Diagnosis & Repair
For wiring diagram of Corolla model, see Fig 1. For wiring diagram of Matrix (1ZZ-FE engine) model, see Fig 2. For wiring diagram of Matrix (2ZZ-GE engine) model, see Fig 3. For diagnosis and repair, see Fig 4-Fig 6 . For ECM location, see Figure. To go relevant DTC chart, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . For vacuum hose routing, see VACUUM DIAGRAMS article. 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. For testing of systems or components, see BASIC DIAGNOSTIC PROCEDURES - 4-CYL article or SYSTEM & COMPONENT TESTING - 4-CYLINDER article. To check for intermittent problems, see INTERMITTENT PROBLEM CHECK under SELF-DIAGNOSTIC SYSTEM. To check ECM inputs and outputs, see PIN VOLTAGE CHARTS article.