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Home >> Mitsubishi >> 2003 >> Lancer Evolution >> Repair and Diagnosis >> External Pages >> Different car >> Section 5 (Engine Controls - Self-Diagnostics) >> Self-Diagnostic System >> On-Board Diagnostic II System Check >> Circuit Description
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Circuit Description

WARNING: This page is about a different car, the 2002 Isuzu Trooper. However, it is still accessible from the selected car via links, so may be relevant.

The On-Board Diagnostic II (OBD-II) System Check is the starting point for any driveability complaint diagnosis. The OBD-II system check is an organized approach to identifying problems created by an electronic engine control system malfunction. Before any DTC(s) are retrieved, perform a visual underhood inspection, checking battery and grounds for clean and tight connections. Check for poor connections or damage to wiring harness and electrical connectors. Check for corroded terminals or corrosion buildup on any connection. If problem is found, repair as necessary.