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Occupant Classification System (Diagnostic Codes & Symptom Tests): Overview Toyota Venza I

Restraints Control Systems 8 illustrations ~1329 words

DESCRIPTION

The passenger side buckle switch circuit consists of the occupant classification ECU and front seat inner belt assembly RH.

DTC B1771 is recorded when a malfunction is detected in the passenger side buckle switch circuit.

Troubleshoot DTC B1771 first if DTCs B1771 and B1795 are output simultaneously.

DTC No.DTC Detection ConditionTrouble Area
B1771The occupant classification ECU receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the passenger side buckle switch circuit for 2 seconds. Passenger side buckle switch malfunction Occupant classification ECU malfunctionFront seat inner belt assembly RH (Passenger side buckle switch) Occupant classification ECU Front seat wire RH (for Power seat) No. 2 Floor wire (for Manual seat)

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1771 is output, perform troubleshooting for the DTC.

Scheme 59

Scheme 59: WIRING DIAGRAM

The front occupant classification sensor LH circuit consists of the occupant classification ECU and front occupant classification sensor LH.

DTC B1780 is recorded when a malfunction is detected in the front occupant classification sensor LH circuit.

DTC No.DTC Detection ConditionTrouble Area
B1780The occupant classification ECU receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the front occupant classification sensor LH circuit for 2 seconds. Front occupant classification sensor LH malfunction Occupant classification ECU malfunctionFront seat assembly RH (Front occupant classification sensor LH) Occupant classification ECU Front seat wire RH

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1780 is output, perform troubleshooting for the DTC.

Scheme 60

Scheme 60: WIRING DIAGRAM

The front occupant classification sensor RH circuit consists of the occupant classification ECU and front occupant classification sensor RH.

DTC B1781 is recorded when a malfunction is detected in the front occupant classification sensor RH circuit.

DTC No.DTC Detection ConditionTrouble Area
B1781The occupant classification ECU receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the front occupant classification sensor RH circuit for 2 seconds. Front occupant classification sensor RH malfunction Occupant classification ECU malfunctionFront seat assembly RH (Front occupant classification sensor RH) Occupant classification ECU Front seat wire RH

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1781 is output, perform troubleshooting for the DTC.

Scheme 61

Scheme 61: WIRING DIAGRAM

The rear occupant classification sensor LH circuit consists of the occupant classification ECU and rear occupant classification sensor LH.

DTC B1782 is recorded when a malfunction is detected in the rear occupant classification sensor LH circuit.

DTC No.DTC Detection ConditionTrouble Area
B1782The occupant classification ECU receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the rear occupant classification sensor LH circuit for 2 seconds. Rear occupant classification sensor LH malfunction Occupant classification ECU malfunctionFront seat assembly RH (Rear occupant classification sensor LH) Front seat wire RH Occupant classification ECU

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1782 is output, perform troubleshooting for the DTC.

Scheme 62

Scheme 62: WIRING DIAGRAM

The rear occupant classification sensor RH circuit consists of the occupant classification ECU and rear occupant classification sensor RH.

DTC B1783 is recorded when a malfunction is detected in the rear occupant classification sensor RH circuit.

DTC No.DTC Detecting ConditionTrouble Area
B1783The occupant classification ECU receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the rear occupant classification sensor RH circuit for 2 seconds. Rear occupant classification sensor RH malfunction Occupant classification ECU malfunctionFront seat assembly RH (Rear occupant classification sensor RH) Occupant classification ECU Front seat wire RH

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1783 is output, perform troubleshooting for the DTC.

Scheme 63

Scheme 63: WIRING DIAGRAM

DTC B1785 is output when the occupant classification ECU receives a collision detection signal sent by the front occupant classification sensor LH if an accident occurs.

DTC B1785 is also output when the front seat assembly RH is subjected to a strong impact, even if an actual accident does not occur.

However, when the occupant classification ECU outputs a collision detection signal, even if the vehicle is not in a collision, DTC B1785 can be cleared by Zero Point Calibration and Sensitivity Check.

Therefore, if DTC B1785 is output, first perform Zero Point Calibration and Sensitivity Check.

DTC No.DTC Detection ConditionTrouble Area
B1785Front seat assembly RH malfunction Occupant classification ECU malfunction Front occupant classification sensor LH sensed large loadFront seat assembly RH (Front occupant classification sensor LH) Occupant classification ECU

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1785 is output, perform troubleshooting for the DTC.

DTC B1786 is output when the occupant classification ECU receives a collision detection signal sent by the front occupant classification sensor RH if an accident occurs.

DTC B1786 is also output when the front seat assembly RH is subjected to a strong impact, even if an actual accident does not occur.

However, when the occupant classification ECU outputs a collision detection signal, even if the vehicle is not in a collision, DTC B1786 can be cleared by Zero Point Calibration and Sensitivity Check.

Therefore, if DTC B1786 is output, first perform Zero Point Calibration and Sensitivity Check.

DTC No.DTC Detection ConditionTrouble Area
B1786Front seat assembly RH malfunction Occupant classification ECU malfunction Front occupant classification sensor RH sensed large loadFront seat assembly RH (Front occupant classification sensor RH) Occupant classification ECU

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1786 is output, perform troubleshooting for the DTC.

DTC B1787 is output when the occupant classification ECU receives a collision detection signal sent by the rear occupant classification sensor LH if an accident occurs.

DTC B1787 is also output when the front seat assembly RH is subjected to a strong impact, even if an actual accident does not occur.

However, when the occupant classification ECU outputs a collision detection signal, even if the vehicle is not in a collision, DTC B1787 can be cleared by Zero Point Calibration and Sensitivity Check.

Therefore, if DTC B1787 is output, first perform Zero Point Calibration and Sensitivity Check.

DTC No.DTC Detection ConditionTrouble Area
B1787Front seat assembly RH malfunction Occupant classification ECU malfunction Rear occupant classification sensor LH sensed large loadFront seat assembly RH (Rear occupant classification sensor LH) Occupant classification ECU

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1787 is output, perform troubleshooting for the DTC.

DTC B1788 is output when the occupant classification ECU receives a collision detection signal sent by the rear occupant classification sensor RH if an accident occurs.

DTC B1788 is also output when the front seat assembly RH is subjected to a strong impact, even if an actual accident does not occur.

However, when the occupant classification ECU outputs a collision detection signal, even if the vehicle is not in a collision, DTC B1788 can be cleared by Zero Point Calibration and Sensitivity Check.

Therefore, if DTC B1788 is output, first perform Zero Point Calibration and Sensitivity Check.

DTC No.DTC Detection ConditionTrouble Area
B1788Front seat assembly RH malfunction Occupant classification ECU malfunction Rear occupant classification sensor RH sensed large loadFront seat assembly RH (Rear occupant classification sensor RH) Occupant classification ECU

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1788 is output, perform troubleshooting for the DTC.

The center airbag sensor assembly communication circuit consists of the occupant classification ECU and center airbag sensor assembly.

DTC B1790 is recorded when a malfunction is detected in the center airbag sensor assembly communication circuit.

DTC No.DTC Detecting ConditionTrouble Area
B1790The occupant classification ECU receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the center airbag sensor assembly communication circuit. Occupant classification ECU malfunction Center airbag sensor assembly malfunctionOccupant classification ECU Center airbag sensor assembly Front seat wire RH (for Power seat) Floor wire No. 2 Junction connector

Scheme 64

Scheme 64: WIRING DIAGRAM

The occupant classification sensor power supply circuit consists of the occupant classification ECU and occupant classification sensors.

DTC B1793 is recorded when a malfunction is detected in the occupant classification sensor power supply circuit.

DTC No.DTC Detection ConditionTrouble Area
B1793The occupant classification ECU receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the occupant classification sensor power supply circuit for 2 seconds. Occupant classification ECU malfunctionFront seat assembly RH (Occupant classification sensors) Occupant classification ECU Front seat wire RH

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1793 is output, perform troubleshooting for the DTC.

Scheme 65

Scheme 65: WIRING DIAGRAM

This circuit consists of the occupant classification ECU and power source circuit (battery, fuse and wire harness).

DTC B1794 is recorded when a malfunction is detected in the occupant classification ECU or power source circuit.

HINT

If DTC B1794 is output after turning the ignition switch from off to ON and to off 50 times in a row when a malfunction occurs in the power circuit for the occupant classification system.

This DTC is output if a malfunction is detected even after being cleared unless the normal system code is input.

DTC No.DTC Detection ConditionTrouble Area
B1794The ignition switch is turned from off to ON, hold for 10 seconds or more, and turned off again 50 times in a row when a malfunction occurs in the power circuit for the occupant classification system. Occupant classification ECU malfunctionBattery ECU-B fuse Wire harness Occupant classification ECU

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1794 is output, perform troubleshooting for the DTC.

Scheme 66

Scheme 66: WIRING DIAGRAM

DTC B1795 is recorded when a malfunction is detected in the occupant classification ECU.

Troubleshoot DTC B1771 first if DTCs B1771 and B1795 are output simultaneously.

DTC No.DTC Detection ConditionTrouble Area
B1795Front seat inner belt assembly RH malfunction Occupant classification ECU malfunctionFront seat inner belt assembly RH Occupant classification ECU

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1795 is output, perform troubleshooting for the DTC.

In sleep mode, the occupant classification ECU reads the condition of each sensor while the ignition switch is off.

In this mode, if occupant classification ECU detects an internal malfunction, DTC B1796 is output.

DTC No.DTC Detection ConditionTrouble Area
B1796Occupant classification ECU malfunctionOccupant classification ECU

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1796 is output, perform troubleshooting for the DTC.

The occupant classification system detects the front passenger seat condition. It then informs a passenger of the front passenger airbag assembly and front seat side airbag assembly RH condition (activated/not activated) with the passenger airbag ON/OFF indicator.

HINT

Approximately 6 seconds after the ignition switch is turned to ON, the passenger airbag ON/OFF indicator will be ON/OFF depending on the conditions listed below.

Front Passenger Seat ConditionPassenger Airbag ON/OFF IndicatorSRS Warning Light
ON IndicatorOFF Indicator
VacantOFFOFFOFF
Adult is seated.ONOFFOFF
Child is seated.OFFONOFF
Child restraint system is set.OFFONOFF
Occupant classification system failureOFFONON