SRS DTC Troubleshooting: 12-1x, 12-4x
DTC 12-1x (‘‘x'' can be 0 thru 9 or A thru F):
Open or Increased Resistance in Driver's Airbag First Inflator (RHD type)
DTC 12-4x (‘‘x'' can be 0 thru 9 or A thru F):
Open or Increased Resistance in Driver's Airbag Second Inflator (RHD type)
Special Tools Required
  1. Turn the ignition switch ON (II), and check that the SRS indicator comes on for about 6 seconds and then goes off.
Does the SRS indicator stay on, and is DTC 12-1x or 12-4x indicated?
YES -
Go to Step 3 .
NO -
Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. If another DTC is indicated, go to the DTC Troubleshooting Index.
  1. Turn the ignition switch OFF. Disconnect the negative cable from the battery, and wait for 3 minutes.
  1. Disconnect the driver's airbag 4P connector (A) from the cable reel.
  1. Connect the SRS inflator simulator (2 Ω connectors) and simulator lead J to the cable reel.
  1. Reconnect the negative cable to the battery.
  1. Erase the DTC memory.
Is DTC 12-1x or 12-4x indicated?
YES -
Go to Step 9 .
NO -
Open or increased resistance in the driver's airbag inflator; replace the driver's airbag. ■
  1. Turn the ignition switch OFF. Disconnect the negative cable from the battery, and wait for 3 minutes.
  1. Disconnect the combination switch wire harness 4P connector (A) from the cable reel.
  1. Connect the SRS inflator simulator (2 Ω connectors) and the simulator lead to the combination switch wire harness.
  1. Reconnect the negative cable to the battery.
  1. Erase the DTC memory.
  1. Read the DTC.
Is DTC 12-1x or 12-4x indicated?
YES -
Go to Step 15 .
NO -
Open or increased resistance in the cable reel; replace the cable reel. ■
  1. Turn the ignition switch OFF. Disconnect the negative cable from the battery, and wait for 3 minutes.
  1. Disconnect SRS unit connector A (28P) from the SRS unit. Do not disconnect the simulator lead from the combination switch wire harness 4P connector.
  1. Disconnect the SRS inflator simulator from the SRS simulator lead.
  1. Check resistance between the terminals of both SRS simulator leads. There should be 1 Ω or less.
Is the resistance as specified?
YES -
Faulty SRS unit or poor connection at SRS unit connector A (28P) and the SRS unit. Check the connection between the connector and the SRS unit. If the connection is OK, replace the SRS unit. ■
NO -
Open or increased resistance in the combination switch wire harness; replace the combination switch wire harness.■