Diagnosis & Repair

For wiring diagram, see Fig 1. For diagnosis and repair, see Fig 2-Fig 4 . For ECM location, see Figure. To check for intermittent problems, see INTERMITTENT PROBLEM CHECK  under SELF-DIAGNOSTIC SYSTEM. To identify circuits referenced in testing, See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article. To check ECM inputs and outputs, see PIN VOLTAGE CHARTS article.

Fig 1: DTC P0120 Wiring Diagram

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Fig 2: DTC P0120 Diagnostic Procedure (Steps 1-3)

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Fig 3: DTC P0120 Diagnostic Procedure (Steps 4-5)

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Fig 4: DTC P0120 Diagnostic Procedure (Steps 6-7)

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