21-2x

SRS DTC Troubleshooting: 21-1x, 21-2x (x can be 0 thru 9 or A thru F)

DTC 21-1x ("x" can be 0 thru 9 or A thru F):Open in Driver's Seat Belt Tensioner

DTC 21-2x ("x" can be 0 thru 9 or A thru F):Increased Resistance in Driver's Seat Belt Tensioner

Special Tools Required

- SRS inflator simulator 07SAZ-TB4011A
- SRS simulator lead K 070AZ-SNAA200
NOTE: Before doing this troubleshooting procedure, review SRS Precautions and Procedures Service and Repair, General Troubleshooting Information Initial Inspection and Diagnostic Overview, and Battery Terminal Disconnection and Reconnection. Procedures

1. Clear the DTC memory. Initial Inspection and Diagnostic Overview

2. Turn the ignition switch to 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 or 21-2x indicated?
YES - Go to step 3.

NO - Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. Initial Inspection and Diagnostic Overview If another DTC is indicated, troubleshoot the DTC.


3. Turn the ignition switch to LOCK (0). Disconnect the negative cable from the battery, then wait for 3 minutes.

4. Disconnect the floor wire harness 4P connector (A) from the driver's seat belt tensioner.

5. Connect the SRS inflator simulator (2 Ohms connectors) and simulator lead K to the floor wire harness.






6. Reconnect the negative cable to the battery.

7. Clear the DTC memory.

8. Read the DTC. Initial Inspection and Diagnostic Overview

Is DTC 21-1x or 21-2x indicated?
YES - Go to step 9.

NO - Open or increased resistance in the driver's seat belt tensioner; replace the driver's seat belt. Front Seat Belt Replacement


9. Turn the ignition switch to LOCK (0). Disconnect the negative cable from the battery, then wait for 3 minutes.

10. Disconnect the front passenger's seat belt tensioner 4P connector. Service and Repair

11. Disconnect SRS unit connector B (28P) from the SRS unit. Service and Repair

12. Measure the resistance between the terminals No. 1 and the No. 2 of SRS unit connector B (28P). There should be 2.0-3.0 Ohms.

Is 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. SRS Unit Replacement

NO - Open or increased resistance in the floor wire harness; replace the floor wire harness.