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Home >> GMC >> 1990 >> Forward Control 4.3 Z, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> Theory and Operation >> Engine Controls - Theory & Operation >> Input Devices >> Notes

Input Devices: Notes

Each sensor or switch furnishes electronic (voltage) signals to ECM. The ECM uses these input signals to compute ignition timing, air/fuel ratio and idle speed for proper driveability and emission control. Various models are equipped with different combinations of input devices. Not all devices are used on all models. To determine the input usage, see appropriate wiring diagram in WIRING DIAGRAMS article. The available input signals include the following: