Occupant Classification System (Diagnostic Codes & Symptom Tests): Overview Scion xD I

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.

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1771 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTC cannot be read.

Scheme 270

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

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

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1780 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTC cannot be read.

Scheme 271

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

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

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1781 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTC cannot be read.

Scheme 272

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

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

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1782 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

Scheme 273

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

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

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1783 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

Scheme 274

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

DTC B1785 is also set when the front seat frame with adjuster RH is subjected to a strong impact, even if an actual accident has not occurred.

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 conducting the zero point calibration and sensitivity check.

Therefore, if DTC B1785 is set, first perform the zero point calibration and sensitivity check.

HINT

1. When DTC B1650/32 is set as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1785 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

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

DTC B1786 is also set when the front seat frame with adjuster RH is subjected to a strong impact, even if an actual accident has not occurred.

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 conducting the zero point calibration and sensitivity check.

Therefore, if DTC B1786 is set, first perform the zero point calibration and sensitivity check.

HINT

1. When DTC B1650/32 is set as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1786 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

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

DTC B1787 is also set when the front seat frame with adjuster RH is subjected to a strong impact, even if an actual accident has not occurred.

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 conducting the zero point calibration and sensitivity check.

Therefore, if DTC B1787 is output, first perform the zero point calibration and sensitivity check.

HINT

1. When DTC B1650/32 is set as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1787 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

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

DTC B1788 is also set when the front seat frame with adjuster RH is subjected to a strong impact, even if an actual accident has not occurred.

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 conducting the zero point calibration and sensitivity check.

Therefore, if DTC B1788 is output, first perform the zero point calibration and sensitivity check.

HINT

1. When DTC B1650/32 is set as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1788 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

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

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

HINT

1. When DTC B1630/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1790 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

Scheme 275

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

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

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1793 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

Scheme 276

DTC B1794 is set when a malfunction is detected in the occupant classification ECU.

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1794 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

Scheme 277

Scheme 278

1. CHECK FOR DTC Turn the ignition switch ON, and wait for at least 60 seconds. Clear any DTCs stored in the memory. Refer to «DTC CHECK / CLEAR»(ref-388797-S14360807342011031100000) . HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor. Use a Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared. Turn the ignition switch off, and wait for at least 10 seconds. Turn the ignition switch ON, and wait for at least 60 seconds. Using the Techstream, check for DTCs of the occupant classification ECU. Refer to «DTC CHECK / CLEAR»(ref-388797-S14360807342011031100000) . OK DTC B1794 is not output. HINT: DTCs other than DTC B1794 may be output at this time, but they are not related to this check. NG --> See step 2 OK --> See step 9
2. CHECK CONNECTION OF CONNECTOR Turn the ignition switch off. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds. Check that the connectors are properly connected to the center airbag sensor, occupant classification sensors and occupant classification ECU. OK Connectors are properly connected. NG --> CONNECT CONNECTOR OK: Go to next step
3. CHECK CONNECTOR Check that the connectors (on the occupant classification ECU side) are not damaged. Refer to «ELECTRONIC CIRCUIT INSPECTION PROCEDURE»(ref-388639-S24992445372011031100000) . OK Connectors are not deformed or damaged. NG --> REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (SOURCE VOLTAGE) Turn the ignition switch off. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds. Disconnect the connector from the occupant classification ECU. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds. Turn the ignition switch ON, and wait for at least 60 seconds. Measure the resistance and voltage according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition L27-3 (GND) - Body ground Always Below 1 ohms Standard voltage Tester Connection Switch Condition Specified Condition L27-1 (+B) - Body ground Ignition switch ON 11 to 14 V L27-7 (IG) - Body ground NG --> REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. CHECK FOR DTC Turn the ignition switch off. 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, and wait for at least 2 seconds. Turn the ignition switch ON, and wait for at least 60 seconds. Clear any DTCs stored in the memory. Refer to «DTC CHECK / CLEAR»(ref-388797-S14360807342011031100000) . HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor. Use a Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared. Turn the ignition switch off, and wait for at least 10 seconds. Turn the ignition switch ON, and wait for at least 60 seconds. Using the Techstream, check for DTCs of the occupant classification ECU. Refer to «DTC CHECK / CLEAR»(ref-388797-S14360807342011031100000) . OK DTC B1794 is not output. HINT: DTCs other than DTC B1794 may be output at this time, but they are not related to this check. NG --> See step 6 OK --> See step 9
6. REPLACE OCCUPANT CLASSIFICATION ECU Turn the ignition switch off. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds. Replace the occupant classification ECU. Refer to «REMOVAL»(ref-388788-S33890896262011031100000) . HINT: Perform the inspection using parts from a normal vehicle when possible. NEXT: Go to next step
7. PERFORM ZERO POINT CALIBRATION Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds. Connect a Techstream to the DLC3. Turn the ignition switch ON, and wait for at least 60 seconds. Using the Techstream, perform the zero point calibration. Refer to «INITIALIZATION»(ref-388797-S12360539702011031100000) . NEXT: Go to next step
8. PERFORM SENSITIVITY CHECK Using a Techstream, perform the sensitivity check. Refer to «INITIALIZATION»(ref-388797-S12360539702011031100000) . Standard range 27 to 33 kg (59.5 to 72.8 lb) NEXT --> END
9. USE SIMULATION METHOD TO CHECK. Refer to «DIAGNOSIS SYSTEM»(ref-388797-S24153039102011031100000)

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

Troubleshoot DTC B1771 first when both DTCs B1771 and B1795 are present.

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1795 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

During sleep mode, the occupant classification ECU monitors 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 set.

HINT

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1796 of the occupant classification system.
2. Use a Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

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

HINT

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