Test No. 17: Illuminated Entry System Does Not Operate

NOTE: When Body Electronic Control Unit (ECU) receives a courtesy signal from either driver's door ECU or passenger's door ECU, the body ECU will turn on the illuminated entry system which consists of room light, ignition lock cylinder light and foot light.

Room light is located on the headliner and may also be referred to as dome light or interior light. See Figure. Check light bulb for each light. Replace light bulb if defective and check light operation. If light bulb is okay, using ohmmeter, check light fixtures for continuity between switch terminals when switch is in ON position. If light fixtures are okay, go to next step. If light fixture is defective, replace component and recheck light operation.
Check wiring harness and electrical connectors between battery and each light, and between each light and Body Electronic Control Unit (ECU). See WIRING DIAGRAMS in ILLUMINATION/INTERIOR LIGHTS article. Body ECU is located 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. If wiring harness and electrical connector are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary and recheck light operation.
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 6.
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 light operation.
Check wiring harness and electrical connectors between door courtesy switch and body ECU. See WIRING DIAGRAMS in ILLUMINATION/INTERIOR LIGHTS 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.
Check door unlock detection switches on all the doors. See DOOR UNLOCK DETECTION SWITCH under COMPONENT TESTS. If door unlock detection switches are okay, go to next step. If any door unlock detection switch is defective, replace door lock assembly and recheck light operation.
Check wiring harness and electrical connectors between each door unlock detection switch and driver's door ECU or passenger's door ECU. See WIRING DIAGRAMS in KEYLESS ENTRY SYSTEMS - AVALON article. Driver's door ECU and passenger's door ECU are located on each door and is incorporated into the power window switch assembly. See Figure. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair wiring harness or electrical connector as necessary and recheck light operation.
Check body ECU for proper voltage and input signals. See BODY ELECTRONIC CONTROL UNIT under PIN VOLTAGE TESTS. If proper voltage and input signals exist, go to next step. If proper voltage or input signal does not exist, repair as necessary and recheck light operation.
Replace body ECU with a known-good body ECU and recheck light operation. If light operates properly, original body ECU was defective. If light still does not operate properly, check wiring harness and electrical connectors for body ECU and interior light for an intermittent problem. Repair wiring harness or electrical connector as necessary.