Technical Service Training Global Fundamentals Curriculum Training – TF1010012S Climate Control H C RPM X 1000 60 40 60 80 100 80 120 VOL - PUSH ON 140 100 MPH 180 km/h 120 AM FM 4x4 160 40 20 20 SCN ST FM1 BASS F TREB BAL FADE CD AUTO SET E DISC SEEK EJ TUNE COMP CD CD SHUFFLE RSM SET ACC ON CST OFF 4X4 AUTO ON A/C AC MAX A/C A/C AC MAX A/C Student Information FCS-13198-REF CG7968/S en 12/2001 Copyright © 2001 Ford Motor Company Introduction Preface Global fundamentals training overview The goal of the Global Fundamentals Training is to provide students with a common knowledge base of the theory and operation of automotive systems and components The Global Fundamentals Training Curriculum (FCS-13203-REF) consists of nine self-study books A brief listing of the topics covered in each of the self-study books appears below l Shop Practices (FCS-13202-REF) explains how to prepare for work and describes procedures for lifting materials and vehicles, handling substances safely, and performing potentially hazardous activities (such as welding) Understanding hazard labels, using protective equipment, the importance of environmental policy, and using technical resources are also covered l Brake Systems (FCS-13201-REF) describes the function and operation of drum brakes, disc brakes, master cylinder and brake lines, power-assist brakes, and anti-lock braking systems l Steering and Suspension Systems (FCS-13196-REF) describes the function and operation of the powerassisted steering system, tires and wheels, the suspension system, and steering alignment l Climate Control (FCS-13198-REF) explains the theories behind climate control systems, such as heat transfer and the relationship of temperature to pressure The self-study also describes the function and operation of the refrigeration systems, the air distribution system, the ventilation system, and the electrical control system l Electrical Systems (FCS-13197-REF) explains the theories related to electricity, including the characteristics of electricity and basic circuits The self-study also describes the function and operation of common automotive electrical and electronic devices l Manual Transmission and Drivetrain (FCS-13199-REF) explains the theory and operation of gears The self-study also describes the function and operation of the drivetrain, the clutch, manual transmissions and transaxles, the driveshaft, the rear axle and differential, the transfer case, and the 4x4 system l Automatic Transmissions (FCS-13200-REF) explains the function and operation of the transmission and transaxle, the mechanical system, the hydraulic control system, the electronic control system, and the transaxle final drive The self-study also describes the theory behind automatic transmissions including mechanical powerflow and electro-hydraulic operation l Engine Operation (FCS-13195-REF) explains the four-stroke process and the function and operation of the engine block assembly and the valve train Also described are the lubrication system, the intake air system, the exhaust system, and the cooling system Diesel engine function and operation are covered also l Engine Performance (FCS-13194-REF) explains the combustion process and the resulting emissions The self-study book also describes the function and operation of the powertrain control system, the fuel injection system, the ignition system, emissions control devices, the forced induction systems, and diesel engine fuel injection Read Engine Operation before completing Engine Performance To order curriculum or individual self-study books, contact Helm Inc Toll Free: 1-800-782-4356 (8:00 am – 6:00 pm EST) Mail: 14310 Hamilton Ave., Highland Park, MI 48203 USA Internet: www.helminc.com (24 hours a day, days a week) Service Training Contents Introduction Introduction Preface Global fundamentals training overview Contents Lesson – Climate control theory General Objectives At a glance Climate control system Theory Heat energy Humidity 11 Heat movement 11 Lesson – Refrigeration system 17 General 17 Objectives 17 Overview 18 Refrigerants 18 Handling refrigerant 21 Components 24 Refrigeration system components 24 Operation 29 Lubricant 29 Refrigeration cycle is an expansion valve system 30 Heating system 36 Lesson – Air distribution system 37 General 37 Objectives 37 At a glance 38 Air distribution system 38 Air ventilation system 39 Air distribution ventilation system 40 Components 41 Air distribution ventilation system 41 Air distribution controls 43 Service Training Introduction Contents Lesson – Electrical control system 46 General 46 Objectives 46 At a glance 47 Electrical control system 47 Components 48 Blower Switch 48 Blower motor 48 Air condition compressor clutch controls 49 Thermostatic switch 49 Pressure cycling switch 50 High and low-pressure switches 51 Condenser temperature fan control 52 Climate control electrical controller 52 Lesson – Diagnostic procedure 53 General 53 Objective 53 Overview 54 Symptom-to-system-to-component-to-cause diagnosis 54 Workshop manual 55 List of abbreviations 56 Service Training General Lesson – Climate control theory Objectives Upon completion of this lesson you will be able to: l Explain the purpose and function of the climate control system l Describe the climate control system and identify the types l Identify the components of the climate control system l Explain the theory and operation of a climate control system Service Training Lesson – Climate control theory At a glance Climate control system RPM X 1000 60 40 60 H C 80 100 80 120 VOL - PUSH ON 140 100 MPH 180 km/h 120 AM FM 4x4 160 40 20 20 SCN ST FM1 BASS F TREB BAL FADE CD AUTO SET E DISC SEEK EJ TUNE COMP CD CD SHUFFLE RSM SET ACC ON CST OFF 4X4 AUTO ON A/C AC MAX A/C A/C AC MAX A/C ACH003-A/VF Electrical system components Blower speed control Air distribution control switch Heating and cooling temperature control The climate control system is designed to provide comfort for the driver and passengers The climate control system maintains in-car air temperature and humidity within a range that is comfortable for the people inside and provides fresh clean air for ventilation A comfortable temperature inside the vehicle helps keep the driver alert and attentive Service Training At a glance Lesson – Climate control theory Climate control system (continued) ACH002-A/VF Air distribution system components Defroster vents Air distribution ducts Outside air intake Face vents Floor vent Dashboard The air conditioning (A/C) system and the heating system are known together as heating, ventilation and air conditioning (HVAC) system The HVAC system controls heat, temperature, air distribution, and the removal of humidity The HVAC system uses an air distribution system of ducts, vents and doors to direct outside air or climate controlled air into the vehicle passenger compartment An electrical system provides the operator control of the HVAC system Service Training Lesson – Climate control theory At a glance ACH001-A/VF Air conditioning components Air conditioning compressor Air conditioning clutch assembly Condenser Air conditioning refrigerant lines Expansion valve or orifice tube Accumulator drier or receiver drier Evaporator The HVAC system in a vehicle is divided into four closely related subsystems: l Refrigeration, A/C system l Heating system l Air distribution and ventilation system l Electrical system Service Training Theory Lesson – Climate control theory Heat energy Air conditioning is the control of heat Heat is a form of energy Energy cannot be destroyed, but can be converted into another form of energy Air conditioning systems use heat and energy from the vehicle’s engine to remove unwanted heat from the interior of the vehicle An example of energy conversion is a flame under a container of water The heat from the flame raises the temperature of the water causing the water to boil The expanding gases or steam from the boiling water can be used to create mechanical motion, another form of energy Along with the concept of heat and heat energy comes the concept of cold Heat measurement Cold is merely the absence of heat Cold is what is left if all heat is removed Heat will always travel to cold An example of this is a cooking pan on a hot stove The heat on the bottom of the pan will travel toward the cold handle Heat is relatively easy to measure and its methods of movement are very predictable and controllable Vehicle air conditioning systems create a cold spot in the interior of the vehicle, giving the heat a cold area to transfer to ACH004-A/VF Heat movement Pan Handle Heat source Service Training Components Lesson – Air distribution theory Air distribution ventilation system (continued) Vent/face heater doors The vent/face and heater doors direct air either to the floor vents or the upper vents If the operator selects the multiple-level position, air flows to both sets of vents ACH039-A/VF Vent/face heater door operation 42 Vent doors Heater core Evaporator Defroster door Service Training Lesson – Air distribution theory Components Air distribution controls ACHO40-A/VF Cable system door controls Floor defrost/door linkage Function selector cable Temperature cable Floor defrost door Control head at dashboard Air distribution doors can be controlled using steel or wire-like cables, engine vacuum or electrically actuated door controls Service Training 43 Components Lesson – Air distribution theory Air distribution controls (continued) Cable type air distribution system door controls The most basic form of air distribution door control is the cable This type of control uses a manually operated lever or knob that pivots in the center and has a cable attached to one end As the lever of knob is moved, the cable pulls or pushes an arm that is connected to the door being controlled This type of control can be used on any of the distribution doors Vacuum motor type air distribution system door controls Vacuum motors are also controlled by the position of knobs or levers When a lever or knob is pushed or pulled, vacuum is allowed to flow against a rubber diaphragm inside the vacuum motor With vacuum on one side of the rubber diaphragm and atmospheric pressure on the opposite side the diaphragm forces a rod that is attached to it and opens or closes an air distribution door ACH042-A/VF Vacuum system door controls Vacuum line Vacuum motor Air inlet duct door 44 Service Training Lesson – Air distribution theory Components Electronic actuator controls/air distribution system door controls Electronic actuators provide precise movement of air distribution door controls and can provide feedback to a computer operating them Pushbuttons, levers or knobs can all be used to operate the electronic door actuator ACH041-A/VF Electronic system door controls Electronic door actuator motor Temperature blend door pivot point Actuator arm Service Training 45 General Lesson – Electrical control system Objectives Upon completion of this lesson you will be able to: l Explain the purpose and function of the electrical control system l Describe the electrical control system l Identify the components of the electrical control system l Explain the theory and operation of the electrical control system 46 Service Training Lesson – Electrical control system At a glance Electrical control system OFF A/C MAX A/C ACH052-A/VF Electrical control system components Blower switch Thermostatic switch Pressure cycling switch/high and low pressure switches Electronic climate control module A/C compressor Blower motor Electronic door actuator The electrical control system provides the operator control of blower motor speeds, discharge air temperature, airflow distribution and HVAC system controls and protection devices Service Training 47 Components Lesson – Electrical control system Blower switch The blower switch controls the on and off operation of the blower motor and may also be used to control blower speed or air distribution discharge volume One side of the switch is wired to a battery source and ˚C the other side of the blower switch sends voltage to the blower motor when the vehicle operator moves A/C the switch to the ON position ACH053-A/VF Blower switch and controls Blower motor The blower motor, after receiving electrical power from the blower switch, rotates a fan that pushes or pulls air past the heater core and evaporator, cooling or heating the passing air depending on climate temperature control settings The air is then routed to the air distribution system ACH044-A/VF Blower motor components 48 Evaporator Refrigerant inlet from evaporator Refrigerant outlet from evaporator Blower motor assembly Service Training Lesson – Electrical control system Components Air conditioner compressor clutch controls The air conditioner compressor has to have some means to turn the compressor on and off to prevent damage and prevent the evaporator from freezing The air conditioning compressor clutch works by electricity and magnetism The clutch allows the compressor to be turned on and off using electrical signals When electrical power flows to the clutch, a magnetic force is created and this force moves a friction disk against the rotating compressor pulley The compressor is now linked through the clutch to the engine drive belt The engine A/C compressor drive belt turns the shaft of the compressor and the refrigeration begins ACH054-A/VF A/C compressor clutch components Friction disk and clutch assembly A/C compressor Belt driven pulley Thermostatic switch Power from the A/C on and off switch operated by the vehicle operator flows through the thermostatic switch before flowing out to the A/C clutch If the evaporator is warm and is not in danger of freezing, power is allowed to flow through the thermostatic switch to the A/C compressor clutch This electrical power allows the clutch to engage and the compressor to operate The thermostatic switch has a long probe that is filled with a substance that expands or contracts when hot or cold The expansion or contraction opens or closes electrical contacts inside the switch The thermostatic switch does not allow power to flow through the thermostatic switch and to ACH055-A/VF Thermostatic switch components Power input terminal Power output terminal Sensing probe the A/C clutch when the evaporator becomes too cold The thermostatic switch is normally used on A/C systems where an expansion valve is used Some systems use a temperature sensor and an electronic control module instead of a thermostatic switch to cycle the compressor clutch Service Training 49 Components Lesson – Electrical control system Pressure cycling switch The pressure cycling switch works in the same fashion as the thermostatic switch The pressure cycling switch monitors pressure in the accumulator or receiver/drier system and shuts off the power supply to the A/C compressor clutch if pressure rises or falls below the manufacturer’s specifications ACH046-A/VF Pressure cycling switch components 50 Refrigerant inlet Pressure cycling switch Refrigerant outlet Accumulator receiver/drier Service Training Lesson – Electrical control system Components High and low-pressure switches High and low-pressure switches monitor refrigerant pressure in both the high and low sides of the refrigeration system The high side pressure relief switch and valve protects the system from excessive high side system pressure that may cause an A/C component to burst The low side pressure switch protects the system from working if there is a loss of system refrigerant The lubricating oil in the A/C system flows with the refrigerant, and if refrigerant pressure is lost the oil cannot circulate and system damage occurs Both the low and high side pressure switches allow or prevent electrical power from flowing to the A/C compressor clutch, allowing or preventing compressor operation ACH047-A/VF Pressure switches High-pressure switch Low-pressure switch Service Training 51 Components Lesson – Electrical control system Condenser temperature fan control The condenser temperature fan control monitors the temperature of the refrigerant flowing through the condenser If the control monitor determines that the temperature of the refrigerant is too high, the engine temperature coolant fan turns on and the refrigerant temperature is lowered The refrigerant is cooled by the passing airflow that is pulled through the condenser by the engine coolant fan ACH056-A/VF Temperature fan control sensor location Condenser Condenser temperature sensor Climate control electrical controller Many vehicles have electronic climate control systems to monitor interior vehicle temperature settings and adjust the vehicles interior temperature and air distribution accordingly The climate control electrical controller takes in information such as refrigerant temperature and pressure, heater and fresh air door position along with blend door position to adjust the interior output air to the desired temperature The climate control electrical controller also communicates with other vehicle computers to allow the system and the vehicle to perform as intended by the designer 52 Service Training Lesson – Diagnostic process General Objective Upon completion of this lesson you will be able to: l Explain the symptom-to-system-to-component-to-cause diagnostic process Service Training 53 At a glance Lesson – Diagnostic process Symptom-to-system-to-component-to-cause diagnostic process Diagnosis requires a complete knowledge of the For example, if the A/C system is low on refrigerant, system operation As with all diagnosis, a technician adding refrigerant may correct the problem for a short must use symptoms and clues to determine the cause time but finding and repairing the leak that is causing of a vehicle concern To aid the technician when the refrigerant to leak corrects the problem and diagnosing vehicles, the strategies of many successful repairs the vehicle correctly the first time technicians have been analyzed and incorporated into a diagnostic strategy and into many service publications Symptom-to-system-to-component-to-cause diagnostic process Using the "Symptom-to-System-to-Component-to2 Cause" diagnostic process provides you with a logical 2 method for correcting customer concerns: l First, confirm the "Symptom" of the customer’s concern l Next, determine which "System" on the vehicle could be causing the symptom l Once you identify the particular system, determine which "Component(s)" within that system could be the cause for the customer concern l After determining the faulty component(s) you should always try to identify the cause of the failure In some cases parts just wear out However, in other instances something other than the failed component is responsible for the problem 54 3 3 ACH057-A/VF Symptom Vehicle systems Components Causes Service Training Lesson – Diagnostic process At a glance Workshop literature The vehicle workshop literature contains information about climate control diagnostic steps and checks, such as preliminary checks, verification of customer concern or special driving conditions, road test, and diagnostic pinpoint tests Service Training 55 Climate control List of abbreviations A/C Air Conditioning HVAC Heating Ventilation Air Conditioning BTU British Thermal Units x 251 = calorie J Joule Joule = 238 CAL or 000947 BTU CAL Calories x 0039 = BTU kPa kiloPascals x 0.145 psi, 100 kPa = bar C° Celsius (C° x 1.8) + 32 = Fahrenheit PAG Polyalkaline glycol (a synthetic oil) psi pounds per square inch x 6.89 = kPa F° Fahrenheit (F° x 0.556) – 32 = Celsius Gasoline Petrol g Gram 56 Service Training ... components of the climate control system l Explain the theory and operation of a climate control system Service Training Lesson – Climate control theory At a glance Climate control system RPM... speed control Air distribution control switch Heating and cooling temperature control The climate control system is designed to provide comfort for the driver and passengers The climate control. .. Lesson – Climate control theory Objectives Upon completion of this lesson you will be able to: l Explain the purpose and function of the climate control system l Describe the climate control system