Test A: Headlight (Lo Beam, Discharge) Does Not Light Up
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
- Perform the ACTIVE TEST by using the hand-held tester. Connect the hand-held tester to the DLC3. Turn the ignition switch ON and push the hand-held tester main SW ON. Select the item HEAD LIGHT (HI) in the ACTIVE TEST and operate the headlight. If the headlight relay is ON in the tester and the headlight lights up, then check and replace the driver side junction block assembly. If the results are not as specified, go to the next step.
- Inspect the headlight relay continuity. See Fig 2. See INSPECTING HEADLIGHT RELAY CONTINUITY table. If the continuity is OK, go to the next step. If the continuity is not good, replace the headlight relay.INSPECTING HEADLIGHT RELAY CONTINUITY
Condition Tester Connection Specified Condition Constant 1 - 2 Continuity Apply B+ Between Terminal 1 & 2 3 - 5 Continuity - Check the harness and connector between the driver side junction block assembly and headlight relay and light control computer assembly. See Fig 1. Disconnect the connector between the multiplex network body ECU and headlight control computer assembly. Check that the continuity of the vehicle side wiring harness between terminal No. 2F-3 (HRLY) and headlight relay and headlight control computer assembly. If there is continuity, go to the next step. If there is not continuity, repair or replace the harness or connector.
- Replace the discharge headlight bulb with a new one. Check that the light lights up. If the light lights, go to the next step. If the light does not light, replace the discharge headlight bulb.
- Replace the headlight control computer with a new one. Check that the light lights up. If the light lights, go to the next step. If the light does not light, replace the headlight light control computer. See HEADLIGHT ASSEMBLY under REMOVAL & INSTALLATION.
- Read the value of the hand-held tester. Connect the hand-held tester to the DLC3. Turn the ignition switch ON and push the hand-held tester main SW ON. Select the item HEAD LIGHT SW in the DATA LIST and read it's value displayed on the hand-held tester. The results are OK if the light control SW HEAD turns ON and the light control SW except HEAD turns OFF. If the results are OK, check and replace the driver side junction block assembly. If the results are not good, replace the headlight dimmer switch assembly. See HEADLAMP DIMMER/TURN SIGNAL SWITCH ASSEMBLY under REMOVAL & INSTALLATION in STEERING COLUMN SWITCHES - ES 300 article.