle Switch (BS)

Description and operation Description• The SRSCM should detect the condition of seat belt buckles (BS) of the driver and passenger seats.

Airbag Module❯

Other information:

Hyundai Elantra (CN7) 2021-2025 Service Manual: General safety information and caution

Instructions (R-134a)When Handling Refrigerant1.R-134a liquid refrigerant is highly volatile. A drop on the skin of your hand could result in localized frostbite. When handling the refrigerant, be sure to wear gloves. 2.It is standard practice to wear goggles or glasses to protect your eyes, and gloves to protect your hands.

Hyundai Elantra (CN7) 2021-2025 Service Manual: Heater Core

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