DTC B0021-2B (2017 2018 2019 2020)

DTC B0021-2B  : Short to Another Wire Harness in the Left Side Curtain Airbag First Inflator

NOTE: Before doing this troubleshooting procedure, find out if the vehicle was in a collision. If so, verify that all the required components were replaced with new components of the correct part number and were properly installed .
• Before doing this troubleshooting procedure, review SRS Precautions and Procedures , General Troubleshooting Information , and Battery Terminal Disconnection and Reconnection. - Refer to: Battery Terminal Disconnection and Reconnection .

DTC (SRS)

1. Problem verification

   -1. Clear the DTCs with the HDS.

   - 2. Turn the vehicle to the ON mode, then wait for 10 seconds.

   - 3. Check for DTCs with the HDS.

   DTC Description	DTC
   B0021-2B Short to another wire harness in the left side curtain airbag first inflator

   Is DTC B0021-2B indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. If another DTC is indicated, troubleshoot the DTC.

2. DTC check

   -1. Check for DTCs with the HDS.

   DTC Description	DTC
   B0020-2B Short to another wire harness in the left side airbag inflator
   B0028-2B Short to another wire harness in the right side airbag inflator
   B0029-2B Short to another wire harness in the right side curtain airbag first inflator
   B0070-2B Short to another wire harness in the driver's seat belt tensioner
   B0072-2B Short to another wire harness in the front passenger's seat belt tensioner
   B007A-2B Short to another wire harness in the front passenger's seat belt outer lap tensioner
   B0021-2B Short to another wire harness in the left side curtain airbag first inflator

   Is DTC B0020-2B, B0028-2B, B0029-2B, B0070-2B, B0072-2B or B007A-2B indicated with DTC B0021-2B?

   YES 

   Go to step 3.

   NO 

   Short to another wire in the floor wire harness; replace the floor wire harness, then clear the DTC.

3. Shorted wire check (LCA1 lines to another line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the negative cable from the Battery, then wait at least 3 minutes.

   - 3. Disconnect the following connector.

   SRS unit connector B (39P)

   - 4. Check for continuity between test points 1 and 2 of SRS unit connector B (39P) according to table.

   Test condition	Vehicle OFF (LOCK) mode
   	SRS unit connector B (39P): disconnected

   DTC	SRS unit connector B (39P) - Refer to: SRS Unit Connector for Inputs and Outputs (2017 2018 2019 2020)
   	Test point 1	Test point 2
   	From terminal	To terminal
   B0020-2B	No. 9	No. 5
   	No. 10	No. 6
   B0028-2B	No. 9	No. 4
   	No. 10	No. 3
   B0029-2B	No. 9	No. 8
   	No. 10	No. 7

   DTC	SRS unit connector B (39P) - Refer to: SRS Unit Connector for Inputs and Outputs (2017 2018 2019 2020)
   	Test point 1	Test point 2
   	From terminal	To terminal
   B0070-2B	No. 9	No. 20
   	No. 10	No. 21
   B0072-2B	No. 9	No. 19
   	No. 10	No. 18
   B007A-2B	No. 9	No. 23
   	No. 10	No. 22

   Is there continuity?

   YES 

   Short to another wire in the floor wire harness; replace the floor wire harness, then clear the DTC.

   NO 

   The LCA1 wires are OK. Faulty SRS unit or poor connection at SRS unit connector B (39P) and the SRS unit. Check the connection; if the connection is OK, check for any authorized service information related to the DTCs or symptoms you are troubleshooting or replace the SRS unit - Refer to: SRS Unit Removal and Installation (2017 2018 2019 2020) . If the DTC does not clear, replace the floor wire harness.