DTC 21-91

DTC 21-91: Short to Ground in Driver's Seat Belt Tensioner

Special Tools Required
- SRS inflator simulator 07SAZ-TB4011A
- SRS simulator lead K 070AZ-SNAA200

1. Erase the DTC memory.
2. 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 21-91 indicated?

YES - Go to step 3.

NO - Intermittent failure, system is OK at this time. Go to Troubleshooting Intermittent Failures. Troubleshooting Intermittent Failures If another DTC is indicated, go to the DTC Troubleshooting Index. Diagnostic Trouble Code Descriptions

3. Turn the ignition switch OFF. Disconnect the negative cable from the battery, and wait for 3 minutes.




4. Disconnect the SRS 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 SRS wire harness.
6. Reconnect the negative cable to the battery.
7. Erase the DTC memory.
8. Read the DTC.

Is DTC 21-91 indicated?

YES - Go to step 9.

NO - Short to ground in the driver's seat belt tensioner; replace the driver's seat belt.

9. Turn the ignition switch OFF. Disconnect the negative cable from the battery, and wait for 3 minutes.
10. Disconnect both seat belt buckle tensioner 4P connectors and the front passenger's seat belt tensioner 4P connector.
11. Disconnect SRS unit connector B (28P) from the SRS unit.
12. Disconnect the simulator lead from the SRS wire harness.




13. 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 Mohm.

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 SRS wire harness; replace the SRS wire harness.