Ford training section1 description and operation

Vehicle Emission Control Information VECI...1-1 Vehicle Certification Label ...1-5 Base Engine Calibration Information...1-5 Vehicle Emission Control Information VECI Acronym Definitions

Vehicle Emission Control Information (VECI) 1-1 Vehicle Certification Label 1-5 Base Engine Calibration Information 1-5 Vehicle Emission Control Information (VECI) Acronym

Definitions 1-8 Engine Control Components 1-10 Accelerator Pedal Position (APP) Sensor 1-10 Ambient Air Temperature (AAT) Sensor 1-11 Barometric Pressure (BARO) Sensor 1-12 Brake Pedal Position (BPP) Switch 1-12 Brake Pressure Switch 1-13 Camshaft Position (CMP) Sensor 1-13 Canister Vent (CV) Solenoid 1-14 Charge Air Cooler Temperature (CACT) Sensor 1-15 Check Fuel Cap Indicator 1-15 Clutch Pedal Position (CPP) Switch 1-15 Coil On Plug (COP) 1-16

Contents (Continued)

Coil Pack 1-16 Crankshaft Position (CKP) Sensor 1-18 Cylinder Head Temperature (CHT) Sensor 1-19 Differential Pressure Feedback Exhaust Gas

Recirculation (EGR) Sensor 1-19 Electric Cooling Fan 1-21 Electric Exhaust Gas Recirculation (EEGR) Valve 1-22 Electronic Throttle Actuator Control (TAC) 1-23 Electronic Throttle Body Throttle Position Sensor

(ETBTPS) 1-24 Engine Coolant Temperature (ECT) Sensor 1-24 Engine Oil Temperature (EOT) Sensor 1-24 Evaporative Emission (EVAP) Canister Purge Valve 1-25 Evaporative Emission (EVAP) Canister Purge Check

Valve 1-26 Evaporative Emission (EVAP) Natural Vacuum Leak

Detection (NVLD) Module 1-27 Exhaust Gas Recirculation (EGR) Orifice Tube

Assembly 1-28

Contents (Continued)

Exhaust Gas Recirculation (EGR) System Module (ESM) 1-28 Exhaust Gas Recirculation (EGR) Vacuum Regulator

Solenoid 1-29 Exhaust Gas Recirculation (EGR) Valve 1-30 Fan Control 1-31 Fan Speed Sensor (FSS) 1-33 Fuel Injection Pump 1-33 Fuel Injectors 1-35 Fuel Injectors — Direct Injection 1-35 Fuel Pump (FP) Module 1-36 Fuel Pump (FP) Module and Reservoir 1-38 Fuel Rail Pressure (FRP) Sensor 1-38 Fuel Rail Pressure Temperature (FRPT) Sensor 1-38 Fuel Tank Pressure (FTP) Sensor 1-39 Heated Oxygen Sensor (HO2S) 1-40 Idle Air Control (IAC) Valve 1-41 Inertia Fuel Shut-off (IFS) Switch 1-42

Contents (Continued)

Intake Air Temperature (IAT) Sensor 1-42 Intake Manifold Tuning Valve (IMTV) 1-44 Knock Sensor (KS) 1-45 Manifold Absolute Pressure (MAP) Sensor 1-45 Mass Air Flow (MAF) Sensor 1-46 Output Shaft Speed (OSS) Sensor 1-48 Power Steering Pressure (PSP) Sensor 1-48 Power Steering Pressure (PSP) Switch 1-49 Power Take-Off (PTO) Switch and Circuits 1-49 Throttle Position (TP) Sensor 1-50 Transmission Control Indicator Lamp (TCIL) 1-50 Transmission Control Switch (TCS) 1-50 Turbocharger 1-51 Turbocharger Boost Pressure (TCBP) Sensor 1-52 Turbocharger Bypass (TCBY) Valve 1-52 Turbocharger (TC) Wastegate Regulating Solenoid

Valve 1-53 Universal Heated Oxygen Sensor (HO2S) 1-53

Contents (Continued)

Vehicle Speed Sensor (VSS) 1-54 Engine Control (EC) System 1-55 Powertrain Control Hardware 1-57 Powertrain Control Module (PCM) 1-57 PCM Locations 1-57 Fuel Pump Control Module 1-61 Fuel Pump Driver Module (FPDM) 1-62 Keep Alive Memory (KAM) 1-62 Power and Ground Signals 1-62 Powertrain Control Module - Vehicle Speed Output

(PCM-VSO) 1-64 Powertrain Control Software 1-66 Adaptive Airflow 1-66 Check Fuel Cap Indicator 1-66 Computer Controlled Shutdown 1-66 Deceleration Fuel Shut-Off (DFSO) 1-66 Engine Fluid Temperature Management 1-66 Engine RPM And Vehicle Speed Limiter 1-67

Contents (Continued)

Fail-Safe Cooling Strategy 1-67 Failure Mode Effects Management (FMEM) 1-68 Flash Electrically Erasable Programmable Read Only

Memory (EEPROM) 1-68 Fuel Level Input (FLI) 1-68 Fuel Trim 1-68 High Speed Controller Area Network (CAN) 1-69 Idle Air Trim 1-69 Idle Speed Control Closed Throttle Determination —

Applications Without Electronic Throttle Control (ETC) 1-70 International Standards Organization (ISO) 14229

Diagnostic Trouble Code (DTC) Descriptions 1-70 Multiplexing 1-74 Multiplexing Implementation 1-74 Permanent Diagnostic Trouble Code (DTC) 1-75 Malfunction Indicator Lamp (MIL) 1-76 Catalyst and Exhaust Systems 1-77 Evaporative Emission (EVAP) Systems 1-82 Exhaust Gas Recirculation (EGR) Systems 1-85

Contents (Continued)

Differential Pressure Feedback Exhaust Gas Recirculation (EGR) System 1-85 Electric Exhaust Gas Recirculation (EEGR) System 1-86 Exhaust Gas Recirculation (EGR) System Module

(ESM) 1-87 Fuel Systems 1-90 Electronic Returnless Fuel System (ERFS) 1-90 Fuel Pump Control — ERFS 1-92 Fuel Pump Monitor (FPM) — ERFS 1-94 Mechanical Returnless Fuel System (MRFS) — Single

Speed 1-95 Fuel Pump Control — Single Speed MRFS 1-96 Fuel Pump Monitor (FPM) — Single Speed MRFS 1-97 Mechanical Returnless Fuel System (MRFS) — Dual

Speed 1-97 Fuel Pump Control — Dual Speed MRFS 1-99 Fuel Pump Monitor (FPM) — Dual Speed MRFS 1-99 High Pressure Fuel System 1-101 Ignition Systems 1-103

Contents (Continued)

Intake Air Systems 1-107 Positive Crankcase Ventilation (PCV) System 1-115 Supercharger and Charge Air Cooler (CAC) Systems 1-118 Torque Based Electronic Throttle Control (ETC) 1-122 Turbocharger and Charge Air Cooler (CAC) Systems 1-128 Variable Camshaft Timing (VCT) System 1-132

On Board Diagnostics (OBD) Monitors 1-135 OBD I, OBD II and Engine Manufacturer Diagnostics

(EMD) Overview 1-135 Air Fuel Ratio Imbalance Monitor 1-139 Catalyst Efficiency Monitor 1-140 General Catalyst Monitor Operation 1-142 Integrated Air Fuel Catalyst Monitor 1-143 Cold Start Emission Reduction Monitor 1-144 Comprehensive Component Monitor (CCM) 1-148 Electric Exhaust Gas Recirculation (EEGR) System

Monitor 1-150 Enhanced Thermostat Monitor 1-153

Contents (Continued)

Evaporative Emission (EVAP) Leak Check Monitor 1-154 Engine On EVAP Leak Check Monitor — Fiesta 1-154 Engine On EVAP Leak Check Monitor — All Others 1-155 Engine Off Natural Vacuum (EONV) EVAP Leak Check

Monitor 1-157 Natural Vacuum Leak Detection (NVLD) Small Leak

Monitor 1-160 Exhaust Gas Recirculation (EGR) System Monitor —

Differential Pressure Feedback EGR and EGR System Module (ESM) 1-162 Fuel System Monitor 1-164 Heated Oxygen Sensor (HO2S) Monitor 1-166 Misfire Detection Monitor 1-168 Positive Crankcase Ventilation (PCV) System Monitor 1-174 Thermostat Monitor 1-175 Variable Camshaft Timing (VCT) Monitor 1-177

VECI Decal

Each vehicle has a VECI decal containing emission control information that applies specifically tothe vehicle and engine The specifications on the decal are critical to repairing the emissions

systems

Typical VECI Decal

VECI Decal Location

The decal is typically located on the underside of the hood or on the radiator support sight shield

Engine/Evaporative Emission (EVAP) System Information

Manufacturers must use a standardized system for identifying their individual engine families Thesystem described below was developed by the Environmental Protection Agency (EPA) in 1991 tomeet new regulatory requirements for 1994 and later model years

The engine family group and evaporative family name consist of 12 characters each

Both the engine family group and the evaporative family name are listed in the box on the

emission decal in the area marked as engine evaporative family information The first line containsengine size and the 12-character engine family group The second line contains the 12-characterevaporative family name information Both the engine family group and the evaporative family

name are specific to the vehicle Refer to the Engine Family Group and the Evaporative FamilyName worksheet for decoding information

Typical VECI Decal

Part

1 — Exhaust Emission Control

Base Engine Calibration Information

Base engine calibration information, sometimes referred to as the powertrain calibration, is located

in the lower right corner of the vehicle certification label Engine calibration information is limited to

a maximum of 5 characters per line (2 lines maximum) Calibration information more than 5

characters long wraps to the second line of this field Only the base calibration appears on thislabel The revision level is no longer printed on the label However, it can be found in the On-LineAutomotive Service Information System (OASIS) For additional information on the vehicle

certification label or engine calibration, refer to the Workshop Manual Section 100-01, IdentificationCodes

Engine Calibration Information (Car)

Typical Car Vehicle Certification Label

Engine Calibration Information (Truck)

Typical Truck Vehicle Certification Label

Vehicle Certification Label Location

The vehicle certification label is typically located on the LH door or door post pillar

Engine Calibration Code

2011 Model Year Example

Engine Calibration Code: BB7 1 4D 0 A 00

B MODEL YEAR — Model year in which the calibration was first introduced B equals

2011 B7 VEHICLE CODE — Vehicle line description B7 equals Expedition

1 TRANSMISSION CODE — Transmission description 1 equals automatic, 2 equals

manual 4D UNIQUE CALIBRATION — Identifications are assigned to cover similar vehicles to

differentiate between tires, drive configurations, final drive ratios and other calibration-significant factors.

0 FLEET CODE — Describes which fleet the vehicle belongs to 0 equals Certification

(U.S 4K)

(Continued)

2011 Model Year Example

Engine Calibration Code: BB7 1 4D 0 A 00

A CERTIFICATION REGION — Lead region code where multiple regions are included

in one calibration A equals U.S Federal

00 REVISION LEVEL — Revision level of the calibration 00 equals Job 1 production or

initial calibration (Not printed on vehicle certification label)

CAC: Charge Air Cooler

CARB: California Air Resource Board

CARB LEV: Low Emission Vehicle

CARB SULEV: Super Ultra Low Emission Vehicle

CARB TLEV: Transitional Low Emission Vehicle

CARB ULEV: Ultra Low Emission Vehicle

CARB ZEV: Zero Emission Vehicle

CI: Cylinder Injection

DGI: Direct Gas Injection

EPA: Environmental Protection Agency

EVAP: Evaporative Emission

GVW: Gross Vehicle Weight

GVWR: Gross Vehicle Weight Rating, curb weight plus payload

HHDDE: Heavy Heavy Duty Diesel Engine

HHDE: Heavy Heavy Duty Engine

HO2S: Heated Oxygen Sensor

ILEV: Inherently Low Emission Vehicle

LDDT: Light Duty Diesel Truck categories

LDT: Light Duty Truck (gasoline) categories based on weight as defined in the table

LDV: Light Duty Vehicle, generally passenger cars and light trucks under 2,721.55 Kg (6,000 lb)GVWR

LEV: Low Emission Vehicle

LEV-II: California regulations beginning in the 2004 model year

LHDE: Light Heavy Duty Engine (several weight categories)

LVW: Loaded Vehicle Weight, curb weight plus 136.08 Kg (300 lb)

MDPV: Medium Duty Passenger Vehicle

MDT: Medium Duty Truck categories based on weight as defined in the table

MDV: Medium Duty Vehicle

MHDDE: Medium Heavy Duty Diesel Engine

MHDE: Medium Heavy Duty Engine

MPI: Multi-Port Injection

MY: Model Year

NCP: Non-Compliance Penalty

OBD: On Board Diagnostics

ORVR: On Board Refueling Vapor Recovery

PC: Passenger Car

PZEV: Partial Zero Emission Vehicle

SFI: Sequential Multiport Fuel Injection

SI: Sequential Injection

SULEV: Super Ultra Low Emission Vehicle

TC: Turbocharged

Tier 0: California and Federal regulations effective prior to Tier 1 phase in dates

Tier 1: California regulations beginning in 1993 model year and Federal regulations beginning in

1994 model year

Tier 2: Federal regulations beginning in the 2004 model year

TWC: Three-Way Catalytic Converter

ULEV: Ultra Low Emission Vehicle

ZEV: Zero Emission Vehicle

Note: Transmission inputs which are not described in this section are discussed in the applicable

Workshop Manual transmission section

Accelerator Pedal Position (APP) Sensor

The APP sensor is an input to the powertrain control module (PCM) and used to determine theamount of torque requested by the operator Depending on the application, either a 2 track or 3track APP sensor is used

2 Track APP Sensor — Fiesta

There are 2 separate pedal position sensors in the accelerator pedal The APP1 sensor signal

generates a pulse width modulated signal to the PCM The APP1 sensor uses a VPWR circuit, aground circuit and a signal circuit Only the APP1 signal circuit is connected to the PCM The

APP2 sensor signal has a positive slope (increasing angle, increasing voltage) and is a class 2message from the instrument panel cluster (IPC) to the PCM The APP2 sensor uses a referencevoltage circuit, a signal return circuit, and a signal circuit between the IPC and the APP sensor

assembly The two pedal position signals make sure the PCM receives a correct input even if one

of the signals has a concern The PCM determines if a signal is incorrect by calculating an

expected position, inferred from the other signals If a concern is present with one of the circuitsthe other input is used The pedal position signal is converted to pedal travel degrees (rotary

angle) by the PCM The software converts these degrees to counts, which is the input to the

torque based strategy For additional information, refer to Torque-Based Electronic Throttle Control(ETC) in this section

2 Track APP Sensor — All Others

There are 2 pedal position signals in the sensor Both signals, APP and APP2, have a positive

slope (increasing angle, increasing voltage), but are offset and increase at different rates The 2pedal position signals make sure the PCM receives a correct input even if 1 signal has a concern.The PCM determines if a signal is incorrect by calculating where it should be, inferred from theother signals If a concern is present with one of the circuits the other input is used There are 2reference voltage circuits, 2 signal return circuits, and 2 signal circuits (a total of 6 circuits and

pins) between the PCM and the APP sensor assembly The pedal position signal is converted topedal travel degrees (rotary angle) by the PCM The software converts these degrees to counts,which is the input to the torque based strategy For additional information, refer to Torque-BasedElectronic Throttle Control (ETC) in this section

Typical 2 Track APP Sensor

3 Track APP Sensor

There are 3 pedal position signals in the sensor Signal 1, APP, has a negative slope (increasingangle, decreasing voltage) and signals 2 and 3, APP2 and APP3, both have a positive slope

(increasing angle, increasing voltage) During normal operation, APP is used as the indication ofpedal position by the strategy The 3 pedal position signals make sure the PCM receives a correctinput even if one signal has a concern The PCM determines if a signal is incorrect by calculatingwhere it should be, inferred from the other signals If a concern is present with one of the circuitsthe other inputs are used The pedal position signal is converted to pedal travel degrees (rotaryangle) by the PCM The software converts these degrees to counts, which is the input to the

torque based strategy There are 2 reference voltage circuits, 2 signal return circuits, and 3 signalcircuits (a total of 7 circuits and pins) between the PCM and the APP sensor assembly

Typical 3 Track APP Sensor

Ambient Air Temperature (AAT) Sensor

The AAT sensor is a thermistor device in which resistance changes with temperature The

electrical resistance of a thermistor decreases as the temperature increases, and the resistanceincreases as the temperature decreases The varying resistance affects the voltage drop across

Thermistor-type sensors are considered passive sensors A passive sensor is connected to a

voltage divider network so that varying the resistance of the passive sensor causes a variation intotal current flow Voltage that is dropped across a fixed resistor in a series with the sensor

resistor determines the voltage signal at the PCM This voltage signal is equal to the referencevoltage minus the voltage drop across the fixed resistor

The AAT sensor provides ambient air temperature information to the PCM for the temperature

sensor correlation tests The PCM also communicates the AAT sensor information to all other

modules on the controller area network (CAN)

Typical AAT Sensor

Barometric Pressure (BARO) Sensor

The BARO sensor directly measures barometric pressure to estimate the exhaust back pressure.Exhaust back pressure influences speed density based air charge computation The BARO sensor

is mounted directly to the PCM circuit board

Brake Pedal Position (BPP) Switch

The BPP switch is sometimes referred to as the stoplamp switch The BPP switch provides a

signal to the PCM indicating the brakes are applied The BPP switch is normally open and

mounted on the brake pedal support Depending on the vehicle application the BPP switch can behardwired as follows:

• to the PCM supplying battery positive (B+) voltage when the brake pedal is applied

• to the anti-lock brake system (ABS) module, or lighting control module (LCM), the BPP signal isthen broadcast over the network to be received by the PCM

• to the ABS traction control/stability assist module The ABS module interprets the BPP switchinput along with other ABS inputs and generates an output called the driver brake application(DBA) signal The DBA signal is then sent to the PCM and to other BPP signal users

Typical BPP Switch

Brake Pressure Switch

The brake pressure switch is used for vehicle speed control deactivation A normally closed switchsupplies battery positive (B+) voltage to the PCM when the brake pedal is not applied When thebrake pedal is applied, the normally closed switch opens and power is removed from the PCM

On some applications the normally closed brake pressure switch, along with the normally open

BPP switch, are used for a brake rationality test within the PCM The PCM misfire monitor profilelearn function may be disabled if a brake switch concern occurs If one or both brake pedal inputs

to the PCM is not changing states as expected, a diagnostic trouble code (DTC) is set by the PCMstrategy

Camshaft Position (CMP) Sensor

The CMP sensor detects the position of the camshaft The CMP sensor identifies when piston

number 1 is on its compression stroke A signal is then sent to the PCM and used for

synchronizing the sequential firing of the fuel injectors Coil on plug (COP) ignition applications usethe CMP signal to select the correct ignition coil to fire

Engines with 2 camshafts and with variable camshaft timing (VCT) are equipped with 2 CMP

sensors The second sensor is used to identify the position of the camshaft on bank 2 Engineswith 4 camshafts and with variable camshaft timing (VCT) are equipped with 4 CMP sensors The

4 sensors are used to identify the position of each camshaft

The 4 sensor system uses the following CMP signal circuit names:

• CMP11 - bank 1, intake camshaft

• CMP12 - bank 1, exhaust camshaft

• CMP21 - bank 2, intake camshaft

• CMP22 - bank 2, exhaust camshaft

The 2 pin variable reluctance sensor and the 3 pin hall effect sensor are the 2 types of CMP

sensors used

Typical Variable Reluctance CMP Sensor

Typical Hall Effect CMP Sensor

Canister Vent (CV) Solenoid

During the evaporative emissions (EVAP) leak check monitor, the CV solenoid seals the EVAPcanister from the atmospheric pressure This allows the EVAP canister purge valve to obtain thetarget vacuum in the fuel tank during the EVAP leak check monitor

Charge Air Cooler Temperature (CACT) Sensor

The CACT sensor is located in the intake air tube between the charge air cooler (CAC) and thethrottle body The CACT sensor measures the throttle inlet temperature The PCM uses the CACTsensor information to refine the estimate of the air flow rate through the throttle and to determinethe desired boost pressure The CACT sensor for a speed density system is integrated with theturbocharger boost pressure (TCBP) sensor

Typical CACT Sensor Integrated With a

TCBP Sensor

Check Fuel Cap Indicator

The check fuel cap indicator is a communications network message sent by the PCM The PCMsends the message to illuminate the lamp when the strategy determines there is a concern in theEVAP system due to the fuel filler cap or capless fuel tank filler pipe not being sealed correctly.This is detected by the inability to pull vacuum in the fuel tank after a fueling event

Clutch Pedal Position (CPP) Switch

The CPP switch is an input to the PCM indicating the clutch pedal position The PCM provides alow current voltage on the CPP circuit When the CPP switch is closed, this voltage is pulled lowthrough the signal return (SIG RTN) circuit The CPP input to the PCM is used to detect a

reduction in engine load The PCM uses the load information for mass air flow and fuel

calculations

Typical Clutch Pedal Position (CPP)

Switch

Coil On Plug (COP)

The COP ignition operates similar to a standard coil pack ignition except each plug has 1 coil perplug The COP operates in engine crank, engine running and camshaft position failure mode

effects management (FMEM) modes For additional information, refer to Ignition Systems in thissection

Typical Coil On Plug (COP)

Coil Pack

The PCM provides a grounding switch for the coil primary circuit When the switch is closed,

voltage is applied to the coil primary circuit This creates a magnetic field around the primary coil.The PCM opens the switch, causing the magnetic field to collapse, inducing the high voltage in thesecondary coil windings and firing the spark plug The spark plugs are paired so that as 1 sparkplug fires on the compression stroke, the other spark plug fires on the exhaust stroke The nexttime the coil is fired the order is reversed The next pair of spark plugs fire according to the enginefiring order

Coil packs come in 4-tower, 6-tower horizontal and 6-tower series 5 models Two adjacent coil

towers share a common coil and are called a matched pair For 6-tower coil pack (6 cylinder)

applications, the matched pairs are 1 and 5, 2 and 6, and 3 and 4 For 4-tower coil pack (4

cylinder) applications, the matched pairs are 1 and 4 and 2 and 3

When the coil is fired by the PCM, spark is delivered through the matched pair towers to their

respective spark plugs The spark plugs are fired simultaneously and are paired so that as onefires on the compression stroke, the other spark plug fires on the exhaust stroke The next timethe coil is fired, the situation is reversed The next pair of spark plugs fire according to the enginefiring order

Typical 4-Tower Coil Pack

Typical 6-Tower Coil Pack

Crankshaft Position (CKP) Sensor

The CKP sensor is a magnetic transducer mounted on the engine block adjacent to a pulse wheellocated on the crankshaft By monitoring the crankshaft mounted pulse wheel, the CKP sensor isthe primary sensor for ignition information to the PCM The pulse wheel has a total of 35 teeth

spaced 10 degrees apart with 1 empty space for a missing tooth The 6.8L 10-cylinder pulse wheelhas 39 teeth spaced 9 degrees apart and one 9 degree empty space for a missing tooth By

monitoring the pulse wheel, the CKP sensor signal indicates crankshaft position and speed

information to the PCM By monitoring the missing tooth, the CKP sensor is also able to identifypiston travel in order to synchronize the ignition system and provide a way of tracking the angularposition of the crankshaft relative to a fixed reference for the CKP sensor configuration The PCMalso uses the CKP signal to determine if a misfire has occurred by measuring rapid decelerationsbetween teeth

Typical CKP Sensor

Cylinder Head Temperature (CHT) Sensor

Note: If the CHT sensor is removed from the cylinder head for any reason it must be replaced

with a new sensor

The CHT sensor is a thermistor device in which resistance changes with the temperature The

electrical resistance of a thermistor decreases as temperature increases, and the resistance

increases as the temperature decreases The varying resistance affects the voltage drop acrossthe sensor terminals and provides electrical signals to the PCM corresponding to temperature

Thermistor-type sensors are considered passive sensors A passive sensor is connected to a

voltage divider network so varying the resistance of the passive sensor causes a variation in totalcurrent flow Voltage that is dropped across a fixed resistor (pull-up resistor) in series with the

sensor resistor determines the voltage signal at the PCM This voltage signal is equal to the

reference voltage minus the voltage drop across the fixed resistor

The CHT sensor is installed in the cylinder head and measures the metal temperature The CHTsensor provides complete engine temperature information and is used to infer coolant temperature

If the CHT sensor conveys an overheating condition to the PCM, the PCM initiates a fail-safe

cooling strategy based on information from the CHT sensor A cooling system concern, such aslow coolant or coolant loss, could cause an overheating condition As a result, damage to majorengine components could occur Using both the CHT sensor and fail-safe cooling strategy, the

PCM prevents damage by allowing air cooling of the engine and limp home capability For

additional information, refer to Powertrain Control Software for Fail-Safe Cooling Strategy in thissection

Typical CHT Sensor

Differential Pressure Feedback Exhaust Gas Recirculation (EGR) Sensor

The differential pressure feedback EGR sensor is a piezo resistive type pressure transducer thatmonitors the differential pressure across a metering orifice located in the orifice tube assembly.The differential pressure feedback EGR sensor receives this signal through 2 hoses referred to asthe downstream pressure hose (REF signal) and upstream pressure hose (HI signal) The HI andREF hose connections are marked on the differential pressure feedback EGR sensor housing foridentification (note the HI signal uses a larger diameter hose) The differential pressure feedbackEGR sensor outputs a voltage proportional to the pressure drop across the metering orifice andsupplies it to the PCM as EGR flow rate feedback

Differential Pressure Feedback EGR Sensor

Differential Pressure Feedback EGR Sensor — Tube Mounted

The tube mounted differential pressure feedback EGR sensor is identical in operation as the largerplastic differential pressure feedback EGR sensors and uses a 1.0 volt offset The HI and REF

hose connections are marked on the side of the sensor

Differential Pressure Feedback EGR Sensor — Tube Mounted

Electric Cooling Fan

The electric cooling fan is an electrically actuated viscous clutch that consists of 3 main elements:

• a working chamber

• a reservoir chamber

• a cooling fan clutch actuator valve and a fan speed sensor (FSS)

The cooling fan clutch actuator valve controls the fluid flow from the reservoir into the working

chamber Once viscous fluid is in the working chamber, shearing of the fluid results in fan rotation.The cooling fan clutch actuator valve is activated with a pulse width modulated (PWM) output

signal from the PCM By opening and closing the fluid port valve, the PCM can control the electriccooling fan speed The electric cooling fan speed is measured by a Hall-effect sensor and is

monitored by the PCM during closed loop operation

The PCM optimizes fan speed based on engine coolant temperature (ECT), engine oil temperature(EOT), transmission fluid temperature (TFT), intake air temperature (IAT), or air conditioning

requirements When an increased demand for fan speed is requested for vehicle cooling, the PCMmonitors the fan speed through the Hall-effect sensor If a fan speed increase is required, the

PCM outputs the PWM signal to the fluid port, providing the required fan speed increase

Typical Electric Cooling Fan with FSS

Electric Exhaust Gas Recirculation (EEGR) Valve

Depending on the application, the EEGR valve is either a water cooled or an air cooled

motor/valve assembly The motor is commanded to move in 52 discrete steps as it acts directly onthe EEGR valve The position of the valve determines the rate of EGR The built-in spring works toclose the valve against the motor opening force

EEGR Motor/Valve Assembly

Electronic Throttle Actuator Control (TAC)

The electronic TAC is a DC motor controlled by the PCM There are 2 designs for the TAC,

parallel and inline The parallel design has the motor under the bore parallel to the plate shaft Themotor housing is integrated into the main housing The inline design has a separate motor

housing An internal spring is used in both designs to return the throttle plate to a default position.The default position is typically a throttle angle of 7 to 8 degrees from the hard stop angle Theclosed throttle plate hard stop prevents the throttle from binding in the bore This hard stop setting

is not adjustable and is set to result in less airflow than the minimum engine airflow required atidle For additional information, refer to Torque-Based Electronic Throttle Control (ETC) in this

section

Typical Inline TAC Design Typical Parallel TAC Design

Electronic Throttle Body Throttle Position Sensor (ETBTPS)

The ETBTPS has two signal circuits in the sensor for redundancy The redundant ETBTPS signalsare required for increased monitoring The first ETBTPS signal (TPS1-NS) has a negative slope(increasing angle, decreasing voltage) and the second signal (TPS2-PS) has a positive slope

(increasing angle, increasing voltage) The two ETBTPS signals make sure the PCM receives acorrect input even if one signal has a concern For Fiesta, there is one reference voltage circuit(ETCREF) and one signal return circuit (ETCRTN) for the sensor dedicated to the ETBTPS For allothers, there is one reference voltage circuit (ETCREF) and one signal return circuit (ETCRTN) forthe sensor shared with the reference voltage circuits (APPVREF and APPVREF2) and signal

return circuits (APPRTN and APPRTN2) used by the APP sensor For additional information, refer

to Torque-Based Electronic Throttle Control (ETC) in this section

Engine Coolant Temperature (ECT) Sensor

The ECT sensor is a thermistor device in which resistance changes with temperature The

electrical resistance of a thermistor decreases as the temperature increases, and the resistanceincreases as the temperature decreases The varying resistance changes the voltage drop acrossthe sensor terminals and provides electrical signals to the PCM corresponding to temperature

Thermistor-type sensors are considered passive sensors A passive sensor is connected to a

voltage divider network so varying the resistance of the passive sensor causes a variation in totalcurrent flow Voltage that is dropped across a fixed resistor (pull-up resister) in series with the

sensor resistor determines the voltage signal at the PCM This voltage signal is equal to the

reference voltage minus the voltage drop across the fixed resistor

The ECT measures the temperature of the engine coolant The PCM uses the ECT input for fuelcontrol and for cooling fan control There are 3 types of ECT sensors; threaded, push-in, and

twist-lock The ECT sensor is located in an engine coolant passage

Typical Thread-Type ECT Sensor

Engine Oil Temperature (EOT) Sensor

The EOT sensor is a thermistor device in which resistance changes with temperature The

electrical resistance of a thermistor decreases as the temperature increases and the resistanceincreases as the temperature decreases The varying resistance changes the voltage drop acrossthe sensor terminals and provides electrical signals to the PCM corresponding to temperature

Thermistor-type sensors are considered passive sensors A passive sensor is connected to a

voltage divider network so that varying the resistance of the passive sensor causes a variation intotal current flow Voltage that is dropped across a fixed resistor in series with the sensor resistordetermines the voltage signal at the PCM This voltage signal is equal to the reference voltage

minus the voltage drop across the fixed resistor

The EOT sensor measures the temperature of the engine oil The sensor is typically threaded intothe engine oil lubrication system The PCM uses the EOT sensor input in conjunction with otherPCM inputs to determine oil degradation

The PCM uses EOT sensor input to initiate a soft engine shutdown to prevent engine damage

from occurring as a result of high oil temperatures Whenever engine RPM exceeds a calibratedlevel for a certain period of time, the PCM begins reducing power by disabling engine cylinders

On VCT applications, the PCM uses the EOT sensor input to adjust the VCT control gains andlogic for camshaft timing

Typical EOT Sensor

Evaporative Emission (EVAP) Canister Purge Valve

The EVAP canister purge valve is part of the enhanced EVAP system controlled by the PCM Thisvalve controls the flow of vapors (purging) from the EVAP canister to the intake manifold duringvarious engine operating modes The EVAP canister purge valve is a normally closed valve TheEVAP canister purge valve controls the flow of vapors by way of a solenoid, eliminating the needfor an electronic vacuum regulator and vacuum diaphragm For E-Series, Escape/Mariner,

Expedition, F-Series, Fiesta, Fusion 2.5L, Fusion 3.0L, Milan and Navigator, the PCM outputs aduty cycle between 0% and 100% to control the EVAP canister purge valve For all others, the

PCM outputs a variable current between 0 and 1,000 mA to control the EVAP canister purge

valve

Typical EVAP Canister Purge Valve

Part

1 — Fuel Vapor to EVAP

Canis-ter

2 — Fuel Vapor to Intake

Mani-fold

Evaporative Emission (EVAP) Canister Purge Check Valve

The EVAP canister purge check valve is used on turbocharged engines to prevent boost pressurefrom forcing open the EVAP canister purge valve and entering the EVAP system The valve is

open under normal engine vacuum The valve closes during boost conditions to prevent the fueltank from being pressurized and hydrocarbons forced out of the EVAP system into the atmospherethrough the EVAP canister vent valve When the engine is off, or at atmospheric pressure, the

EVAP canister purge check valve is in an indeterminate state The EVAP canister purge check

valve is an integral part of the purge valve assembly

Typical EVAP Canister Purge Check Valve

Check Valve

Evaporative Emission (EVAP) Natural Vacuum Leak Detection (NVLD) Module

The NVLD module is located in the EVAP canister vent hose, under the vehicle Battery voltage(VBAT) is supplied to the NVLD module to allow EVAP system diagnostics to run after the ignition

is turned OFF The NVLD module electrical connector also incorporates a communication (NVLD)circuit and a ground (GND) circuit between the NVLD module and the powertrain control module(PCM)

Internal to the NVLD module is a normally open vacuum switch (closes with vacuum), a normallyclosed vacuum relief valve (opens with excessive vacuum), a normally closed pressure relief valve(opens during refueling), an internal ambient air temperature sensor and a timer The NVLD

module completes a series of checks to confirm the integrity of the enhanced EVAP system

components in the engine running state and the ignition OFF state When the ignition is turned ONand the engine is running the NVLD module sends the information stored during the ignition OFFtests to the PCM

EVAP NVLD Module

Part

3 — Electrical Connector

Exhaust Gas Recirculation (EGR) Orifice Tube Assembly

The EGR orifice tube assembly is a section of tubing connecting the exhaust system to the intakemanifold The assembly provides the flow path for the EGR to the intake manifold and also

contains the metering orifice and 2 pressure pick-up tubes The internal metering orifice creates ameasurable pressure drop across it as the EGR valve opens and closes This pressure differentialacross the orifice is picked up by the differential pressure feedback EGR sensor which providesfeedback to the PCM

EGR Orifice Tube Assembly

Exhaust Gas Recirculation (EGR) System Module (ESM)

The ESM is an integrated differential pressure feedback EGR system that functions in the samemanner as a conventional differential pressure feedback EGR system The various system

components have been integrated into a single component called the ESM The flange of the valveportion of the ESM bolts directly to the intake manifold with a metal gasket that forms the meteringorifice This arrangement increases system reliability, response time, and system precision By

relocating the EGR orifice from the exhaust to the intake side of the EGR valve, the downstreampressure signal measures manifold absolute pressure (MAP) This MAP signal is used for EGRcorrection and inferred barometric pressure (BARO) at ignition on The system provides the PCMwith a differential pressure feedback EGR signal that is identical to a traditional differential

pressure feedback EGR system

Part

2 — Upstream Differential

Pres-sure Feedback EGR Port

3 — Differential Pressure

Feed-back EGR and MAP Sensor

4 — EGR Vacuum Regulator

In-tegrated into Upper Body

5 — Downstream Differential

Pressure Feedback EGRPort

6 — To Intake Manifold Plenum

Exhaust Gas Recirculation (EGR) Vacuum Regulator Solenoid

The EGR vacuum regulator solenoid is an electromagnetic device used to regulate the vacuumsupply to the EGR valve The solenoid contains a coil which magnetically controls the position of adisc to regulate the vacuum As the duty cycle to the coil increases, the vacuum signal passed

through the solenoid to the EGR valve also increases Vacuum not directed to the EGR valve isvented through the solenoid vent to the atmosphere At 0% duty cycle (no electrical signal

applied), the EGR vacuum regulator solenoid allows some vacuum to pass, but not enough to

open the EGR valve

EGR Vacuum Regulator Solenoid

EGR VACUUM REGULATOR SOLENOID DATA

EGR vacuum regulator resistance: 26-40 Ohms

Exhaust Gas Recirculation (EGR) Valve

The EGR valve in the differential pressure feedback EGR system is a conventional,

vacuum-actuated valve The valve increases or decreases the EGR flow As vacuum applied tothe EGR valve diaphragm overcomes the spring force, the valve begins to open As the vacuumsignal weakens, at 5.4 kPa (1.6 in-Hg) or less, the spring force closes the valve The EGR valve isfully open at approximately 15 kPa (4.4 in-Hg)

Since EGR flow requirement varies greatly, providing repair specifications on flow rate is

impractical The on board diagnostic (OBD) system monitors the EGR valve function and triggers aDTC if the test criteria is not met The EGR valve flow rate is not measured directly as part of thediagnostic procedures

Typical EGR Valve

Part

1 — Vacuum Connection from

EGR Vacuum Regulator lenoid

So-2 — Intake Manifold Connector

3 — Orifice Tube Connection