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Engine Control Module

Engine Control Module (ECM) monitors and controls vehicle emissions, fuel system, ignition system and other various systems by using input signals from various input devices. ECM processes input signals from input devices and delivers output signals to various components for controlling system operation to achieve optimum engine performance for all operating conditions. See INPUT DEVICES and OUTPUT SIGNALS . ECM contains a fail-safe function which is used in case of sensor or switch failure. Fail-safe function uses preprogrammed values to provide a limp-in mode for minimal driveability. If a failure exists, ECM will inform the driver by illuminating the MIL.

NOTE: MIL may also be referred to as CHECK ENGINE light. MIL is displayed as an engine icon on instrument cluster on instrument panel.

ECM contains a self-diagnostic system which may store a DTC if an electronic control system failure exists. DTC may be retrieved from ECM for system diagnosis by using a scan tool. See SELF-DIAGNOSTIC SYSTEMS . For ECM location, see Fig 1-Fig 15 .

Fig 1: Locating Engine Control Module (Avalon)

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Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Locating Typical Engine Control Module (Camry 2.2L 4-Cyl. CNG & Gasoline Models, & Camry Solara 2.2L 4-Cyl.)

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Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 3: Locating Typical Engine Control Module (Camry 3.0L V6 & Camry Solara 3.0L V6)

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Fig 4: Locating Engine Control Module (Celica)

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Fig 5: Locating Engine Control Module (Corolla)

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Fig 6: Locating Engine Control Module (ECHO)

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Fig 7: Locating Engine Control Module (Highlander)

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Fig 8: Locating Engine Control Module (Land Cruiser)

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Fig 9: Locating Engine Control Module (MR2)

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Fig 10: Locating Engine Control Module (Prius)

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Fig 11: Locating Engine Control Module (RAV4)

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Fig 12: Locating Engine Control Module (Sequoia & Tundra)

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Fig 13: Locating Engine Control Module (Sienna)

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Fig 14: Locating Engine Control Module (Tacoma 2.4L 4-Cyl. & 2.7L 4-Cyl., & 4Runner)

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Fig 15: Locating Engine Control Module (Tacoma 3.4L V6)

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Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002