Engine Control Module Power Source Circuit: 4Runner
For engine control module power source circuit inspection, see Fig 1-Fig 7 . For circuit identification, see ENGINE PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Before replacing ECM, check ECM connectors and ground circuits. See ENGINE CONTROL MODULE POWER & GROUND CIRCUITS under COMPUTERIZED ENGINE CONTROLS. To check EFI main relay, see EFI MAIN RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS.