DESCRIPTION
The passenger side buckle switch circuit consists of the occupant classification ECU and the front seat inner belt RH.
DTC B1771 is recorded when a malfunction is detected in the passenger side buckle switch circuit.
Troubleshoot DTC B1771 first when DTCs B1771 and B1795 are output simultaneously.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1771 | When one of following conditions is met: Occupant classification ECU detects line short signal, open signal, short to ground signal or short to B+ signal in the passenger side buckle switch circuit for 2 seconds Passenger side buckle switch malfunction Occupant classification ECU malfunction | Floor wire No. 2 Front seat inner belt RH (Buckle switch RH) Occupant classification ECU |
Scheme 277
The front occupant classification sensor LH circuit consists of the occupant classification ECU and the front occupant classification sensor LH.
DTC B1780 is recorded when a malfunction is detected in the front occupant classification sensor LH circuit.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1780 | When one of following conditions is met: Occupant classification ECU detects line short signal, open signal, short to ground signal or short to B+ signal in the front occupant classification sensor LH circuit for 2 seconds Front occupant classification sensor LH malfunction Occupant classification ECU malfunction | Front seat wire RH Front seat with adjuster frame assembly RH (Front occupant classification sensor LH) Occupant classification ECU |
Scheme 278
The front occupant classification sensor RH circuit consists of the occupant classification ECU and the front occupant classification sensor RH.
DTC B1781 is recorded when a malfunction is detected in the front occupant classification sensor RH circuit.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1781 | When one of following conditions is met: Occupant classification ECU detects line short signal, open signal, short to ground signal or short to B+ signal in the front occupant classification sensor RH circuit for 2 seconds Front occupant classification sensor RH malfunction Occupant classification ECU malfunction | Front seat wire RH Front seat with adjuster frame assembly RH (Front occupant classification sensor RH) Occupant classification ECU |
Scheme 279
The rear occupant classification sensor LH circuit consists of the occupant classification ECU and the rear occupant classification sensor LH.
DTC B1782 is recorded when a malfunction is detected in the rear occupant classification sensor LH circuit.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1782 | When one of following conditions is met: Occupant classification ECU detects line short signal, open signal, short to ground signal or short to B+ signal in the rear occupant classification sensor LH circuit for 2 seconds Rear occupant classification sensor LH malfunction Occupant classification ECU malfunction | Front seat wire RH Front seat with adjuster frame assembly RH (Rear occupant classification sensor LH) Occupant classification ECU |
Scheme 280
The rear occupant classification sensor RH circuit consists of the occupant classification ECU and the rear occupant classification sensor RH.
DTC B1783 is recorded when a malfunction is detected in the rear occupant classification sensor RH circuit.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1783 | When one of following conditions is met: Occupant classification ECU detects line short signal, open signal, short to ground signal or short to B+ signal in the rear occupant classification sensor RH circuit for 2 seconds Rear occupant classification sensor RH malfunction Occupant classification ECU malfunction | Front seat wire RH Front seat with adjuster frame assembly RH (Rear occupant classification sensor RH) Occupant classification ECU |
Scheme 281
DTC B1785 is output when the occupant classification ECU receives a collision detection signal sent by the front occupant classification sensor LH when an accident occurs.
DTC B1785 is also output when the front seat 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 performing the zero point calibration and sensitivity check.
Therefore, when DTC B1785 is output, first perform the zero point calibration and sensitivity check.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1785 | When one of following conditions is met: Front seat RH malfunction Occupant classification ECU malfunction Front occupant classification sensor LH detects large load | Occupant classification ECU Front seat with adjuster frame assembly RH (Front occupant classification sensor LH) |
Scheme 282
DTC B1786 is output when the occupant classification ECU receives a collision detection signal sent by the front occupant classification sensor RH when 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 performing the zero point calibration and sensitivity check.
Therefore, when DTC B1786 is output, first perform the zero point calibration and sensitivity check.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1786 | When one of following conditions is met: Front seat RH malfunction Occupant classification ECU malfunction Front occupant classification sensor RH detects large load | Occupant classification ECU Front seat with adjuster frame assembly RH (Front occupant classification sensor RH) |
Scheme 283
DTC B1787 is output when the occupant classification ECU receives a collision detection signal sent by the rear occupant classification sensor LH when 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 performing the zero point calibration and sensitivity check.
Therefore, when DTC B1787 is output, first perform the zero point calibration and sensitivity check.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1787 | When one of following conditions is met: Front seat RH malfunction Occupant classification ECU malfunction Rear occupant classification sensor LH detects large load | Occupant classification ECU Front seat with adjuster frame assembly RH (Rear occupant classification sensor LH) |
Scheme 284
DTC B1788 is output when the occupant classification ECU receives a collision detection signal sent by the rear occupant classification sensor RH when an accident occurs.
DTC B1788 is also output when the front seat 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 performing the zero point calibration and sensitivity check.
Therefore, when DTC B1788 is output, first perform the zero point calibration and sensitivity check.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1788 | When one of following conditions is met: Front seat RH malfunction Occupant classification ECU malfunction Rear occupant classification sensor RH detects large load | Occupant classification ECU Front seat with adjuster frame assembly RH (Rear occupant classification sensor RH) |
Scheme 285
The center airbag sensor communication circuit consists of the occupant classification ECU and the center airbag sensor.
DTC B1790 is recorded when a malfunction is detected in the center airbag sensor communication circuit.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1790 | When one of following conditions is met: Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the center airbag sensor assembly communication circuit for 2 seconds Center airbag sensor malfunction Occupant classification ECU malfunction | Floor wire No. 2 Occupant classification ECU Center airbag sensor |
Scheme 286
The occupant classification sensor power supply circuit consists of the occupant classification ECU and the occupant classification sensors.
DTC B1793 is recorded when a malfunction is detected in the occupant classification sensor power supply circuit.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1793 | When one of following conditions is met: Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the occupant classification sensor power supply circuit for 2 seconds Occupant classification ECU malfunction | Front seat wire RH Front seat with adjuster frame assembly RH (Occupant classification sensors) Occupant classification ECU |
Scheme 287
This circuit consists of the occupant classification ECU and the power source circuit (battery, fuse, wire harness).
DTC B1794 is set when a malfunction is detected in the occupant classification ECU battery positive line.
HINT
When DTC B1794 is output after switching the ignition switch off / ON / off 50 times in a row when a malfunction occurs in the power circuit for the occupant classification system, the DTC is output again when a malfunction is detected even once after being cleared, unless the normal system code is input.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1794 | When one of following conditions is met: The occupant classification ECU receives the ignition switch off to ON signal 50 times in a row when a malfunction occurs in the power circuit for the occupant classification ECU (OFF to ON to OFF should be counted as 1 time). Occupant classification ECU malfunction | Battery ECU-B fuse Wire harness Occupant classification ECU |
Scheme 288
Scheme 289
- CHECK FOR DTC Turn the ignition switch to ON. Clear the DTCs.Refer to «DTC CHECK / CLEAR»(ref-493544-S41275411502012081000000) . HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor. Turn the ignition switch off, and wait for at least 10 seconds. Turn the ignition switch to ON. Check the DTCs.Refer to «DTC CHECK / CLEAR»(ref-493544-S41275411502012081000000) . OK DTC B1794 is not output. HINT: DTCs other than B1794 may be output at this time, but they are not related to this check. OK --> USE SIMULATION METHOD TO CHECK NG: Go to next step
- CHECK FUSE (ECU-B) Check the ECU-B fuse. Standard resistance Below 1ohms NG --> REPLACE FUSE OK: Go to next step
- CHECK CONNECTION OF CONNECTOR Turn the ignition switch off. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds. Check that the connectors are properly connected to the occupant classification ECU. OK The connectors are properly connected. NG --> CONNECT CONNECTOR OK: Go to next step
- CHECK WIRE HARNESS (SOURCE VOLTAGE) Turn the ignition switch off. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds. Disconnect the L1 connector from the occupant classification ECU. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds. Measure the voltage of the wire harness side connector. Standard voltage Tester Connection Condition Specified Condition L1-1 (+B) - Body ground Always 11 to 14 V L1-7 (IG) - Body ground Ignition switch ON 11 to 14 V Turn the ignition switch off. Measure the resistance of the wire harness side connector. Standard resistance Tester Connection Specified Condition L1-3 (GND) - Body ground Below 1 ohms NG --> REPAIR OR REPLACE HARNESS AND CONNECTOR (BATTERY - OCCUPANT CLASSIFICATION ECU) OK: Go to next step
- CHECK FOR DTC Turn the ignition switch off. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds. Connect the connectors to the occupant classification ECU. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds. Turn the ignition switch to ON. Clear the DTCs.Refer to «DTC CHECK / CLEAR»(ref-493544-S41275411502012081000000) . HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor. Turn the ignition switch off, and wait for at least 10 seconds. Turn the ignition switch to ON. Using the Techstream, check for DTCs of the occupant classification ECU.Refer to «DTC CHECK / CLEAR»(ref-493544-S41275411502012081000000) . OK DTC B1794 is not output. HINT: DTCs other than B1794 may be output at this time, but they are not related to this check. OK --> USE SIMULATION METHOD TO CHECK NG: Go to next step
- REPLACE OCCUPANT CLASSIFICATION ECU Turn the ignition switch off. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds. Replace the occupant classification ECU.Refer to «COMPONENTS»(ref-493529-S17905650862012081000000) . NEXT: Go to next step
- PERFORM ZERO POINT CALIBRATION Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds. Connect the Techstream to the DLC3. Turn the ignition switch to ON. Using the Techstream, perform the zero point calibration.Refer to «INITIALIZATION»(ref-493544-S12284657172012081000000) . OK "Zero Point Calibration is complete." is displayed. NEXT: Go to next step
- PERFORM SENSITIVITY CHECK Using the Techstream, perform the sensitivity check.Refer to «INITIALIZATION»(ref-493544-S12284657172012081000000) . Standard value 27 to 33 kg (59.52 to 72.75 lb) NEXT --> END
DTC B1795 is recorded when a malfunction is detected in the occupant classification ECU.
Troubleshoot DTC B1771 first when DTC B1771 and B1795 are output simultaneously.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1795 | When one of following conditions is met: Occupant classification ECU circuit malfunction The occupant classification ECU receives a short circuit to ground signal in the passenger side buckle switch circuit for 2 seconds. Occupant classification ECU malfunction | Front seat inner belt RH Occupant classification ECU |
Scheme 290
During sleep mode, the occupant classification ECU reads the condition of each sensor while the ignition switch is off.
In this mode, if the occupant classification ECU detects an internal malfunction, DTC B1796 is output.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1796 | Occupant classification ECU malfunction | Occupant classification ECU |
The occupant classification system detects the front passenger seat condition and then indicates whether the front passenger airbag is activated or not through the passenger airbag ON/OFF indicator illumination.
The passenger airbag ON/OFF indicator illumination changes depending on the front passenger seat condition as shown in the table below.
| Front Passenger Seat Condition | ON Indicator | OFF Indicator |
|---|---|---|
| Adult is seated | ON | OFF |
| Child is seated | OFF | ON |
| Vacant | OFF | OFF |
| Occupant classification system failure | OFF | ON |
