Infiniti G35 (V35) Sedan. Manual - part 1220

SRC-28

< COMPONENT DIAGNOSIS >

B1017, B1020, B1021 OCCUPANT SENS C/U

B1017, B1020, B1021 OCCUPANT SENS C/U

Description

INFOID:0000000000959606

DTC B1017, B1020, B1021 [UNIT FAIL] OCCUPANT SENS C/U

Suppresses the deployment of passenger air bag when the condition of passenger seat is empty, child and
child-seat. And turn on cut-off telltale lamp when the condition of passenger seat is child-seat and child. In
case of malfunction the blinking of the SRS air bag warning lamp tells the trouble to driver and by the on board
self-diagnosis system or electro diagnosis tester CONSULT-lll can detects the cause.

OPERATION

This unit classifies occupant on a passenger seat and detects electrical trouble in Occupant Classification
System, and transmits trouble information to air bag control unit.

STRUCTURE

It is integrated into the seat sensor mat and detects the occupants with Occupant Classification System (OCS)
control unit that classifies the occupants.

INSTALLATION

 Occupant Classification System (OCS) control unit is installed in the passenger seat cushion.

DTC Logic

INFOID:0000000000959607

DTC DETECTION LOGIC

With CONSULT-lll

DTC No. Index (“SELF-DIAG [CURRENT]”), (“SELF-DIAG [PAST]” or “TROUBLE DIAG RECORD”)

Without CONSULT-lll

Warning Lamp Flash Code Chart

DTC CONFIRMATION PROCEDURE (With CONSULT-lll)

1.

IGNITION SWITCH

Turn ignition switch ON.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

B1017
B1020
B1021

OCCUPANT SENS C/U 
[UNIT FAIL]

Trouble occurs in OCS-C/U.

1.

Visually check the wiring harness 
connection.

2.

Replace the harness if it has visi-
ble damage.

3.

Replace front passenger seat 
cushion and occupant classifica-
tion system control unit as an as-
sembly.

4.

Replace diagnosis sensor unit 
(ACU).

JMHIA0045GB

B1017, B1020, B1021 OCCUPANT SENS C/U

SRC-29

< COMPONENT DIAGNOSIS >

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>> GO TO 2.

2.

CONSULT-LLL

Select “DIAG MODE” with CONSULT-lll.

>> GO TO 3.

3.

DTC CODE

If DTC is detected. Refer to 

SRC-30

>> END

DTC CONFIRMATION PROCEDURE (Without CONSULT-lll)

NOTE:
• SRS will not enter diagnosis mode if no malfunction is detected in user mode.

1.

IGNITION SWITCH

Turn ignition switch ON.

>> GO TO 2.

2.

USER MODE-DIAG MODE

After air bag warning lamp illuminates for 7 seconds, turn ignition switch OFF within 1 second.

>> GO TO 3.

3.

USER MODE-DIAG MODE

Wait more than 3 seconds.

>> GO TO 4.

4.

USER MODE-DIAG MODE

Repeat step 1 to 3 twice. (Perform three times in all.)

>> GO TO 5.

5.

DIAG MODE

Turn ignition switch ON. (SRS is now in diagnosis mode.)

>> GO TO 6.

6.

DIAG MODE (AIR BAG WARNING LAMP)

Malfunctioning portion is indicated according to blinking times of air bag warning lamp. Refer to 

SRC-30

SRC-30

< COMPONENT DIAGNOSIS >

B1017, B1020, B1021 OCCUPANT SENS C/U

>> END

Diagnosis Procedure (Component diagnosis)

INFOID:0000000000959608

With CONSULTlll

CAUTION:

• Before servicing, turn ignition switch OFF, disconnect both battery terminals and wait at least 3 min-

utes. (To discharge backup capacitor.)

• Do not use unspecified tester or other measuring device. 

DIAGNOSTIC PROCEDURE

1.

CHECK HARNESS CONNECTOR

Check the harness connector.

Are connections of harness connectors and terminals correct?

YES

>> GO TO 2.

NO

>> Repair or replace harness connectors.

2.

CHECK WIRING HARNESS

Check the wiring harness.
Is the outside of wiring harness normal, without any damage?

YES

>> GO TO 3.

NO

>> Replace wiring harness.

3.

CHECK OCCUPANT SENSOR C/U

Check the displayed on CONSULT-lll?
Is “OCCUPANT SENSOR C/U” displayed on CONSULT-lll?

YES

>> Replace passenger side seat cushion assembly.
>> INSPECTION END.

B1018 OCCUPANT SENS

SRC-31

< COMPONENT DIAGNOSIS >

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B1018 OCCUPANT SENS

Description

INFOID:0000000000959609

DTC B1018 [UNIT FAIL] OCCUPANT SENS

Suppresses the deployment of passenger air bag when the condition of passenger seat is empty, child and
child-seat. And turn on cut-off telltale lamp when the condition of passenger seat is child-seat and child. In
case of malfunction the blinking of the SRS air bag warning lamp tells the trouble to driver and by the on board
self-diagnosis system or electro diagnosis tester CONSULT-lll can detects the cause.

OPERATION

The unit classifies occupant on a passenger seat and transmits it to Occupant Classification System (OCS)
control unit.

STRUCTURE

Plural sensors are installed in the sensor mat to prevent wrong sensing induced by the sitting position.

INSTALLATION

Seat sensor mat is installed in the passenger seat cushion.

DTC Logic

INFOID:0000000000959610

DTC DETECTION LOGIC

With CONSULT-lll

DTC No. Index (“SELF-DIAG [CURRENT]”), (“SELF-DIAG [PAST]” or “TROUBLE DIAG RECORD”)

Without CONSULT-lll

Warning Lamp Flash Code Chart

DTC CONFIRMATION PROCEDURE (With CONSULT-lll)

1.

IGNITION SWITCH

Turn ignition switch ON.

>> GO TO 2.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

B1018

OCCUPANT SENS 
[UNIT FAIL]

Trouble occurs in OCS – SENS.

1.

Visually check the wiring harness 
connection.

2.

Replace the harness if it has visi-
ble damage.

3.

Replace front passenger seat 
cushion and occupant classifica-
tion system control unit as an as-
sembly.

4.

Replace diagnosis sensor unit 
(ACU).

JMHIA0045GB