FixVault

Fog Light System:

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
FOG LIGHT SYSTEM

Symptom Suspect Area See Section
Fog light does not light up or has abnormal operation.
  1. Front fog light circuit
  2. Light control switch circuit
  3. Combination switch
  4. Front light ECU
  5. Driver side J/B ECU
  1. FRONT FOG LIGHT CIRCUIT
  2. LIGHT CONTROL SWITCH CIRCUIT 
  3. HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE
  4. HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE
  5. HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE