DTC B0021-1A:Decreased Resistance In The Left Side Curtain Airbag First Inflator (2014 2015)

DTC B0021-1A 

Special Tools Required 

SRS Short Canceller 070AZ-SAA0100 

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 12 VOLT BATTERY TERMINAL DISCONNECTION AND RECONNECTION .
• 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
   B0021-1A: Decreased resistance in the left side curtain airbag first inflator

   Is DTC B0021-1A 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. Left side curtain airbag inflator check

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

   - 2. Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

   - 3. Remove the headliner.

   - 4. Disconnect the following connector.

   LEFT SIDE CURTAIN AIRBAG INFLATOR 2P CONNECTOR (ON THE LEFT SIDE WIRE HARNESS)

   - 5. Reconnect the negative cable to the 12 volt battery.

   - 6. Clear the DTCs with the HDS.

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

   - 8. Check for DTCs with the HDS.

   DTC Description	DTC
   B0021-1A Decreased resistance in the left side curtain airbag first inflator

   Is DTC B0021-1A indicated?

   YES 

   Go to step 3.

   NO 

   Faulty left side curtain airbag inflator; REPLACE THE LEFT SIDE CURTAIN AIRBAG , then clear the DTC.

3. Shorted wire check (LCA+ line to LCA- line)

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

   - 2. Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

   - 3. Disconnect the following connector.

   SRS UNIT CONNECTOR B (39P) :Decreased Resistance in the Left Side Curtain Airbag First Inflator

   - 4. Connect the SRS short canceller to SRS unit connector B (39P) terminals No. 1 and No. 2.

   - 5. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Left side curtain airbag inflator 2P connector (on the left side wire harness): disconnected
   	SRS unit connector B (39P): disconnected
   	SRS unit connector B (39P) No. 1 and No. 2: connected to SRS short canceller
   Test circuit	LCA+, LCA-
   Test point 1	SRS unit connector B (39P) No. 1
   Test point 2	SRS unit connector B (39P) No. 2

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

   Is there an open circuit, or at least 1 MΩ?

   YES 

   The LCA+ and LCA- wires are OK. REPLACE THE SRS UNIT .

   NO 

   Short to another wire in the left or right side wire harness; replace the faulty harness, then clear the DTC.