1999 Isuzu Trooper Part TimeFACTORY OEM SERVICE PROCEDURE

Retrieving Codes

NOTE: Diagnostic Trouble Codes (DTCs) are retrieved using Tech 2 or other OBD-II compatible scan tool.
  1. Diagnostic Trouble Code (DTC) retrieval starts with OBD-II diagnostic system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK  . Also see WIRING DIAGRAMS article for circuits and terminals referenced in testing.
  2. Turn ignition on. MIL should come on and remain on steady when ignition is on and engine is not running. When engine is started, MIL should go off. If light remains on while engine is running, a DTC is stored.
  3. If light does not come on with ignition on and engine off, inspect MIL circuit before continuing. If MIL fails to operate, see BASIC DIAGNOSTIC PROCEDURES article.
  4. To retrieve codes, install scan tool. Follow scan tool manufacturer's instruction for DTC retrieval.
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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.

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