Seat Belt Warning System (Diagnostics): Overview Lexus GS III рестайлинг

SYSTEM DESCRIPTION

1. SEAT BELT WARNING SYSTEM DESCRIPTION If a seat belt is not fastened, this system flashes the seat belt warning light or sounds the seat belt warning buzzer as a reminder.
2. FUNCTION OF MAIN COMPONENT The following functions are available: Components Function Front seat inner belt LH (for driver side) Informs center airbag sensor of driver seat belt condition (fastened or unfastened) Front seat inner belt RH (for passenger side) Informs center airbag sensor of front passenger seat belt condition (fastened or unfastened) Occupant classification sensor Informs center airbag sensor of front passenger seat condition (occupied or unoccupied) Driver seat belt warning Light If driver seat belt is unfastened and power switch is ON (IG), combination meter flashes seat belt warning light of instrument cluster finish panel as reminder Passenger airbag ON/OFF indicator (front passenger seat belt warning light) When front passenger seat is occupied and power switch is ON (IG), if passenger seat belt is unfastened, combination meter flashes seat belt warning light of multi-display as reminder Seat belt warning buzzer If driver or passenger seat belt is unfastened and power switch is ON (IG), combination meter sounds buzzer as reminder
3. SYSTEM OPERATION Driver seat belt warning light When the driver seat belt is not fastened with the power switch ON (IG), the driver seat belt warning light on the combination meter comes on to inform the driver. The center airbag sensor detects the driver seat belt status and sends signals to the combination meter a using BEAN. Passenger airbag ON/OFF indicator (front passenger seat belt warning light) When the passenger seat belt is not fastened with the power switch ON (IG) and the passenger seat occupied, check that the passenger airbag ON/OFF indicator (front passenger seat belt warning light) on the multi-display blinks. The multi-display displays the passenger seat belt status and whether the passenger seat is occupied.

DESCRIPTION

1. When the power switch is ON (IG), the center airbag sensor communicates the status of the front seat inner belt LH (for driver side) to the combination meter using the BEAN line. When the seat belt is unfastened, the combination meter flashes the driver side seat belt warning light on the combination meter. When the seat belt is fastened, the combination meter stops flashing the warning light.

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1. CHECK SUPPLEMENTAL RESTRAINT SYSTEM Check for supplemental restraint system (SRS) DTCs. RESULT Result Proceed to No SRS DTCs are output A SRS DTCs are output B B --> See step 4 A: Go to next step
2. PERFORM ACTIVE TEST USING TECHSTREAM (SEAT BELT WARNING LIGHT FOR DRIVER SIDE) Select the ACTIVE TEST, use Techstream to generate a control command, and then check that the seat belt warning light operates. COMBINATION METER Tester Display Test Part Control Range Diagnostic Note Driver Side Seat Belt Driver side seat belt warning light OFF/ ON Confirm that vehicle is stopped and engine is idling OK Seat belt warning light for driver side operates normally. OK --> REPLACE CENTER AIRBAG SENSOR NG: Go to next step
3. INSPECT INSTRUMENT CLUSTER FINISH PANEL (SEAT BELT WARNING LIGHT FOR DRIVER SIDE) Remove the panel. Apply battery voltage and check that the seat belt warning light illuminates. OK Measurement Condition Specified Condition Battery positive (+) --> Terminal 11 Battery negative (-) --> Terminal 6 Seat belt warning light illuminates HINT: When the battery's negative (-) lead is applied to terminal 11 and the positive (+) lead is applied to terminal 6, the seat belt warning light does not illuminate. NG --> REPLACE INSTRUMENT CLUSTER FINISH PANEL OK --> REPLACE COMBINATION METER
4. GO TO SUPPLEMENTAL RESTRAINT SYSTEM. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-387113-S15923942092011022400000)

The combination meter detects the state of the front seat inner belt RH when the front passenger seat is occupied with the power switch ON (IG). If the front passenger seat belt is not fastened, the front passenger seat belt warning light on the multi-display blinks. If the seat belt is fastened, the warning light goes off.

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1. CHECK FOR DTC Check for DTCs. RESULT: Result Proceed to DTC does not occur A Multiplex communication system DTC output occurs B Airbag system DTC output occurs C Occupant classification system DTC output occurs D D --> See step 9 C --> See step 8 B --> See step 7 A: Go to next step
2. INSPECT FUSE (ECU-IG RH) Remove the ECU-IG RH fuse from the driver side junction block. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition ECU-IG RH fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
3. PERFORM ACTIVE TEST USING TECHSTREAM Operate Techstream according to the steps on the display and select "ACTIVE TEST". METER ECU: Tester Display Test Part Control Range Diagnostic Note Front Passenger Side Seat belt* Passenger seat belt warning light ON or OFF - HINT: *: Confirm that the vehicle is stopped with the power switch ON (READY). OK Passenger seat belt warning light condition can be switched by "ACTIVE TEST". NG --> See step 10 OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (MULTI-DISPLAY - COMBINATION METER, BATTERY AND BODY GROUND) Disconnect the K46 display connector. Measure the resistance and voltage according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition K46-21 (PBEW) - K31-31 (PBLT) Always Below 1 ohms K46-10 (GND1) - Body ground K46-21 (PBEW) or K31-31 (PBLT) - Body ground 10 kohms or higher Standard voltage Tester Connection Switch Condition Specified Condition K46-3 (IG) - Body ground Power switch ON (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. CHECK MULTI-DISPLAY Disconnect the K46 display connector. Connect the battery's positive (+) lead to terminal 3 (IG), and the negative (-) lead to terminals 21 (PBEW) and 10 (GND1). Check that the seat belt warning light comes on. OK Seat belt warning light comes on. NG --> See step 11 OK: Go to next step
6. INSPECT FRONT SEAT INNER BELT ASSEMBLY RH Disconnect the a18 belt connector. Connect the battery's positive (+) lead to terminal 1 of the front seat inner belt RH connector. Connect the battery's negative (-) lead to the negative (-) terminal of a tester. Connect the positive (+) terminal of the tester to terminal 2 of the front seat inner belt RH connector. Measure the current according to the value(s) in the table below. Standard current Tester Connection Switch Condition Specified Condition 1 - 2 Tongue plate inserted 12 to 18 mA Tongue plate not inserted 4 to 7 mA NG --> See step 12 OK --> See step 13
7. Go to MULTIPLEX COMMUNICATION SYSTEM. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-386979-S33914524662011022400000)
8. Go to AIRBAG SYSTEM. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-387113-S15923942092011022400000)
9. Go to OCCUPANT CLASSIFICATION SYSTEM. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-386978-S17110740792011022400000)
10. REPLACE COMBINATION METER ASSEMBLY. Refer to «REMOVAL»(/lexus/gs/iii-2007-2011/remont/gauges-instrument-panels/#combination-meter-service-information)
11. REPLACE MULTI-DISPLAY. Refer to «REMOVAL»(ref-387134-S21927137462011022400000)
12. REPLACE FRONT SEAT INNER BELT ASSEMBLY RH. Refer to «REMOVAL»(ref-387151-S20580642782011022400000)
13. REPLACE OCCUPANT CLASSIFICATION ECU. Refer to «DISASSEMBLY»(ref-386977-S02613025932011022400000)

See also:
• REMOVAL