Hybrid Electric Vehicle Service IAUT 119
Prerequisites: Prerequisites: AUT 109 with a minimum grade of "A".
Studies the operating principles, maintenance, trouble shooting, and service technology of hybrid electric vehicles systems. Includes High-Voltage vehicle safety, operation of hybrid engine, internal combustion engines (ICE), electric motors. Practices service techniques for high voltage inverters, converters and diagnostic systems. Diagnoses and services the high voltage battery, wiring, and climate control systems. Practices boost starting procedures of low voltage battery. Practices disabling and enabling high voltage system for emergency first responder procedures. (25-50)
Outcomes and Objectives
Review high voltage Hybrid Electric Vehicle (HEV) safety.
Diagnose alternating current (AC) Induction and Permanent Magnet Electric Motors.
- Describe the construction of rotors and stators.
- Explain how mutual induction is used to create a magnetic field in a conductor, transformers and motor.
- Describe how AC current flows through the stator coils to produce rotor rotation.
- Compare positive and negative slip rates as related to electric motor torque.
- Diagnose stator conductance valance, insulation and insulation contamination.
- Test the various electric machines using the appropriate diagnostic equipment. Test the electric function of all components of the electric motor as it operates as a motor/generator (MG).
- Diagnose the permanent magnet (PM) brushless motors.
- Explain strategy to overcome torque and speed loss used to assist regenerative braking.
- Verify diagnostic procedure related to regenerative braking and battery charging.
Diagnose Hybrid ICE (Internal Combustion Engine)
- Determine the kind of vehicle ICE engine in sample vehicles.
- Compare Otto, Atkinson and combination Atkinson/Miller-cycle engines as well as light Diesel Engines.
- Describe how an Otto-cycle engine compares to an Atkinson-cycle engine at low, medium and high load ranges.
- Describe the advantages of combining an Atkinson-cycle engine with an electric traction system.
- Perform a compression test on an ICE engine in a hybrid vehicle.
Diagnose Power Inverters, Converters, and Electric Propulsion Sensing Systems.
- Identify power inverters location.
- Identify types of transistors used in power inverter.
- Describe current sensors applications for power inverters.
- Describe how sine waveforms are created.
- Verify sine wave conversion from direct current (DC) source using Oscilloscope.
- Demonstrate how to calculate rotor frequency and motor speed.
- Describe the operation of a DC brush type motor.
- Explain how power inverter boost is created.
- Describe the operation of the pack motor drive system.
- Verify regenerative braking system is working.
- Diagnose several styles of speed sensors, resolvers, encoders and proximity sensors.
- Diagnose throttle position sensors using scan tool and voltmeter.
- Identify other vehicle sensors that relate to electric propulsion system.
- Describe the functions, location and diagnosis of the AC to DC converter.
Diagnose and verify operation of Electric Transaxle and Cooling Systems
- Describe the components of the Toyota Prius EVT (Electronically Variable Transmission).
- Explain the roles of the Motor Generators (MG1 and MG2).
- Describe how the Prius transmission controls the infinite gear ratio.
- Identify and describe the construction of electronics and an electric motor cooling system.
- Perform Cooling System Service in a Prius.
Diagnose and repair Energy Management Hardware Systems
- Diagnose and replace high-voltage fuse following manufacturer’s instructions.
- Verify condition of wires, cables, and shielding.
- Describe operation and service of the pre-charge circuit.
- Perform test of pre-charged circuit.
- Describe operation and service procedures of battery-pack contactor system.
- Perform test of the battery pack contactor system.
- Describe the difference between active and passive thermal systems.
- Describe the operation and test procedures of terminal voltage sensing circuits.
Perform service procedures of flooded lead acid, AGM Deep Cycle Batteries and all high-voltage batteries.
- Diagnose State Of Charge, State Of Health, Energy Content of each battery: Flooded lead Acid, AGM, Deep Cycle, and High Voltage.
- Describe chemical processes to produce electricity, electrolyte analysis and battery inspection procedures.
- Complete service procedures to discharge and charge batteries.
- Define and calculate capacity rate and Amp-Hour energy content.
- Calculate electrical power on parallel and series battery configuration.
- Define energy density and power density.
- Diagnose specific energy and specific power content.
- Perform high-voltage battery discharge, charge and balance using computerized battery discharging and charging equipment.
Service Procedures of Hybrid Regenerative Braking Systems
- Describe how regenerative and hydraulic braking systems interact with battery pack State of Charge.
- Describe the different categories of braking system operation.
- Identify foundation brakes/ABS/TCS and hill-hold control function vs. creep-aid systems.
Service Hybrid High-Voltage Climate Control Systems
- Service of high voltage air conditioning (A/C) compressor and Heating, Ventilation, Air-Conditioning systems.
- Service heating coolant pumps and heat storage system.
- Diagnose high voltage A/C power inverter.
- Test Amp/Hz of A/C compressor using inductive clamp method.
- Describe other A/C compressors; combination electric-belt driven.