267 Copyright by Goodheart-Willcox Co., Inc. Technical Terms Chapter 12 Electronic Control Systems air temperature sensor BARO sensor barometric pressure sensor chip clutch apply pressure control loop data link connector dedicated solenoids diagnostic output DLC downshifts drivers duty cycle ECM electronically controlled pressure regulator engine coolant temperature sensor engine speed sensor engine temperature sensor exhaust temperature sensors frequency heated wire inductive sensor input sensors input speed sensor Karmann vortex sensors limp-in mode MAF sensor maintenance indicator light manifold absolute pressure manifold absolute pressure (MAP) sensor manual shift program manual valve position sensor mass airflow sensor microprocessor MIL multi-shift solenoids O2 sensor OBD I OBD II oxygen sensor piezoelectric crystal pressure sensors pulsed ratio control motor resistor temperature sensor scan tool solenoids temperature sensors throttle position sensor (TPS) transducers trouble code turbine speed sensor vane variable ratio control valve variable resistor vehicle speed sensor After studying this chapter, you will be able to: • Explain how electronic controls diff er from hydraulic controls. • Identify input sensors and explain their operation. • Identify output devices and explain their operation. • Describe internal ECM components. • Defi ne control loops and explain their purpose. • Explain how line pressure is controlled by solenoids. • Explain how transmission/transaxle shift s are controlled by solenoids. • Explain the shift sequence of an electronic automatic transmission. • Explain the operation of ECM-operated lockup clutch controls. • Explain the shift sequence of an electronic automatic transaxle. • Explain the operation of a transmission with partial electronic shift controls.