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Code 73

WARNING: This page is about a different car, the 1994 Lexus LS 400. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: During testing, if codes other than Code 73 are displayed, disregard them.
  1. Disconnect negative battery cable. Wait at least 90 seconds. Remove steering wheel pad. See STEERING WHEEL PAD & SPIRAL CABLE  under REMOVAL & INSTALLATION. Disconnect passenger-side air bag harness connector, accessible through finish plate in glove box. See Figure. Disconnect seat belt pretensioner connectors.
  2. Measure resistance between terminals of right seat belt pretensioner connector (harness side). If resistance is less than 1000 ohms, go to step 7). If resistance is 1000 ohms or more, connect jumper wire between terminals of spiral cable upper connector, passenger-side air bag connector and both seat belt pretensioner connectors (harness side of each connector).
  3. Reconnect negative battery cable. Wait at least 2 seconds. Turn ignition switch to LOCK position. Wait at least 2 seconds. Turn ignition switch to ACC or ON position. Wait at least 20 seconds. Clear codes. See CLEARING CODES  under SELF-DIAGNOSTIC SYSTEM. Turn ignition switch to LOCK position. Wait at least 20 seconds.
  4. Disconnect jumper wire from right seat belt pretensioner connector. Turn ignition switch to ACC or ON position. Wait at least 20 seconds. Connect jumper wire between terminals Tc and E1 of DLC. See Figure. If Code 73 is not displayed, go to next step. If Code 73 is displayed, replace center air bag sensor.
  5. Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait at least 90 seconds. Connect right seat belt pretensioner connector. Reconnect negative battery cable. Wait at least 2 seconds. Turn ignition switch to ACC or ON position. Wait at least 20 seconds. Clear codes. See CLEARING CODES  under SELF-DIAGNOSTIC SYSTEM.
  6. Turn ignition switch to LOCK position. Wait at least 20 seconds. Turn ignition switch to ACC or ON position. Wait at least 20 seconds. Connect jumper wire between terminals Tc and E1 of DLC. See Figure. If Code 73 is displayed, replace right seat belt pretensioner. If Code 73 is not displayed, check for intermittent fault. See AIR BAG WARNING LIGHT INTERMITTENT  under DIAGNOSIS & TESTING.
  7. Pull out seat belt pretensioner check connector from under right rear seat. See Figure. Remove cover from seat belt pretensioner check connector. Release both shorting bar springs on seat belt pretensioner check connector. See RELEASING SHORTING BAR SPRING  under DIAGNOSIS & TESTING.
  8. Measure resistance between terminals No. 2 and 3 of seat belt pretensioner check connector. If resistance is infinite, go to next step. If resistance is not infinite, replace harness between right seat belt pretensioner and seat belt pretensioner check connector.
  9. Disconnect center air bag sensor connector. Release shorting bar spring (air bag activation prevention mechanism) built into center air bag sensor connector. See RELEASING SHORTING BAR SPRING  under DIAGNOSIS & TESTING.
  10. Measure resistance between terminals No. 1 and 4 of seat belt pretensioner check connector. If resistance is infinite, go to next step. If resistance is not infinite, replace harness between center air bag sensor and seat belt pretensioner check connector.
  11. Connect center air bag sensor connector. Measure resistance between terminals No. 1 and 4 of seat belt pretensioner check connector. If resistance is less than 1000 ohms, replace center air bag sensor. If resistance is 1000 ohms or more, check for intermittent fault. See AIR BAG WARNING LIGHT INTERMITTENT  under DIAGNOSIS & TESTING.
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