DTC B0021-2B (2014 2015 2016)

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 that they 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 (2016), or Battery Terminal Disconnection and Reconnection (2014 2015) .
• Before replacing the SRS unit, check the SRS unit software version with the HDS. If the software version is not the latest, update the SRS unit software , and retest.

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 driver's side airbag inflator
   B0028-2B Short to another wire harness in the front passenger's 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
   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, or B0072-2B 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 lines)

   -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) - Refer to: SRS Unit Removal and Installation

   - 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)
   	Test point 1		Test point 2
   	Test circuits	From terminal	Test circuits	To terminal
   B0020-2B	LCA1+	No. 1	LSA+	No. 5
   	LCA1-	No. 2	LSA-	No. 6
   B0028-2B	LCA1+	No. 1	RSA+	No. 3
   	LCA1-	No. 2	RSA-	No. 4
   B0029-2B	LCA1+	No. 1	RCA1+	No. 12
   	LCA1-	No. 2	RCA1-	No. 13

   DTC	SRS unit connector B (39P)
   	Test point 1		Test point 2
   	Test circuits	From terminal	Test circuits	To terminal
   B0070-2B	LCA1+	No. 1	LRP+	No. 24
   	LCA1-	No. 2	LRP-	No. 25
   B0072-2B	LCA1+	No. 1	RRP+	No. 22
   	LCA1-	No. 2	RRP-	No. 23

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Short to another wire in the floor side 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, replace the SRS unit - Refer to: SRS Unit Removal and Installation, . If the DTC does not clear, replace the floor wire harness.