DTC B1635: Curtain Shield Airbag Sensor (LH); DTC B1637: Curtain Shield Airbag Sensor Lost Communication (LH) [10/2020 - 11/2021]: Procedure

1. Turn the power switch on (IG), and wait for at least 60 seconds.
2. Clear the DTCs stored in memory.

   Refer to DTC CHECK / CLEAR [10/2020 - 10/2023]

   Body Electrical > SRS Airbag > Clear DTCs 

3. Turn the power switch off.
4. Turn the power switch on (IG), and wait for at least 60 seconds.
5. Check for DTCs.

   Refer to DTC CHECK / CLEAR [10/2020 - 10/2023]

   Body Electrical > SRS Airbag > Trouble Codes 

   Result

   Proceed to
   DTC B1635 or B1637 is output
   DTC B1635 and B1637 are not output

   HINT: 

   Codes other than DTC B1635 and B1637 may be output at this time, but they are not related to this check.

Result: 

DTC B1635 and B1637 are not output 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2020 - 11/2021] 

Result: 

DTC B1635 or B1637 is output 

See step  2

1. Turn the power switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	Rear Airbag Sensor RH
   *2	Airbag ECU Assembly

2. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 60 seconds.
3. Interchange the rear airbag sensor LH with RH and connect the connectors to them.
4. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
5. Turn the power switch on (IG), and wait for at least 60 seconds.
6. Clear the DTCs stored in memory.

   Refer to DTC CHECK / CLEAR [10/2020 - 10/2023]

   Body Electrical > SRS Airbag > Clear DTCs 

7. Turn the power switch off.
8. Turn the power switch on (IG), and wait for at least 60 seconds.
9. Check for DTCs.

   Refer to DTC CHECK / CLEAR [10/2020 - 10/2023]

   Body Electrical > SRS Airbag > Trouble Codes 

   Result

   Proceed to
   DTC B1630 or B1632 is output
   DTC B1635 or B1637 is output
   DTC B1630, B1632, B1635 and B1637 are not output

   HINT: 

   Codes other than DTC B1630, B1632, B1635 and B1637 may be output at this time, but they are not related to this check.

10. Turn the power switch off.
11. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 60 seconds.
12. Return the rear airbag sensor RH and LH to their original positions and connect the connectors to them.

Result: 

DTC B1630 or B1632 is output 

REPLACE REAR AIRBAG SENSOR LH. Refer to  REMOVAL [10/2020 - 11/2021] 

Result: 

DTC B1635 or B1637 is output 

REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [10/2020 - 11/2021] 

Result: 

DTC B1630, B1632, B1635 and B1637 are not output 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2020 - 11/2021]