Headlight Signal Circuit
The headlight leveling ECU assembly detects the low beam headlights status.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
First check that the low beam headlights operate normally.
PROCEDURECHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - ECU)
(a) Disconnect the A40 headlight leveling ECU assembly connector. |
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(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
A40-3 (B2) - Body ground |
Light control switch in head position |
11 to 14 V |
*1 |
Front view of wire harness connector (to Headlight Leveling ECU assembly) |
| OK | ![]() | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| NG | ![]() | REPAIR OR REPLACE HARNESS OR CONNECTOR |
Test yourself
A quick Toyota Venza quiz: every answer comes with an explanation and a link to the manual page.

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