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Test No. 2: Key Unlock Warning System Buzzer Inoperative

NOTE: Test should be performed if key unlock warning system buzzer does not sound when driver's door is opened with ignition off and ignition key in ignition lock cylinder.
  1. Power source for Body Electronic Control Unit (ECU) should be checked. Check the following fuses: ECU-ACC (5-amp), DOOR No. 1 (25-amp), ECU-IG No. 2 (10-amp) and ECU-B (7.5-amp). These fuses are located in the fuse/relay box at driver's side of instrument panel. See Figure. Also, check DOOR No. 2 fuse (15-amp). DOOR No. 2 fuse is located in fuse/relay box at driver's side front corner of engine compartment. See Figure. If all fuses are okay, go to next step. If any fuse is defective, replace fuse and repair wiring harness or electrical connector on wiring circuit as necessary. See WIRING DIAGRAMS .
  2. Note location of body ECU at driver's side of instrument panel on the fuse/relay box. See Figure. Electrical connector B4 (25-pin) and electrical connector B5 (25-pin) are located at each side of body ECU and a 12-pin electrical connector at rear of body ECU. See Figure.
  3. Turn ignition on. Using voltmeter, check voltage between ground circuit at terminal No. 14 (White/Black wire: GND1 terminal) at electrical connector B5 and terminals No. 1 (BDR1 terminal), No. 2 (SIG terminal) and No. 3 (ACC terminal) at the 12-pin electrical connector. See Figure. Also, check voltage between ground circuit at terminal No. 11 (White/Black wire: GND2 terminal) at electrical connector B4 and terminals No. 1 (BDR1 terminal), No. 2 (SIG terminal) and No. 3 (ACC terminal) at the 12-pin electrical connector. See Figure. Voltage should be 10-14 volts. Go to next step.
  4. Turn ignition off. Disconnect electrical connectors at body ECU. Using voltmeter, check voltage between ground circuit at terminal No. 14 (White/Black wire: GND1 terminal) at electrical connector B5 and terminal No. 24 (White/Green wire; "B" terminal) at electrical connector B4 and terminal No. 7 (BDR2 terminal) at the 12-pin electrical connector. See Figure. Also, check voltage between ground circuit at terminal No. 11 (White/Black wire: GND2 terminal) at electrical connector B4 and terminal No. 24 (White/Green wire; "B" terminal) at electrical connector B4 and terminal No. 7 (BDR2 terminal) at the 12-pin electrical connector. See Figure. Voltage should be 10-14 volts. Go to next step.
  5. If all voltage readings are within specification, reinstall electrical connectors and go to step  7. If any voltage is not within specification, check for open in wiring harness and electrical connectors between ground connections and terminal No. 11 at electrical connector B4 and terminal No. 14 at electrical connector B5. See WIRING DIAGRAMS . If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary and recheck system operation.
  6. Check wiring harness and electrical connectors between battery, ignition switch and body ECU. See WIRING DIAGRAMS . For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS. Repair wiring harness or electrical connector as necessary and recheck system operation.
  7. Check key unlock warning switch. See KEY UNLOCK WARNING SWITCH  under COMPONENT TESTS. If key unlock warning switch is okay, go to next step. If key unlock warning switch is defective, replace key unlock warning switch and recheck system operation. See KEY UNLOCK WARNING SWITCH  under REMOVAL & INSTALLATION.
  8. Check key unlock warning switch circuit by checking Red/Yellow wire and electrical connectors between terminal No. 2 at key unlock warning switch and terminal No. 17 at electrical connector B4 at body ECU. For electrical connector B4 location and terminal identification, see Figure. See WIRING DIAGRAMS in KEYLESS ENTRY SYSTEMS - AVALON article. Key unlock warning switch may also be referred to as unlock switch. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary and recheck system operation.
  9. Open each door and check that door courtesy light comes on when door is opened and goes off when door is closed. If any door courtesy light does not operate properly when door is open and closed, go to next step. If door courtesy light operates properly when each door is open and closed, go to step  12.
  10. Check door courtesy switch. See DOOR COURTESY SWITCH  under COMPONENT TESTS. If door courtesy switch is okay, go to next step. If door courtesy switch is defective, replace door courtesy switch and recheck system operation.
  11. Check wiring harness and electrical connectors between door courtesy switch and body ECU. See WIRING DIAGRAMS in KEYLESS ENTRY SYSTEMS - AVALON article. For door courtesy lights on driver's side front door and passenger's side front door, it may be necessary to check wiring between door courtesy light and driver's door ECU or passenger's door ECU. For additional wiring for interior lighting, see WIRING DIAGRAMS in ILLUMINATION/INTERIOR LIGHTS article.
  12. Check driver door control system for trouble symptoms. See TROUBLE SHOOTING PROCEDURE (DRIVER DOOR CONTROL SYSTEM)  under TROUBLE SHOOTING. If no trouble symptoms exist, go to next step.
  13. Replace body ECU with a known-good body ECU and recheck system operation. If system operates properly, original body ECU was defective. If system still does not operate properly, check wiring harness and electrical connectors for body ECU and key unlock warning switch for an intermittent problem. Repair wiring harness or electrical connector as necessary.
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