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Occupant Classification System (Diagnostic Codes & Symptom Tests): Overview Toyota Corolla XI

Airbag 8 illustrations ~669 words

DESCRIPTION

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

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

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1782Rear Occupant Classification Sensor LH Circuit MalfunctionThe occupant detection ECU detects a line short, short to ground or B+, or an open in the rear occupant classification sensor LH circuit. Rear occupant classification sensor LH malfunction Occupant detection ECU malfunctionFor TMMMS Made: Front seat wire RH Rear occupant classification sensor LH (Separate type front seat cushion spring assembly RH)* Occupant detection ECU for TMMC Made: Front seat inner belt assembly RH Front seat wire RH Rear occupant classification sensor LH (Front seat adjuster sub-assembly RH)* Occupant detection ECU
  1. *: The rear occupant classification sensor LH is built into the separate type front seat cushion spring assembly RH or front seat adjuster sub-assembly RH.

Scheme 204

Scheme 204: WIRING DIAGRAM
Scheme 204: WIRING DIAGRAM

Scheme 205

Scheme 205
Scheme 205
  1. for TMMMS Made
  2. for TMMC Made

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

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

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1783Rear Occupant Classification Sensor RH Circuit MalfunctionThe occupant detection ECU detects a line short, short to ground or B+, or an open in the rear occupant classification sensor RH circuit. Rear occupant classification sensor RH malfunction Occupant detection ECU malfunctionFor TMMMS Made: Front seat wire RH Rear occupant classification sensor RH (Separate type front seat cushion spring assembly RH)* Occupant detection ECU for TMMC Made: Front seat wire RH Rear occupant classification sensor RH (Front seat adjuster sub-assembly RH)* Occupant detection ECU
  1. *: The rear occupant classification sensor RH is built into the separate type front seat cushion spring assembly RH or front seat adjuster sub-assembly RH.

Scheme 206

Scheme 206: WIRING DIAGRAM
Scheme 206: WIRING DIAGRAM

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

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

If the vehicle was not in a collision, but the occupant detection ECU receives a collision detection signal and stores DTC B1787, the DTC can be cleared by performing Zero Point Calibration and Sensitivity Check.

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

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1787Rear Occupant Classification Sensor LH Collision DetectionFor TMMMS Made: Rear occupant classification sensor LH sensed large load Separate type front seat cushion spring assembly RH malfunction for TMMC Made: Rear occupant classification sensor LH sensed large load Front seat adjuster sub-assembly RH malfunctionFor TMMMS Made: Rear occupant classification sensor LH (Separate type front seat cushion spring assembly RH)* for TMMC Made: Rear occupant classification sensor LH (Front seat adjuster sub-assembly RH)*
  1. *: The rear occupant classification sensor LH is built into the separate type front seat cushion spring assembly RH or front seat adjuster sub-assembly RH.

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

In this mode, if the occupant detection ECU detects an internal malfunction, DTC B1796 is stored.

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1796Sleep Operation Failure of Occupant Classification ECUOccupant detection ECU malfunctionOccupant detection ECU

DTC B1795 is stored when a malfunction is detected in the occupant detection ECU.

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1795Occupant Classification ECU MalfunctionOccupant detection ECU malfunctionOccupant detection ECU

DTC B1794 is stored when a malfunction is detected in the occupant detection ECU battery positive line.

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1794Open in Occupant Classification ECU Battery Positive LineThe occupant detection ECU detects an open in the occupant detection ECU battery positive line. Occupant detection ECU malfunctionBattery Wire harness Occupant detection ECU

Scheme 207

Scheme 207: WIRING DIAGRAM
Scheme 207: WIRING DIAGRAM

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

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

If the vehicle was not in a collision, but the occupant detection ECU receives a collision detection signal and stores DTC B1788, the DTC can be cleared by performing Zero Point Calibration and Sensitivity Check.

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

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1788Rear Occupant Classification Sensor RH Collision DetectionFor TMMMS Made: Rear occupant classification sensor RH sensed large load Separate type front seat cushion spring assembly RH malfunction for TMMC Made: Rear occupant classification sensor RH sensed large load Front seat adjuster sub-assembly RH malfunctionFor TMMMS Made: Rear occupant classification sensor RH (Separate type front seat cushion spring assembly RH)* for TMMC Made: Rear occupant classification sensor RH (Front seat adjuster sub-assembly RH)*
  1. *: The rear occupant classification sensor RH is built into the separate type front seat cushion spring assembly RH or front seat adjuster sub-assembly RH.

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

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

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1790Center Airbag Sensor Assembly Communication Circuit MalfunctionThe occupant detection ECU detects a line short, short to ground or B+, or an open in the center airbag sensor assembly communication circuit. Occupant detection ECU malfunction Airbag sensor assembly malfunctionFloor wire Front seat wire RH Occupant detection ECU Airbag sensor assembly

Scheme 208

Scheme 208: WIRING DIAGRAM
Scheme 208: WIRING DIAGRAM

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

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

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1793Occupant Classification Sensor Power Supply Circuit MalfunctionThe occupant detection ECU detects a line short, short to ground or B+ in the occupant classification sensor power supply circuit. Rear occupant classification sensor LH malfunction Rear occupant classification sensor RH malfunction Occupant detection ECU malfunctionFor TMMMS Made: Front seat wire RH Rear occupant classification sensor LH (Separate type front seat cushion spring assembly RH)* Rear occupant classification sensor RH (Separate type front seat cushion spring assembly RH)* Occupant detection ECU for TMMC Made: Front seat inner belt assembly RH Front seat wire RH Rear occupant classification sensor LH (Front seat adjuster sub-assembly RH)* Rear occupant classification sensor RH (Front seat adjuster sub-assembly RH)* Occupant detection ECU
  1. *: The rear occupant classification sensor LH and RH are built into the separate type front seat cushion spring assembly RH or front seat adjuster sub-assembly RH.

Scheme 209

Scheme 209: WIRING DIAGRAM
Scheme 209: WIRING DIAGRAM

Scheme 210

Scheme 210
Scheme 210
  1. for TMMMS Made
  2. for TMMC Made

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

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

DTC No.Detection ItemDTC Detection ConditionTrouble Area
B1771Passenger Side Buckle Switch Circuit MalfunctionThe occupant detection ECU detects a line short, short to ground or B+, or an open in the passenger side buckle switch circuit. Passenger side buckle switch malfunction Occupant detection ECU malfunctionFront seat wire RH Passenger side buckle switch (Front seat inner belt assembly RH) Occupant detection ECU

Scheme 211

Scheme 211: WIRING DIAGRAM
Scheme 211: WIRING DIAGRAM

The occupant classification system detects the front passenger seat condition. It then displays the instrument panel passenger airbag assembly and front seat airbag sub-assembly RH condition (activated/not activated) using 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 indicate ON/OFF depending on the conditions listed below.

Front Passenger Seat ConditionPassenger Airbag ON/OFF IndicatorSRS Warning Light
ON IndicatorOFF Indicator
VacantOFFONOFF
Adult is seatedONOFFOFF
Child is seatedOFFONOFF
Child restraint system is installed
Occupant classification system failureOFFONON

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