21-2x

SRS DTC Troubleshooting: 21-1x, 21-2x

DTC 21-1x ("x" can be 0 thru 9 or A thru F):

Open in the Driver's Seat Belt Tensioner

DTC 21-2x ("x" can be 0 thru 9 or A thru F):

Increased Resistance in the Driver's Seat Belt Tensioner

Special Tools Required

- SRS Inflator Simulator 07SAZ-TB4011A
- SRS Simulator Lead K 070AZ-SNAA200
- 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 that they were properly installed Service and Repair.
- Before doing this troubleshooting procedure, review SRS Precautions and Procedures Service and Repair, General Troubleshooting Information Reading and Clearing Diagnostic Trouble Codes, and Battery Terminal Disconnection and Reconnection Battery Terminal Disconnection And Reconnection.
- Before replacing the SRS unit, check the SRS unit software version with the HDS. If the software version is not the latest, update the SRS unit software Testing and Inspection, and retest.

1. Clear the DTC memory.

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. If another DTC is indicated, troubleshoot the DTC.

3. Turn the ignition switch to LOCK (0).

4. Disconnect the negative cable from the battery, then wait at least 3 minutes.

5. Remove the B-pillar lower trim, then disconnect the floor wire harness 4P connector (A) from the driver's seat belt tensioner.





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

7. Reconnect the negative cable to the battery.

8. Clear the DTC memory.

9. Read the DTC.

Is DTC 21-1x or 21-2x indicated?

YES -

Go to step 10.

NO -

Open or increased resistance in the driver's seat belt tensioner; replace the driver's seat belt Front Seat Belt Replacement, then clear the DTC.

10. Turn the ignition switch to LOCK (0).

11. Disconnect the negative cable from the battery, then wait at least 3 minutes.

12. Disconnect the front passenger's seat belt tensioner 4P connector.

13. Connect the SRS short cancellers (070AZ-SAA0100) to SRS unit connector B (39P) terminals No. 12 and No. 13.

14. Disconnect SRS unit connector B (39P) from the SRS unit.

15. Measure the resistance between SRS unit connector B (39P) terminals No. 12 and No. 13. There should be 2.0-3.0 Ohms.





Is resistance as specified?

YES -

Faulty SRS unit or poor connection at SRS unit connector B (39P) and the SRS unit. Check the connection; if the connection is OK, replace the SRS unit Service and Repair. If the DTC does not clear, replace the harness.

NO -

Open or increased resistance in the floor wire harness; replace the floor wire harness, then clear the DTC.