SRS DTC Troubleshooting: 21-9x
DTC 21-9x (‘‘x'' can be 0 thru 9 or A thru F):
Short to Ground in Left Side Seat Belt Tensioner
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 21-9x 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.
Is DTC 21-9x indicated?
YES -
Go to Step 9 .
NO -
Short to ground 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 the simulator lead from the floor wire harness.
  1. Check resistance between the No. 1 terminal of SRS unit connector B (28P) and body ground, and between the No. 2 terminal and body ground. There should be an open circuit or at least 1 MΩ.
Is the resistance as specified?
YES -
Faulty SRS unit or poor connection at SRS unit connector B (28P) and the SRS unit. Check the connection; if the connection is OK, replace the SRS unit. ■
NO -
Short to ground in the floor wire harness; replace the floor wire harness.■