DESCRIPTION
The passenger side buckle switch circuit consists of the occupant classification ECU and the 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 when DTCs B1771 and B1795 are output simultaneously.
| DTC No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1771 | Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in passenger side buckle switch circuit for 2 seconds Passenger side buckle switch malfunction Occupant classification ECU malfunction | Floor wire Front seat inner belt assembly RH (Buckle switch RH) Occupant classification ECU |
Scheme 179
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 No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1780 | Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in 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 assembly RH (Front occupant classification sensor LH) Occupant classification ECU |
Scheme 180
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 No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1781 | Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in 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 assembly RH (Front occupant classification sensor RH) Occupant classification ECU |
Scheme 181
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 No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1782 | Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in 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 assembly RH (Rear occupant classification sensor LH) Occupant classification ECU |
Scheme 182
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 No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1783 | Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in 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 assembly RH (Rear occupant classification sensor RH) Occupant classification ECU |
Scheme 183
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 assembly RH is subjected to a strong impact, even if an actual accident does not occur.
However, when the front occupant classification sensor LH 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 No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1785 | Front seat assembly RH malfunction Occupant classification ECU malfunction Front occupant classification sensor LH detects large load | Occupant classification ECU Front seat assembly RH (Front occupant classification sensor LH) |
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 front occupant classification sensor RH 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 No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1786 | Front seat assembly RH malfunction Occupant classification ECU malfunction Front occupant classification sensor RH detects large load | Occupant classification ECU Front seat assembly RH (Front occupant classification sensor RH) |
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 rear occupant classification sensor LH 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 No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1787 | Front seat assembly RH malfunction Occupant classification ECU malfunction Rear occupant classification sensor LH detects large load | Occupant classification ECU Front seat assembly RH (Rear occupant classification sensor LH) |
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 assembly RH is subjected to a strong impact, even if an actual accident does not occur.
However, when the rear occupant classification sensor RH 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 No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| B1788 | Front seat assembly RH malfunction Occupant classification ECU malfunction Rear occupant classification sensor RH detects large load | Occupant classification ECU Front seat assembly RH (Rear occupant classification sensor RH) |
The center airbag sensor assembly communication circuit consists of the occupant classification ECU and the 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 Condition | Trouble Area |
|---|---|---|
| B1790 | Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in center airbag sensor assembly communication circuit for 2 seconds Center airbag sensor assembly malfunction Occupant classification ECU malfunction | Floor wire Occupant classification ECU Center airbag sensor assembly |
Scheme 184
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 No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1793 | Occupant classification ECU detects line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in occupant classification sensor power supply circuit for 2 seconds Occupant classification ECU malfunction | Front seat wire RH Front seat assembly RH (Occupant classification sensors) Occupant classification ECU |
Scheme 185
DTC B1794 is set when a malfunction is detected in the occupant classification ECU battery positive line.
| DTC No. | DTC Detecting Conditions | Trouble Areas |
|---|---|---|
| B1794 | Occupant classification ECU circuit malfunction Occupant classification ECU malfunction Occupant classification ECU detects short circuit to ground signal in passenger side buckle switch circuit for 2 seconds | Wire harness Occupant classification ECU |
Scheme 186
Scheme 187
- CHECK DTC Turn the ignition switch to the on position. Clear the DTCs stored in the memory. Refer to «DTC CHECK / CLEAR»(ref-394582-S41128750742011040800000) . HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly. Turn the ignition switch to the lock position, and wait for at least 10 seconds. Turn the ignition switch to the on position. Check the DTCs. Refer to «DTC CHECK / CLEAR»(ref-394582-S41128750742011040800000) . 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 CONNECTION OF CONNECTORS Turn the ignition switch to the lock position. Disconnect the negative (-) terminal cable from the battery, 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 CONNECTORS OK: Go to next step
- CHECK WIRE HARNESS (SOURCE VOLTAGE) Turn the ignition switch to the lock position. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds. Disconnect the J24 connector from the occupant classification ECU. Connect the negative (-) terminal cable to the battery. Turn the ignition switch to the on position. Measure the voltage. Standard voltage Tester Connection Condition Specified Condition J24-1 (+B) - Body ground Ignition switch on 11 to 14 V J24-7 (IG) - Body ground Ignition switch on 11 to 14 V Measure the resistance. Standard resistance Tester Connection Condition Specified Condition J24-3 (GND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - OCCUPANT CLASSIFICATION ECU) OK: Go to next step
- CHECK DTC Turn the ignition switch to the lock position. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds. Connect the connectors to the occupant classification ECU. Connect the negative (-) terminal cable to the battery. Turn the ignition switch to the on position. Clear any DTCs stored in the memory. Refer to «DTC CHECK / CLEAR»(ref-394582-S41128750742011040800000) . HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly. Turn the ignition switch to the lock position, and wait for at least 10 seconds. Turn the ignition switch to the on position. Using the Techstream, check for DTCs of the occupant classification ECU. Refer to «DTC CHECK / CLEAR»(ref-394582-S41128750742011040800000) . 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 to the lock position. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds. Replace the occupant classification ECU. Refer to «REMOVAL»(ref-394575-S11569932092011040800000) . HINT: Perform the inspection using parts from a normal vehicle when possible. NEXT: Go to next step
- PERFORM ZERO POINT CALIBRATION Connect the negative (-) terminal cable to the battery. Connect the Techstream to the DLC3. Turn the ignition switch to the on position. Using the Techstream, perform the zero point calibration. Refer to «INITIALIZATION»(ref-394582-S00858781662011040800000) . OK COMPLETED is displayed on the tester. NEXT: Go to next step
- PERFORM SENSITIVITY CHECK Using the Techstream, perform the sensitivity check. Refer to «INITIALIZATION»(ref-394582-S00858781662011040800000) . Confirm that nothing is placed on the passenger seat. Confirm that the beginning sensor reading is within the standard range. Standard range -3.2 to 3.2 kg (-7 to 7 lb) Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat. Confirm that the sensitivity is within the standard range. Standard range 27 to 33 kg (59.52 to 72.75 lb) HINT: When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used). NEXT --> END
DTC B1795 is recorded when a malfunction is detected in the occupant classification ECU.
| DTC No. | DTC Detecting Condition | Trouble Area |
|---|---|---|
| B1795 | Occupant classification ECU malfunction | Occupant classification ECU |
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 No. | DTC Detecting 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 |
|---|---|---|
| Vacant | OFF | OFF |
| Adult is seated | ON | OFF |
| Child is seated | OFF | ON |
| Child restraint system is set | OFF | ON |
| Front passenger occupant classification system failure | OFF | ON |
