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Home >> Lexus >> 2002 >> SC 430 >> Repair and Diagnosis >> External Pages >> Different car >> Section 62 (Body Control Systems) >> Circuit Tests >> Headlight Relay Circuit >> Circuit Description
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Circuit Description

WARNING: This page is about a different car, the 2003 Lexus GS 430, 2003 Lexus GS 300, 2002 Lexus GS 430, and 2002 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

The headlight relay will be ON by operating the headlight switch. The transistor which activates the taillight relay has 2 types:

  1. One activates directly by the headlight switch for fail safe operation.
  2. Another activates by the body ECU No. 2.
The one that activates by body ECU No. 2 has 2 systems and prevents the headlight from turning off at the time of one system trouble in the automatic operation circuit.

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