Hybrid and Alternative Fuel Vehicles By James D

OBJECTIVES After studying Chapter 14, the reader should be able to: 1. Identify General Motors parallel hybrid trucks, Saturn VUE hybrid, and two-mode hybrid systems. 2. Describe how the parallel hybrid truck system works. 3. Describe the features and operating characteristics of the General Motors parallel trucks, VUE, and two-mode hybrid vehicles. 4. Explain the precautions necessary when working on General Motors hybrid vehicles. 5. Explain the service procedures for General Motors hybrid vehicles. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

CHEVROLET/GMC PARALLEL HYBRID TRUCK The overall goal of the parallel hybrid truck (PHT) was to maximize fuel economy on vehicles with relativity high-base fuel consumption and high-potential sales volume. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Starter Alternator The pickup trucks have what General Motors calls a flywheel alternator starter (FAS) system hybrid. The electric machine was designed as two assemblies: A rotor assembly A stator assembly Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

The rotor assembly consisted of an electric rotor assembled onto a rotor hub that bolted to the engine crankshaft and wrapped around the torque converter. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Instead of a conventional starter motor and alternator, the hybrid truck uses the electric motor for starting power and is capable of generating up to 14, 000 watts of continuous electric power. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Batteries Three valve-regulated lead acid (VRLA) batteries are used in the GM parallel hybrid truck to provide a 36 -volt nominal voltage and a charging voltage of 42. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Still retaining the vehicle 14 -volt battery, a dual 42 -volt vehicle electrical system minimizes component changes. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Idle Stop When the truck is decelerating, it enters a mode called Deceleration Fuel Cut-Off (DFCO). A DFCO transition or ramping delay of only 1 to 2 seconds for each event helps to improve fuel economy. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Auxiliary Power Outlet (APO) System The Auxiliary Power Outlet (APO) system provides up to 2, 400 watts of 120 -volt AC power. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

The four (two duplex outlets) 120 -volt, 20 -amp electrical auxiliary power outlets can provide power to electric saws, grinders, or laptops. There are outlets located inside the cabin and in the truck bed. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

The 110 -volt outlet in the rear seat area of the Chevrolet hybrid truck makes it convenient to use a laptop computer because the power available at the outlet does not require the use of an inverter that is needed in other vehicles that do not have 100 volts AC. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Short Circuits, Overloads, and Ground-Fault Detection (GFD) The 120 -volt AC power outlets are protected against short circuits, overloads, and ground faults. The APO system will operate in the continuous mode with the engine running until one of the following occurs: The APO button is depressed. The fuel level gets low. Engine oil pressure becomes too low. Engine coolant temperature becomes too hot. The ignition key is moved out of the LOCK position. The hybrid power system becomes too hot. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Resetting the Short Circuit, Overload, or Ground-Fault Detection (GFD) Circuit To reset the short circuit, overload or ground-fault detection (GFD) circuit while operating in both the normal and continuous modes, ensure that any observed fault is removed, and press the APO button. The light next to the button will illuminate indicating that the system is supplying 120 -volt AC power to the outlets. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Electric-Hydraulic Power Steering A 42 -volt electric-hydraulic power steering (EHPS) pump replaced the traditional beltdriven unit. The EHPS module controls the EHPS power pack, which is an integrated assembly consisting of the following components: Electric motor Hydraulic pump Fluid reservoir Reservoir cap Fluid level sensor Electronic controller Electrical connectors Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

EHPS Module The EHPS module is operated from the 36 -volt (nominal) power supply. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Electric Machine (EM) Cooling Coolant for the electric machine (electric motor) is taken from the engine water jacket, and is routed around the stator through a water channel created by the two stampings used as a carrier for the stator, and returned to the suction side of the engine coolant system. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Driving the GM Parallel Hybrid Truck On the road, the Sierra/Silverado hybrids drive like any other V-8 -powered GM pickup. On a grade, the truck will roll backward in the time it takes between depressing the brake, and automatically restarting the engine. This can be avoided by pressing a button at the end of the column-mounted gear shift, which prevents the engine from shutting down. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Automatic Engine Start/Stop Override The engine will stay running at a complete stop or will automatically start from a complete stop if: The outside temperature is high -- usually above 95°F (35°C). The climate control system is working to cool the cabin in AUTO mode. The climate control system is in front defrost mode. The brake pedal is released in Drive (D) or Third (3). The shift lever is in Neutral, Reverse (R), Second (2) or First (1). The battery pack charge is low. The tow/haul mode is active. The transfer case is in the 4 LO position. Any door is opened while the vehicle is in Park (P). It is necessary to maintain 120 -volt APO operation for loads greater than 1 kilowatt. The hood is not fully closed. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Manual Override System To manually override the automatic engine start/stop system, press the tow/haul switch located on the end of the column shift lever. When the tow/haul mode has been activated, this light will come on in the instrument cluster. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Service and Testing BPP Calibration. On the Chevrolet hybrid truck, the brake pedal position (BPP) sensor receives a low reference signal and a 5 -volt reference signal from the electro-hydraulic power steering (EHPS). Whenever the brake pedal is applied, the brake pedal position sensor applies a variable voltage signal to the EHPS through the BPP sensor signal circuit. Brake pedal position sensor calibration must be performed after the brake pedal position sensor or EHPS system has been serviced. The calibration procedure will set brake pedal position sensor home value. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Calibration Procedure 1. Install a scan tool. 2. Turn ON the ignition, with the engine OFF. 3. Navigate to the Special Functions screen on the scan tool and select BPP Sensor Calibration in order to perform the brake pedal position sensor calibration. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

SATURN VUE AND CHEVROLET MALIBU HYBRIDS The Saturn VUE and the Chevrolet Malibu hybrid systems offer start/stop and regenerative braking from the Belt Alternator Starter (BAS) system. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

A dual-tensioner assembly for the hybrid accessory drive (the motor/generator package) allows for the transfer of a small amount of torque to the drive system for very brief periods of time. The assembly combines a hydraulic strut tensioner and a friction-damped rotary tensioner on a common pivoting arm to control the bi-directional loads (motoring and generating). Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Power assist takes three forms: 1. Electrically motored creep at startup 2. Light power assist during acceleration 3. Light regenerative mode during deceleration Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

The system consists of six elements: The electric motor/generator unit that replaces the alternator, and is capable of 115 lb-ft (156 Nm) of auto-start torque Engine-coolant-cooled power electronics that control the motor/generator unit and provide 12 -volt vehicle accessory power A 36 -volt Ni. MH hybrid battery pack capable of delivering and receiving more than 10 k. W of peak power (the battery pack is under the rear seat) An engine control module An engine accessory drive using a dual-tensioner assembly and cord belt that enables transfer of motoring and generating torque Hybrid-enabled Hydra-Matic 4 T 45 -E electronically controlled four-speed automatic transaxle that includes an auxiliary oil pump and unique hybrid controls Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

GENERAL MOTORS TWO-MODE HYBRID The two-mode system is under joint development by General Motors, Daimler. Chrysler, and BMW. The two-mode hybrid system is designed to optimize power and torque for different types of driving conditions. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

. In the first mode, the vehicle can operate in three ways: Electric power only Engine power only Any combination of engine and electric power Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

The second mode is used primarily at highway speeds to optimize fuel economy while providing full engine power when conditions demand it, such as trailer towing or climbing steep grades. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Like all hybrids, the two-mode combines the power of a gasoline engine with that of electric motors and includes: Regenerative braking that captures kinetic energy that would otherwise be lost Idle stop The two-mode hybrid is a full (strong) hybrid and is capable of being powered by electric motor power alone. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Existing hybrid systems have a single mode of operation, using a single planetary gearset to split the engine's power - routing it to drive the wheels or charge the battery - for both city and highway driving. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

These systems are effective at low speeds because they can move the vehicle without running the ICE. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

The two-mode system also has a variable transmission but adds two planetary gearsets (which multiply the torque from the power source). This arrangement provides two operating modes for the electric motors. The first is for accelerating from a standstill to second gear; another phase takes the vehicle from second gear to overdrive. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

Because the torque is multiplied by the gears, the electric motors can be much smaller and fit in the same housing as the transmission. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

SUMMARY 1. The General Motors parallel hybrid truck (PHT) uses three conventional VRLA 12 -volt batteries connected in series to provide 36 volts (42 volts charging). 2. The flywheel alternator starter (FAS) is used to start the gasoline engine, provide torque smoothly and generate electrical energy for the 110 -volt outlets. 3. The PHT has four auxiliary power outlets (APOs) – two at the base of the rear seat and two in the bed of the truck. 4. The PHT uses an electro-hydraulic power steering (EHPS) system that uses the 36 volts from the battery pack to power the hydraulic pump. 5. The Saturn VUE and Chevrolet Malibu hybrid vehicles use a Belt Alternator Starter (BAS) system and use 36 -volt Ni. MH batteries. 6. The General Motors two-mode hybrid electric vehicle uses two 60 -k. W electric motors inside the transmission and can power the vehicle using electrical energy alone. 7. The two-mode hybrid vehicle is a full (strong) hybrid and uses 300 -volt Ni. MH batteries located under the rear seat. Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458

REVIEW QUESTIONS 1. How is the General Motors parallel hybrid truck able to supply 110 volts AC to the auxiliary power outlet? 2. What type of hybrid vehicle is the GM PHT truck, and what are its capabilities? 3. How does the electro-hydraulic power steering (EHPS) work? 4. How does the Belt Alternator Starter (BAS) system work? 5. How does the two-mode hybrid system work? Hybrid and Alternative Fuel Vehicles By James D Halderman and Tony Martin © 2009 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458