SRS System
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 Procedures.
- 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 DTCs with the HDS.
2. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, then wait for 10 seconds.
3. Check for DTCs with the HDS.
Is DTC 21-1x or 21-2x indicated?
YES -
Go to step 4.
NO -
Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. If another DTC is indicated, troubleshoot the DTC.
4. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
5. Disconnect the negative cable from the battery, then wait at least 3 minutes.
6. Remove the left side B-pillar lower trim.
7. Disconnect the driver's seat belt tensioner 4P connector (A) on the floor wire harness.
8. Connect the terminals of SRS simulator lead K to the SRS inflator simulator (2 Ohms connectors), then connect SRS simulator lead K to the driver's seat belt tensioner 4P connector on the floor wire harness.
9. Reconnect the negative cable to the battery.
10. Clear the DTCs with the HDS.
11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, then wait for 10 seconds.
12. Check for DTCs with the HDS.
Is DTC 21-1x or 21-2x indicated?
YES -
Go to step 13.
NO -
Open or increased resistance in the driver's seat belt tensioner; replace the driver's seat belt, then clear the DTC.
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
14. Disconnect the negative cable from the battery, then wait at least 3 minutes.
15. Disconnect SRS unit connector B (39P) from the SRS unit.
16. Connect an SRS short canceller to SRS unit connector B (39P) terminals No. 12 and No. 13.
17. Measure the resistance between SRS unit connector B (39P) terminals No. 12 and No. 13. There should be 2.0-3.0 Ohms.
Is the 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 floor wire harness.
NO -
Open or increased resistance in the floor wire harness; replace the floor wire harness, then clear the DTC.