Passenger side buckle switch circuit malfunction

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

• If troubleshooting (wire harness inspection) is difficult to perform, remove the front passenger seat installation bolts to see the undersurface of the seat cushion.
• In the above case, hold the seat so that it does not tip over. Holding the seat for a long period of time may cause a problem, such as seat rail deformation. Hold the seat up only for as long as necessary.

1. 1
   Check for dtc
2. 2
   Turn the ignition switch on.
3. 3
   Clear the dtcs (see page rs-249).

First clear dtcs stored in the occupant classification ecu and then in the center airbag sensor.

1. 1
   Turn the ignition switch off.
2. 2
   Turn the ignition switch on.
3. 3
   Check the dtcs (see page rs-249).

Dtcs other than dtc b1771 may be output at this time, but they are not related to this check.

1. 1
   Check connection of connector
2. 2
   Turn the ignition switch off.
3. 3
   Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
4. 4
   Check that the connectors are properly connected to the occupant classification ecu and the front seat inner belt rh.

3. Check floor wire (to b+)

1. 1
   Disconnect the connectors from the occupant classification ecu and the front seat inner belt rh.
2. 2
   Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
3. 3
   Turn the ignition switch on.
4. 4
   Measure the voltage of the wire harness side connector.

Standard voltage

4. Check floor wire (for open)

1. 1
   Turn the ignition switch off.
2. 2
   Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds
3. 3
   Using a service wire, connect terminals l2-2 and l2-1 of connector c.

Do not forcibly insert a service wire into the terminals of the connector when connecting them.

4. Measure the resistance of the wire harness side connectors.

Standard resistance

5. Check floor wire (for short)

1. 1
   Disconnect the service wire from connector c.
2. 2
   Measure the resistance of the wire harness side connector.

Standard resistance

6. Check floor wire (to ground)

1. Measure the resistance of the wire harness side connector.

Standard resistance

1. 1
   Check for dtc
2. 2
   Connect the connectors to the occupant classification ecu and the front seat inner belt rh.
3. 3
   Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
4. 4
   Turn the ignition switch on.
5. 5
   Clear the dtcs (see page rs-249).

First clear dtcs stored in the occupant classification ecu and then in the center airbag sensor.

1. 1
   Turn the ignition switch off.
2. 2
   Turn the ignition switch on.
3. 3
   Check the dtcs (see page rs-249).

Dtcs other than dtc b1771 may be output at this time, but they are not related to this check.

1. 1
   Replace front seat inner belt assembly rh
2. 2
   Turn the ignition switch off.
3. 3
   Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
4. 4
   Replace the front seat inner belt rh (see page sb-21).

Perform the inspection using parts from a normal vehicle if possible.

1. 1
   Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
2. 2
   Turn the ignition switch on.
3. 3
   Clear the dtcs (see page rs-249).

First clear dtcs stored in the occupant classification ecu and then in the center airbag sensor.

1. 1
   Turn the ignition switch off.
2. 2
   Turn the ignition switch on.
3. 3
   Check the dtcs (see page rs-249).

Dtcs other than dtc b1771 may be output at this time, but they are not related to this check.

1. 1
   Replace occupant classification ecu
2. 2
   Turn the ignition switch off.
3. 3
   Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
4. 4
   Replace the occupant classification ecu (see page rs- 392).

   

1. 1
   Perform zero point calibration
2. 2
   Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
3. 3
   Connect the intelligent tester (with can vim) to the dlc3.
4. 4
   Turn the ignition switch on.
5. 5
   Using the intelligent tester, perform the zero point calibration (see page rs-241).

1. 1
   Perform sensitivity check
2. 2
   Using the intelligent tester, perform the sensitivity check (see page rs-241).