Engine Controls - Tests W/Codes - V6: Introduction

1990 Toyota 4Runner 2D Utility, 3.0 V, AutomaticSECTION Introduction

If no faults were found while performing BASIC TESTING - V6 article, proceed with TESTS W/CODES - V6 article. If no trouble codes or only pass codes are present, proceed to TESTS W/O CODES - EFI article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).

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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.