DTC Troubleshooting: B0021-1A (KA/KC models)

DTC Troubleshooting: B0021-1A

DTC B0021-1A:Decreased Resistance in the Left Side Curtain Airbag First Inflator

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 were properly installed.
	Before doing this troubleshooting procedure, review SRS Precautions and Procedures, General Troubleshooting Information, and 12 Volt Battery Terminal Disconnection and Reconnection.

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

Problem verification:

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.?

Left side curtain airbag inflator check:

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 floor 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

Short to another wire in the left side curtain airbag inflator; replace the left side curtain airbag, then clear the DTC.?

Shorted wire check (LCA? line to LCA? line):

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)

?4.	Connect the SRS short canceller to SRS unit connector B (39P) terminals No. 9 and No. 10.

?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 floor wire harness): disconnected
	SRS unit connector B (39P): disconnected
	SRS unit connector B (39P) No. 9 and No. 10: connected to SRS short canceller
Test point 1	SRS unit connector B (39P) No. 9
Test point 2	SRS unit connector B (39P) No. 10

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


	YES

The LCA? and LCA? 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. If the DTC does not clear, replace the floor wire harness.?


	NO

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