Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Inspection Procedure
- CHECK LIGHT
- Check that head light and taillight comes on.
NG: FLOW CHART OF HEAD LIGHT OR TAILLIGHT (GO TO PROBLEM SYMPTOMS TABLE )
OK: Go to Next Step.
- Check that head light and taillight comes on.
- READ VALUE OF 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 "AUTO LIGHT SW" in the DATA LIST and read its value displayed on the hand-held tester.
OK:
- Light control SW AUTO --> ON
- Light control SW except AUTO --> OFF
NG: REPLACE HEADLAMP DIMMER SWITCH ASSY
OK: Go to Next Step.
- CHECK AUTOMATIC LIGHT CONTROL SENSOR
- Check the continuity between terminal 3 (+) and body ground as shown in Fig 2 .
- Measure voltage between terminals as shown in Fig 2 .
- Using an oscilloscope, check that signal waveform appears between terminals.
Standard:
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK: FLOW CHART FLOW CHART OF HEAD LIGHT OR TAILLIGHT (GO TO PROBLEM SYMPTOMS TABLE )
NG: Go to Next Step.
- CHECK HARNESS AND CONNECTOR (BETWEEN DRIVER SIDE J/B ASSY AND AUTOMATIC LIGHT CONTROL SENSOR)
- Check that signal waveform appears between terminal B5 - 17 (CLTS) and body ground.
Standard: Bar appears.
OK: CHECK AND REPLACE DRIVER SIDE JUNCTION BLOCK ASSY
NG: Go to Next Step.
- Check that signal waveform appears between terminal B5 - 17 (CLTS) and body ground.
- CHECK HARNESS AND CONNECTOR (BETWEEN DRIVER SIDE J/B ASSY AND AUTOMATIC LIGHT CONTROL SENSOR)
- Measure voltage between terminal B5 - 15 (CLTB) and body ground.
Standard: 10 - 14 V
OK: CHECK AND REPLACE DRIVER SIDE JUNCTION BLOCK ASSY
NG: Go to Next Step.
- Measure voltage between terminal B5 - 15 (CLTB) and body ground.
- CHECK HARNESS AND CONNECTOR (BETWEEN DRIVER SIDE J/B ASSY AND AUTOMATIC LIGHT CONTROL SENSOR)
- Check the continuity between terminal B5 - 16 (CLTE) of driver side J/B assy and 3 (CLTE) of automatic light control sensor.
Standard: There is continuity.
OK: CHECK AND REPLACE DRIVER SIDE JUNCTION BLOCK ASSY
NG: REPLACE AUTOMATIC LIGHT CONTROL SENSOR
- Check the continuity between terminal B5 - 16 (CLTE) of driver side J/B assy and 3 (CLTE) of automatic light control sensor.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.