Diagnostic Circuit Check

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The Diagnostic Circuit Check is a starting point to identifying a problem caused by the engine control system. The ECM flashes trouble code(s) with the CHECK ENGINE light. Codes start with the lowest code. If no codes were recorded, see TESTS W/O CODES article.

NOTE: TROUBLE SHOOTING and SYMPTOMS are located in TESTS W/O CODES article.

Fig 1: Diagnostic Circuit Check Flow Chart