DTC B1653/35: Seat Position Airbag Sensor Circuit Malfunction: Procedure

1. Turn the ignition switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Check that the connectors are properly connected to the center airbag sensor assembly and the seat position sensor.

   OK

   The connectors are properly connected.

NG → CONNECT CONNECTORS PROPERLY 

OK: Go to next step 

1. Disconnect the connectors from the center airbag sensor assembly and the seat position sensor.
2. Check that the connectors (on the center airbag sensor assembly side and seat position sensor side) are not damaged.

   OK

   The connectors are not deformed or damaged.

NG → REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

Fig 1: Checking Seat Position Sensor Circuit (Center Airbag Sensor Assembly - Seat Position Sensor)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   1 - Body ground	Ignition switch ON	Below 1 V
   2 - Body ground	Ignition switch ON	Below 1 V

4. Turn the ignition switch off.
5. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
6. Using a service wire, connect terminals 17 and 9 of connector B.
   NOTE:

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

7. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1 - 2	Always	Below 1 Ω

8. Disconnect the service wire from connector B.
9. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1 - 2	Always	1 MΩ or higher
   1 - Body ground	Always	1 MΩ or higher
   2 - Body ground	Always	1 MΩ or higher

NG → See step   7 

OK: Go to next step 

1. Connect the connectors to the center airbag sensor assembly and the seat position sensor.
   Fig 2: Checking Center Airbag Sensor Assembly & Seat Position Sensor Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
3. Turn the ignition switch to ON, and wait for at least 60 seconds.
4. Clear the DTCs stored. Refer to DTC CHECK / CLEAR .
5. Turn the ignition switch off.
6. Turn the ignition switch to ON, and wait for at least 60 seconds.
7. Check for DTCs. Refer to DTC CHECK / CLEAR .

   OK

   DTC B1653/35 is not output.

   TEXT IN ILLUSTRATION
   
   

   *1	Seat Position Sensor
   *2	Center Airbag Sensor Assembly

   HINT: 

   Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.

NG → See step   5 

OK → See step   8 

1. Turn the ignition switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Replace the seat position sensor. Refer to REMOVAL .

   HINT: 

   Perform inspection using parts from a normal vehicle if possible.

NEXT: Go to next step 

1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
   Fig 3: Checking Center Airbag Sensor Assembly & Seat Position Sensor Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch to ON, and wait for at least 60 seconds.
3. Clear the DTCs. Refer to DTC CHECK / CLEAR .
4. Turn the ignition switch off.
5. Turn the ignition switch to ON, and wait for at least 60 seconds.
6. Check for DTCs. Refer to DTC CHECK / CLEAR .

   OK

   DTC B1653/35 is not output.

   TEXT IN ILLUSTRATION
   
   

   *1	Seat Position Sensor
   *2	Center Airbag Sensor Assembly

   HINT: 

   Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.

NG → See step   9 

OK → END 

Fig 4: Checking Floor Wire (Center Airbag Sensor - Front Seat Inner Belt LH)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the floor wire connector from the front seat inner belt assembly LH.
2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
3. Turn the ignition switch to ON.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   G45-4 (LSP+) - Body ground	Ignition switch ON	Below 1 V
   G45-3 (LSP-) - Body ground	Ignition switch ON	Below 1 V

5. Turn the ignition switch off.
6. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
7. Using a service wire, connect terminals 17 and 9 of connector B.
   NOTE:

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

8. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G45-4 (LSP+) - G45-3 (LSP-)	Always	Below 1 Ω

9. Disconnect the service wire from connector B.
10. Measure the resistance according to the value(s) in the table below.

    Standard Resistance

    Tester Connection	Condition	Specified Condition
    G45-4 (LSP+) - G45-3 (LSP-)	Always	1 MΩ or higher
    G45-4 (LSP+) - Body ground	Always	1 MΩ or higher
    G45-3 (LSP-) - Body ground	Always	1 MΩ or higher

NG → REPLACE FLOOR WIRE 

OK → See step   10