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Test No. 1: Theft Deterrent System Cannot Be Set

WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn ignition off. Remove instrument cluster. See REMOVAL & INSTALLATION under INSTRUMENT PANELS - AVALON article in ACCESSORIES & EQUIPMENT. Disconnect instrument cluster 22-pin electrical harness connector C9. Using fused jumper wires, connect positive battery voltage to terminal No. 22 and negative battery voltage to terminal No. 21 of instrument cluster. If SECURITY indicator light comes on, go to next step. If SECURITY indicator light does not come on, replace instrument cluster. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  2. Remove jumper wires. Disconnect instrument cluster 22-pin electrical harness connector C9. Disconnect theft deterrent ECU 26-pin electrical harness connector T4. Using DVOM, check Violet/White wire between instrument cluster 22-pin electrical harness connector C9 terminal No. 22 and theft deterrent ECU 26-pin electrical harness connector T4 terminal No. 12. See Figure. Also check White/Black wire between instrument cluster 22-pin electrical harness connector C9 terminal No. 21 and body ground point located on cowl under left side of instrument panel. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. If wiring harnesses and electrical connectors are okay, go to next step. If wiring harnesses or electrical connectors are defective, repair as necessary. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  3. If problem is because theft deterrent system will not set, go to next step. If problem is not because theft deterrent system will not set, check theft deterrent ECU ground circuits. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. If ground circuits are faulty, repair and retest system. If ground circuits are okay, substitute original theft deterrent ECU with a known-good unit and recheck system operation. If system operates properly, original theft deterrent ECU was defective. If system still does not operate properly, perform theft deterrent ECU pin voltage/resistance checks. See Figure. If voltage/resistance values are okay, replace theft deterrent ECU. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  4. Remove DOOR NO. 1 (25-amp) and ECU-B (7.5-amp) fuses from driver side junction block. See Figure. If both fuses are okay, go to next step. If either fuse is blown, locate and repair short circuit in affected wiring. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  5. Reinstall fuses. Disconnect theft deterrent ECU 26-pin electrical harness connector T4. Using DVOM with negative probe at theft deterrent ECU 26-pin electrical harness connector T4 terminal No. 11 (White/Black wire), measure voltage at theft deterrent ECU 26-pin electrical harness connector T4 terminals No. 1 (Blue/Red wire) and No. 2 (White/Green wire) with positive lead. See Figure. If voltage is 10-14 volts, go to step  7. If voltage is not 10-14 volts, go to next step.
  6. Check ground circuit (White/Black wire) between theft deterrent ECU 26-pin electrical harness connector T4 terminal No. 11 and vehicle ground points. One vehicle ground point is located behind right side of instrument panel and the other is located on right front side of engine compartment, on inner fender panel to right of fuse block. Also check power feed circuits (Blue/Red and White/Green wires) between theft deterrent ECU 26-pin electrical harness connector T4 terminals No. 1 and 2 and battery. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. Repair as necessary.
  7. Locate and disconnect key unlock warning switch 2-pin electrical harness connector. See Figure. Using DVOM, check for continuity across switch terminals. With key in ignition, continuity should exist. With key removed from ignition, continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, replace key unlock warning switch. See appropriate POWER DOOR LOCK ASSEMBLY under REMOVAL & INSTALLATION article under POWER DOOR LOCKS WITHOUT KEYLESS ENTRY - AVALON article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.
  8. Disconnect theft deterrent ECU 26-pin electrical harness connector T4 and key unlock warning switch 2-pin electrical harness connector. Check Red/Yellow wire between theft deterrent ECU 26-pin electrical harness connector T4 terminal No. 4 and key unlock warning switch 2-pin electrical harness connector terminal No. 2. Also check ground circuit (White/Black wire) between unlock warning switch 2-pin electrical harness connector terminal No. 1 and body ground point located on cowl under left side of instrument panel. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. If wiring harnesses and electrical connectors are okay, go to next step. If wiring harnesses or electrical connectors are defective, repair as necessary. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  9. If problem is because theft deterrent system will not set, go to next step. If problem is not because theft deterrent system will not set, check theft deterrent ECU ground circuits. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. If ground circuits are faulty, repair and retest system. If ground circuits are okay, substitute original theft deterrent ECU with a known-good unit and recheck system operation. If system operates properly, original theft deterrent ECU was defective. If system still does not operate properly, perform theft deterrent ECU pin voltage/resistance checks. See Figure. If voltage/resistance values are okay, replace theft deterrent ECU. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  10. Remove luggage compartment door (trunk lid) trim panel. Locate luggage compartment door lock and unlock switch. See Figure. Turn ignition on. Using a DVOM, connect negative lead to good body ground point and backprobe luggage compartment door lock and unlock switch connector terminal No. 1 (White/Black wire) with positive lead. When luggage compartment door lock is turned to UNLOCK position, battery voltage should exist. When luggage compartment door lock is not turned to UNLOCK position, zero volts should exist. If voltage readings are okay, go to step  13. If voltage readings are not okay, go to next step.
  11. Turn ignition off. Disconnect luggage compartment door lock and unlock switch 2-pin electrical harness connector. Using a DVOM, check continuity across luggage compartment door lock and unlock switch terminals. When luggage compartment door lock is turned to UNLOCK position, continuity should exist. When luggage compartment door lock is not turned to UNLOCK position, continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, replace luggage compartment lock and unlock switch. See REMOVAL & INSTALLATION in POWER TRUNK LID - AVALON article under POWER DOOR LOCKS WITHOUT KEYLESS ENTRY - AVALON article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  12. Disconnect theft deterrent ECU 26-pin electrical harness connector T4 and luggage compartment door lock and unlock switch 2-pin electrical harness connector. Check Green/White wire between theft deterrent ECU 26-pin electrical harness connector T4 terminal No. 3 and luggage compartment door lock and unlock switch 2-pin electrical harness connector terminal No. 2. Also check ground circuit (White/Black wire) between luggage compartment door lock and unlock switch 2-pin electrical harness connector terminal No. 1 and body ground point located at right front corner of luggage compartment. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. If wiring harnesses and electrical connectors are okay, go to next step. If wiring harnesses or electrical connectors are defective, repair as necessary. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  13. If problem is because theft deterrent system will not set, go to next step. If problem is not because theft deterrent system will not set, check theft deterrent ECU ground circuits. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. If ground circuits are faulty, repair and retest system. If ground circuits are okay, substitute original theft deterrent ECU with a known-good unit and recheck system operation. If system operates properly, original theft deterrent ECU was defective. If system still does not operate properly, perform theft deterrent ECU pin voltage/resistance checks. See Figure. If voltage/resistance values are okay, replace theft deterrent ECU. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  14. Turn ignition off. Open hood and remove hood latch assembly to access hood courtesy switch. Disconnect hood courtesy switch 2-pin electrical harness connector. Using DVOM, check continuity across hood courtesy switch terminals. When hood latch assembly is in UNLOCK position, continuity should exist. When hood latch assembly is in LOCK position, continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, replace hood courtesy switch. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  15. Disconnect theft deterrent ECU 26-pin electrical harness connector T4 and hood courtesy switch 2-pin electrical harness connector. Check Black wire between theft deterrent ECU 26-pin electrical harness connector T4 terminal No. 6 and hood courtesy switch 2-pin electrical harness connector terminal No. 1. Also check ground circuit (White/Black wire) between hood courtesy switch 2-pin electrical harness connector terminal No. 2 and body ground point located at left side of engine compartment on inner fender panel to right of engine compartment junction block. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. If wiring harnesses and electrical connectors are okay, go to next step. If wiring harnesses or electrical connectors are defective, repair as necessary. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
  16. Check theft deterrent ECU ground circuits. See ANTI-THEFT in SYSTEM WIRING DIAGRAMS article. If ground circuits are faulty, repair and retest system. If ground circuits are okay, substitute original theft deterrent ECU with a known-good unit and recheck system operation. If system operates properly, original theft deterrent ECU was defective. If system still does not operate properly, perform theft deterrent ECU pin voltage/resistance checks. See Figure. If voltage/resistance values are okay, replace theft deterrent ECU. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
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