Engine Control Module (ECM)

NOTE: Components are grouped into 2 categories. First category is INPUT DEVICES , which are components that control or produce signals monitored by ECM. Second category is OUTPUT SIGNALS , which are components controlled by ECM.

The on-board diagnostics (OBD-II) system detects and indicates a fault in various input and output components of the complex electronic control system. The Check Engine malfunction indicator lamp (MIL) in the combination meter indicates occurrence of a fault or trouble code. Further, against a sensor failure that may disable driveability, the fail-safe function is provided to ensure the minimal driveability. The OBD-II system incorporated with the vehicles within this engine family complies with Section 1968.1, California Code of Regulations (OBD-II regulation). When the system decides that a malfunction occurs, MIL illuminates. At the same time of the MIL illumination or blinking, a diagnostic trouble code (DTC) and freeze frame engine conditions are stored into the on-board computer. The OBD-II system stores freeze frame engine condition data (engine load, engine coolant temperature, fuel trim, engine speed and vehicle speed, etc.) into an on-board computer when it detects a malfunction. If the OBD-II system detects the various malfunctions including the fault of fuel trim or misfire, the OBD-II system first stores freeze frame engine conditions about the fuel trim or misfire. When the malfunction does not occur again for three consecutive driving cycles, MIL is turned "OFF", but DTC remains in the on-board computer. The OBD-II system is capable of communication with a general scan tool (OBD-II general scan tool) formed by ISO 9141 CARB. For further self-diagnostic system information, see appropriate SELF-DIAGNOSTICS article. ECM is located under right side of dash, behind glove box.