DTC B1650/32: Occupant Classification System Malfunction: Procedure

1. Turn the ignition switch on (IG).
2. Using Techstream, check the DTCs of the occupant classification ECU. Refer to DTC CHECK / CLEAR .

NG → See step   12 

OK: Go to next step 

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 occupant classification ECU. Also check that the connectors that link the front seat wire RH and floor wire are properly connected.

   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 and occupant classification ECU. Also disconnect the connectors that link the front seat wire RH and floor wire.
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 that link the front seat wire RH and floor wire.
   Fig 1: Identifying Occupant Classifications System Circuit (Open)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using SST, connect terminals 16 (FSR+) and 24 (FSR-) of connector B.
   NOTE:

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

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   a3-8 (FSR+) - a3-4 (FSR-)	Always	Below 1 Ω

NG → See step   7 

OK: Go to next step 

1. Disconnect SST from connector B.
   Fig 2: Identifying Occupant Classification System Circuit (Short)

   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
   a3-8 (FSR+) - a3-4 (FSR-)	Always	1 MΩ or higher

NG → See step   8 

OK: Go to next step 

1. Connect the cable to the negative (-) battery terminal.
   Fig 3: Identifying Occupant Classification System Circuit (Short To B+)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   a3-8 (FSR+) - Body ground	Ignition switch on (IG)	Below 1 V
   a3-4 (FSR-) - Body ground	Ignition switch on (IG)	Below 1 V

NG → See step   9 

OK: Go to next step 

1. Turn the ignition switch off.
   Fig 4: Identifying Occupant Classification System Circuit (Short To Ground)

   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
   a3-8 (FSR+) - Body ground	Always	1 MΩ or higher
   a3-4 (FSR-) - Body ground	Always	1 MΩ or higher

   HINT: 

   After replacing the center airbag sensor assembly, check for DTCs of the center airbag sensor assembly. If the DTC B1650/32 is detected, replace the occupant classification ECU. Refer to REMOVAL and perform "zero point calibration" and "sensitivity check" of the occupant classification system. Refer to INITIALIZATION .

NG → See step   10 

OK → See step   11 

1. Disconnect the front seat wire RH connector from the floor wire.
   Fig 5: Identifying Floor Wire (Open)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT: 

   SST has already been inserted into connector B.

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Na1-1 (FSR+) - Na1-4 (FSR-)	Always	Below 1 Ω

NG → REPLACE FLOOR WIRE 

OK → REPLACE FRONT SEAT WIRE RH 

1. Disconnect the front seat wire RH connector from the floor wire.
   Fig 6: Identifying Floor Wire (Short)

   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
   Na1-1 (FSR+) - Na1-4 (FSR-)	Always	1 MΩ or higher

NG → REPLACE FLOOR WIRE 

OK → REPLACE FRONT SEAT WIRE RH 

1. Turn the ignition switch off.
   Fig 7: Identifying Floor Wire (Short To B+)

   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 front seat wire RH connector from the floor wire.
4. Connect the cable to the negative (-) battery terminal.
5. Turn the ignition switch on (IG).
6. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   Na1-1 (FSR+) - Body ground	Ignition switch on (IG)	Below 1 V
   Na1-4 (FSR-) - Body ground	Ignition switch on (IG)	Below 1 V

NG → REPLACE FLOOR WIRE 

OK → REPLACE FRONT SEAT WIRE RH 

1. Disconnect the front seat wire RH connector from the floor wire.
   Fig 8: Identifying Floor Wire (Short To Ground)

   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
   Na1-1 (FSR+) - Body ground	Always	1 MΩ or higher
   Na1-4 (FSR-) - Body ground	Always	1 MΩ or higher

NG → REPLACE FLOOR WIRE 

OK → REPLACE FRONT SEAT WIRE RH