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Code 12

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 12 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. Disconnect center air bag sensor connector. Reconnect negative battery cable. Measure voltage between body ground and each terminal of spiral cable upper connector (spiral cable side of connector). If zero volts is present, go to next step. If any voltage is present, go to step 17).
  3. Measure voltage between body ground and positive (+) terminal of passenger-side air bag connector (harness side). See Figure. If zero volts is present, go to next step. If any voltage is present, replace harness between center air bag sensor and passenger-side air bag.
  4. Remove cover from seat belt pretensioner check connector located under right rear seat. See Figure. Measure voltage between body ground and terminals No. 3 and 7 of seat belt pretensioner check connector. If no voltage is present, go to next step. If any voltage is present, replace harness between seat belt pretensioner check connector and seat belt pretensioner.
  5. Measure voltage between body ground and terminals No. 4 and 8 of seat belt pretensioner check connector. If no voltage is present, go to next step. If any voltage is present, replace harness between seat belt pretensioner check connector and center air bag sensor.
  6. Turn ignition switch to LOCK position. Disconnect negative battery cable. Reconnect center air bag sensor connector. Securely install cover onto seat belt pretensioner check connector. Connect jumper wires between terminals of spiral cable upper connector, passenger-side air bag connector and both seat belt pretensioner connectors (harness side of each connector).
  7. Reconnect negative battery cable. Wait at least 20 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. Turn ignition switch to ACC or ON position. Wait at least 20 seconds.
  8. Connect jumper wire between terminals Tc and E1 of DLC. See Figure. If Code 12 is not displayed, go to next step. If Code 12 is displayed, replace center air bag sensor.
  9. Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait at least 90 seconds. Connect spiral cable upper connector (steering wheel pad). 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.
  10. 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 12 is not displayed, go to next step. If Code 12 is displayed, replace steering wheel pad.
  11. Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait at least 90 seconds. Connect passenger-side air bag 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.
  12. 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 12 is not displayed, go to next step. If Code 12 is displayed, replace passenger-side air bag.
  13. Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait at least 90 seconds. Connect left seat belt pretensioner connector. Securely install cover onto seat belt pretensioner check connector. Connect center air bag sensor 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.
  14. 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 12 is not displayed, go to next step. If Code 12 is displayed, replace left seat belt pretensioner.
  15. 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.
  16. 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 12 is not displayed, go to next step. If Code 12 is displayed, replace right seat belt pretensioner.
  17. Turn ignition switch to LOCK position. Disconnect spiral cable lower connector. Turn ignition switch to ON position. Measure voltage between body ground and positive (+) terminal of spiral cable upper connector (spiral cable side). See Figure. If no voltage is present, replace harness between center air bag sensor and spiral cable. If any voltage is present, replace spiral cable.
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