SRS DTC Troubleshooting: 21-1x
DTC 21-1x (‘‘x'' can be 0 thru 9 or A thru F):
Open or Increased Resistance in Left Side Seat Belt Tensioner
Special Tools Required

SRS inflator simulator
 07SAZ-TB4011A

SRS simulator lead K
 070AZ-SNA0200
NOTE: Before doing this troubleshooting procedure, review SRS Precautions and Procedures.
  1. Erase the DTC memory.
  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 21-1x 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 floor wire harness 4P connector (A) from the driver's seat belt tensioner.
  1. Connect the SRS inflator simulator (2 Ω connectors) and simulator lead K to the floor wire harness.
  1. Reconnect the negative cable to the battery.
  1. Erase the DTC memory.
  1. Read the DTC.
Is DTC 21-1x indicated?
YES -
Go to Step 9 .
NO -
Open or increased resistance in the left side seat belt tensioner; replace the left side seat belt. ■
  1. Turn the ignition switch OFF. Disconnect the negative cable from the battery, and wait for 3 minutes.
  1. Disconnect both seat belt buckle tensioner connectors and the right side seat belt tensioner connector.
  1. Disconnect SRS unit connector B (28P) from the SRS unit.