Hyundai Elantra CN7: SRSCM

Seventh generation (CN7; 2021–2025) / Hyundai Elantra CN7 2021-2025 Workshop Manual / Restraint / SRSCM

Components and components location

Components

1. Front impact sensor (FIS)
2. Supplemental Restraint System Control Module (SRSCM)
3. Front impact sensor (FIS)

4. Gravity side Impact Sensor (G-SIS)
5. Pressure Side Impact Sensor (P-SIS)

SRS Control Module (SRSCM)

Description and operation

Description

•	Supplemental Restraint System Control Module (SRSCM) determines whether and when to deploy air bag module, seat belt pretensioner (BPT).

•	It supplies the air bag module with the power required to deploy the module or the BPT.

•	It also performs self-diagnosis function of the supplemental restraint system.

Components and components location

Components

1. Supplemental Restraint System Control Module (SRSCM)

Supplemental Restraint System Control Module (SRSCM)

No	Connector A	Connector B
1	IGN 1	Ground
2	Driver front impact sensor - High (+)	Driver seat belt pretensioner - High (+)
3	Driver front impact sensor - Low (-)	Driver seat belt pretensioner - Low (-)
4	Driver airbag 1st stage - High (+)	Driver adapted road limiter - High (+)
5	Driver airbag 1st stage - Low (-)	Driver adapted road limiter - Low (-)
6	Passenger airbag 1st stage - Low (-)	Driver side airbag - High (+)
7	Passenger airbag 1st stage - High (+)	Driver side airbag - Low (-)
8	-	Passenger side airbag - Low (-)
9	-	Passenger side airbag - High (+)
10	Crash signal output	Driver side impact sensor - High (+)
11	Passenger front impact sensor - High (+)	Driver side impact sensor - Low (-)
12	Passenger front impact sensor - Low (-)	Passenger side impact sensor - Low (-)
13	Driver airbag 2nd stage - High (+)	Passenger side impact sensor - High (+)
14	Driver airbag 2nd stage - Low (-)	Passenger seat belt buckle sensor - High (+)
15	Passenger airbag 2nd stage - Low (-)	Passenger seat belt pretensioner - High (+)
16	Passenger airbag 2nd stage - High (+)	Passenger seat belt pretensioner - Low (-)
17	C-CAN (High)	-
18	C-CAN (Low)	-
19	B +	Driver curtain airbag - High (+)
20	Passenger airbag OFF lamp	Driver curtain airbag - Low (-)
21	-	Passenger curtain airbag - Low (-)
22	-	Passenger curtain airbag - High (+)
23	-	Driver Passenger side impact sensor - High (+)
24	-	Driver pressure side impact sensor - Low (-)
25	-	Passenger pressure side impact sensor - Low (-)
26	Local CAN (High)	Passenger Passenger side impact sensor - High (+)
27	Local CAN (Low)	Driver seat belt buckle sensor - High (+)
28		Driver rear seat belt pretensioner - High (+)
29		Driver rear seat belt pretensioner - Low (-)
30		Passenger rear seat belt pretensioner - High (+)
31		Passenger rear seat belt pretensioner - Low (-)
32		-
33		-
34		-
35		-
36		-
37		-
38		-
39		-

Repair procedures

Removal

Turn the ignition switch OFF and disconnect the battery negative (-) cable.

•	Disconnect the battery negative cable from the battery and then wait for at least 3 minutes.

2.	Remove the floor console assembly. (Refer to Body - "Floor Console Assembly")

3.	Remove the center console duct (A).

Pull up the lock of the SRSCM connector to disconnect the connector (A).

•	Be careful SRSCM connector damage.

5.	Remove the SRSCM (A) after loosening the mounting nuts.

Installation

Check if the battery (-) cable is disconnected.

•	Disconnect the battery negative cable from the battery and then wait for at least 3 minutes.

Install the SRSCM (A) with the SRSCM mounting nuts.

Tightening torque :

7.8 - 9.8 N.m (0.8 - 1.0 kgf.m, 5.8 - 7.2 lb-ft)

3.	Connect the SRSCM harness connector.

4.	Install the heater ducts and floor console. (Refer to Body - "Floor Console Assembly")

5.	Reconnect the battery negative cable.

After installing the SRSCM, confirm proper system operation :

•	Turn the ignition switch ON; the SRS indicator light should be turned on for about six seconds and then turns off.

Adjustment

[Variant Coding]

1.	Connect the cable of diagnostic tool to the data link connector in driver side crash pad lower panel, and turn on the diagnostic tool.

2.	Select the 'S/W Management' and 'Car model'.

3.	Select "Airbag" and "ACU/SRSCM Variant Coding".

4.	Perform the "ACU/SRSCM Variant Coding" procedure according to the GDS screen message.

[Longitudinal G Sensor Calibration]

1.	Connect the cable of diagnostic tool to the data link connector in driver side crash pad lower panel, and turn on the diagnostic tool.

2.	Select the 'S/W Management' and 'Car model'.

Select "Longitudinal G Sensor Calibration".

•	You must remove or install the SRSCM or other SRS components with the ignition switch OFF to avoid accidental airbag deployment.

Front Impact Sensor (FIS)

Description and operation

Description

The front impact sensor (FIS) is installed in the Front End Module (FEM). They are remote sensors that detect acceleration due to a collision at its mounting location.

The primary purpose of the Front Impact Sensor (FIS) is to provide an indication of a collision. The Front Impact Sensor (FIS) sends acceleration data to the SRSCM.

Components and components location

Components

1. Passenger front impact sensor (FIS)

2. Driver front impact sensor (FIS)

Repair procedures

Removal

Disconnect the negative (-) battery terminal.

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

2.	Disconnect the front impact sensor connector (B) and then remove the front impact sensor (A) after loosening the mounting bolt. [LH] [RH]

Installation

Check if the battery (-) cable is disconnected.

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

2.	Install a new front impact sensor and connect the front impact sensor connector.

Tighten the front impact sensor mounting bolt.

Tightening torque :

7.8 - 10.8 N.m (0.8 - 1.0 kgf.m, 6.5 - 5.8 lb-ft)

•	If tightening by excessive force beyond the specified tightening torque, the forward collision detecting sensor may be damaged. Therefore, make sure to do work in accordance with the specified tightening torque.

4.	Reconnect the battery negative (-) terminal.

After installing the front impact sensor, confirm proper system operation.

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

Side Impact Sensor (SIS)

Description and operation

Description

•	Side Impact Sensors (SIS), each installed on the center part of the right and left front door modules and the right and left center pillars, detects side impact during collision.

•	The pressure-sensitive side collision detection sensor (P-SIS) is a method that senses the pressure when it collides, and is also called P-SIS, and the side collision detection sensor (G-SIS) is a method that senses the acceleration at the time of collision. Also called G-SIS.

•	The SRSCM uses the signals from SIS during side collision to determine whether and when to deploy the side air bag.

Components and components location

Components

1. Pressure Side Impact Sensor (P-SIS)

2. Gravity Side Impact Sensor (G-SIS)

Repair procedures

Removal

Pressure Side Impact Sensor (P-SIS)

Disconnect the negative (-) battery terminal.

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

2.	Remove the front door trim. (Refer to Body - "Front Door Trim")

3.	Disconnect the pressure side impact sensor connector (A) after pushing the lock pin.

4.	Remove the pressure side impact sensor (A) after rotating it in the direction of the arrow.

Gravity Side Impact Sensor (G-SIS)

Disconnect the negative (-) battery terminal.

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

2.	Remove the center pillar trim. (Refer to Body (Interior and Exterior) - "Center Pillar Trim")

3.	Remove the gravity side impact sensor (A) after loosening the mounting bolt and disconnecting the connector (B).

Installation

Pressure Side Impact Sensor (P-SIS)

Check if the battery (-) cable is disconnected.

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

2.	Install a new pressure side impact sensor and connect the pressure side impact sensor connector.

3.	Install the front door trim. (Refer to Body - "Front Door Trim")

4.	Reconnect the battery negative (-) terminal.

After installing the front impact sensor, confirm proper system operation.

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

•	Problems may be occurred in the durability of P-SIS or impact sensing performance may be depreciated if POP-NUT is rotated.

•	The door module must not be transformed because SRSCM judges a impact through the pressure sensor in the door module.

Gravity Side Impact Sensor (G-SIS)

Check if the battery (-) cable is disconnected.

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

Install the new side impact sensor with the screws, then connect the front side impact sensor connector.

Tightening torque :

7.8 - 10.8 N.m (0.8 - 1.0 kgf.m, 6.5 - 5.8 lb-ft)

3.	Install the center pillar trim. (Refer to Body (Interior and Exterior) - "Center Pillar Trim")

Reconnect the battery negative (-) terminal.

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

•	You must comply with the specified tightening torques with the tool specified because Gravity – Side Impact Sensors (G-SIS) may be broken or POP-NUT may be rotated.

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.

•	The SRSCM provides two pins to each side, in order to enter the condition of seat belt buckles (BS) of the driver and passenger seats.

•	The seat belt buckle circuit is operated using internal boost voltage supplied by the SRSCM, and uses body ground for signal return.

Components and components location

Components

1. Seat belt buckle switch (BS)

Repair procedures

Removal

Disconnect the negative (-) battery terminal.

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

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

3.	Disconnect the front seat belt buckle connector wiring (A).

Remove the front seat belt buckle (A) after loosening the monuting bolt.

Tightening torque :

39.2 - 53.9 N.m (4.0 - 5.5 kgf.m, 28.9 - 39.8 lb-ft)

To install, reverse the removal procedures.

•	Replace damaged clip.

•	Assemble the connector securely.

•	When the ignition switch is turned on after installing the airbag, check that the warning light turns on for about 6 seconds and then goes out.

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.

Repair procedures

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