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, front seat inner belt assembly LH and the seat position airbag sensor.

   OK

   The connectors are properly connected.

   HINT: 

   If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

4. Disconnect the connectors from the center airbag sensor assembly, front seat inner belt assembly LH and the seat position airbag sensor.
5. Check that the terminals of the connectors are not damaged.

   OK

   The terminals are not deformed or damaged.

NG → REPLACE WIRE HARNESS 

OK: Go to next step 

1. Connect the connectors to the front seat inner belt assembly LH and floor wire.
   Fig 1: Checking Seat Position Airbag Sensor Circuit Using SST (Open)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using SST, connect terminals 14 (LSP+) and 13 (LSP-) of connector B.
   NOTE:

   Do not forcibly insert SST into the terminals of the connector.

   • SST: 09843-18040 
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2 (LSP+) - 1 (LSP-)	Always	Below 1 Ω

NG → See step   10 

OK: Go to next step 

1. Disconnect SST from connector B.
   Fig 2: Checking Seat Position Airbag Sensor Circuit And Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2 (LSP+) - 1 (LSP-)	Always	1 MΩ or higher

NG → See step   11 

OK: Go to next step 

1. Connect the cable to the negative (-) battery terminal.
   Fig 3: Checking Seat Position Airbag Sensor Circuit And Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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
   2 (LSP+) - Body ground	Ignition switch ON	Below 1 V
   1 (LSP-) - Body ground	Ignition switch ON	Below 1 V

NG → See step   12 

OK: Go to next step 

1. Turn the ignition switch off.
   Fig 4: Checking Seat Position Airbag Sensor Circuit And Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

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

NG → See step   13 

OK: Go to next step 

1. Connect the connectors to the center airbag sensor assembly and the seat position airbag sensor.
   Fig 5: Checking Seat Position Airbag Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the cable to the negative (-) battery terminal.
3. Turn the ignition switch to ON, and wait for at least 60 seconds.
4. Clear the DTCs stored in the memory. 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.

   HINT: 

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

NG → See step   7 

OK → See step   9 

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 airbag sensor with a known good part. Refer to REMOVAL .

   HINT: 

   Perform the following inspection using known good parts from another vehicle if possible.

NEXT: Go to next step 

1. Connect the cable to the negative (-) battery terminal.
   Fig 6: Checking Center Airbag Sensor Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch to ON, and wait for at least 60 seconds.
3. Clear the DTCs stored in the memory. 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.

   HINT: 

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

NG → See step   14 

OK → END 

1. Disconnect the floor wire from the front seat inner belt assembly LH.

   HINT: 

   SST has already been inserted into connector B.

   Fig 7: Checking Floor Wire Using SST (Open)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L15-1 (LSP+) - L15-3 (LSP-)	Always	Below 1 Ω

NG → REPLACE FLOOR WIRE 

OK → See step   15 

1. Disconnect the floor wire from the front seat inner belt assembly LH.
   Fig 8: Checking Floor Wire And L15 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L15-1 (LSP+) - L15-3 (LSP-)	Always	1 MΩ or higher

NG → REPLACE FLOOR WIRE 

OK → See step   15 

1. Turn the ignition switch off.
   Fig 9: Checking Floor Wire And L15 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Disconnect the floor wire from the front seat inner belt assembly LH.
4. Connect the cable to the negative (-) battery terminal.
5. Turn the ignition switch to ON.
6. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   L15-1 (LSP+) - Body ground	Ignition switch ON	Below 1 V
   L15-3 (LSP-) - Body ground	Ignition switch ON	Below 1 V

NG → REPLACE FLOOR WIRE 

OK → See step   15 

1. Disconnect the floor wire from the front seat inner belt assembly LH.
   Fig 10: Checking Floor Wire And L15 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L15-1 (LSP+) - Body ground	Always	1 MΩ or higher
   L15-3 (LSP-) - Body ground	Always	1 MΩ or higher

NG → REPLACE FLOOR WIRE 

OK → See step   15