Diagnostic Procedure
WARNING: This page is about a different car, the 2003 Lexus IS 300 and 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If not using the hand-held tester, start the inspection from step 2.
- Connect the hand-held tester to the DLC3 and turn the ignition and hand-held tester switch ON. See Fig 1. Check the back door courtesy switch using DATA LIST. If the results are OK, the circuit is OK. Further diagnosis is needed. If the results are not OK, go to the next step.
- Check the back door courtesy switch. See DOOR COURTESY SWITCH (BACK) under COMPONENT TESTS under AUTOMATIC HEADLIGHTS & LIGHTING SYSTEMS article under HEADLIGHTS in ACCESSORIES & EQUIPMENT. If the results are OK, go to the next step. If the results are not OK, replace the back door courtesy switch.
- Check the wiring harness and connector between the back door courtesy switch and body ECU. See WIRING DIAGRAMS . If the results are OK, the circuit is OK. Further diagnosis is needed. If the results are not OK, repair or replace the wiring harness or connector.