Ford EEC IV

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Ford EEC IV

• Operation and Testing

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Overview
A/F Mixture Ignition Timing Idle Speed Thermactor
Airflow Canister Purge EGR Flow TCC AC Fan WOT
Cut Off Inlet Air Temp Fuel Pump Relay Turbo
Boost

• ECT
• MAP/BARO
• TPS
• CKP/CMP
• O2S
• EGR Position
• ACT
• KS
• BOO
• AC
• Power Steering

PCM
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Operating Modes

• Base Engine Strategy
• MPG Lean Cruise
• Modulator Strategy
• Limited Operational Strategy
• Adaptive Strategy

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Base Engine Strategy

• Used to control warm engine running
• Open Loop starts at 130o
• Warm up mode sub modes
• Cranking
• Closed-throttle
• Part throttle (closed loop)
• Wide-open throttle (WOT)
• PCM controls actuators for good driveability

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MPG Lean Cruise

• Some engines beginning 1988
• Certain criteria are met
• Goes out of closed-loop fuel control
• Very lean for economy at cruise

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Modulator Strategy

• Conditions that require significant change from
  Base Engine Strategy
• Cold engine
• Overheated engine
• High altitude

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Limited Operational Strategy

• Component Failure
• Protect other components
• Converter
• Substitute values from another sensor
• MAP TPS
• ECT IAT
• EGR Disable EGR

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Adaptive Strategy

• Started in 1985
• PCM has base map
• Monitors operation and modifies base map
• Compensates for wear etc.
• Dirty Injectors
• Are in response to O2S
• Stored in KAM

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Adaptive Strategy
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Adaptive Strategy
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Adaptive Strategy
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Adaptive Strategy
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Inputs
A/F Mixture Ignition Timing Idle Speed Thermactor
Airflow Canister Purge EGR Flow TCC AC Fan WOT
Cut Off Inlet Air Temp Fuel Pump Relay Turbo
Boost

• ECT
• MAP/BARO
• TPS
• CKP/CMP
• O2S
• EGR Position
• ACT
• KS
• BOO
• AC
• Power Steering

PCM
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Engine Coolant Temp

• Thermistor
• Voltage to PCM is 4.5 cold to .3 hot
• Resistance 470K? cold to 1k? hot
• Influences PCMs calibrations for
• A/F Raito
• Idle Speed
• Thermactor Air
• Canister Purge
• Choke Voltage, Temp compensated accel pump
• Upshift light

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Pressure Sensors

• MAP, BARO
• Pressure-sensitive capacitor
• Convert to frequency out
• 100 Hz no load Idle
• 159 Hz atmospheric (WOT)
• Voltage will go from 0 to 5 at the frequency
  above

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Pressure Sensors

• MAP used for BARO
• PCM uses Key On before cranking and WOT for BARO
  calculations.
• BARO used with Vane Airflow Sensors
• Looks like MAP with collar

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Throttle Position Sensor

• Some adjustable, some not
• Potentiometer
• 3 wires, 5v reference, ground, signal
• Two common problems
• Bad spot, signal dropout
• Bad ground
• Full reference on signal
• Biased high

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Profile Ignition Pickup (PIP)

• Hall Effect Switch
• Engine speed and crank position
• In distributor
• One vane narrower for location

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Profile Ignition Pickup (PIP)

• On DIS sensor is on front of engine
• One vane for each pair of companion cylinders
• Most PIP signals go from .4v or less to battery
  voltage at 10o BTDC

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Cylinder Identification (CID)

• Used with Distributorless Ignition
• PIP doesn't know which stroke
• Driven at cam speed
• Also usedfor SFI

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4 Cylinder PIP CID

• On DIS, 1 4 fire together
• CID is on crank with PIP

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Ignition Diagnostic Monitor

• Used on TFI systems
• Checks to see that spark occurred
• Wire with 22k? from Tach wire to PCM
• Makes sure SPOUT command is carried out
• Makes sure timing advance is working

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Knock Sensor (KS)

• Piezoelectric type
• Vibration sends signal to PCM
• PCM retards timing 1/2o per engine revolution

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Intake Air Temp Sensor (IAT)

• Was called Air Charge Temp (ACT) before OBDII
• Thermistor
• Voltages and resistance same as ECT
• A/F and advance
• Used on most Fords

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EGR Position (EVP)Feedback (PFE)

• EVP Linear Potentiometer
• only monitors position
• EVP Black and White physically interchangeable
• PFE is like MAP but gives a voltage
• Measures exhaust pressure under EGR valve
• PFE measures flow used to
• Fine tune EGR position
• Fine tune A/F ratio
• Modify ignition timing

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Vane Air Flow (VAF)

• Used with VAT and BP to calculate Speed Density

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Mass Airflow MAF

• Beginning in 1988
• Uses sample tube
• Uses hot wire
• Encased in Glass
• 200o above ambient
• A/F and Timing

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Transmission Switches

• PCM knows if in gear, park or neutral
• Affects Idle air control strategy
• For A/T because converter loads engine
• Response to rapid throttle closing

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Transmission Switches

• AXOD uses 3 switches
• Neutral Pressure NPS
• Trans Hydraulic THS 3-2
• Trans Hydraulic THS 4-3
• AXOD Trans Temp TTS opens over 275oF
• Will apply TCC if temps get high like uphill climb

Can tell which gear except if it is in 1 or 2
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Transmission Switches
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Transmission Switches

• Manual Trans
• Neutral Gear Switch NGS
• Clutch Engaged Switch CES
• Wired in parallel so both must be open for PCM to
  know car is in gear.

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Brake On/Off BOO

• In stop lamp switch
• A4LD has PCM controlled converter lockup
• Used on most models today
• Increases idle when in gear and brakes are on
• May disengage AC on prolonged idle

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Vehicle Speed Sensor (VSS)

• Speedometer output
• Mechanical or electric speedometer.
• 8 cycles per revolution
• 128000 signals per mile
• Used for
• TCC lockup
• Coolant fan control
• Identify deceleration

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Other Inputs

• Power Steering Pressure Switch PSPS
• Opens between 400 and 600 PSI
• Increases idle speed
• AC Demand (ACD)
• AC Clutch Cycling Switch (ACCS)
• PCM watches to increase idle speed

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Outputs
A/F Mixture Ignition Timing Idle Speed Thermactor
Airflow Canister Purge EGR Flow TCC AC Fan WOT
Cut Off Inlet Air Temp Fuel Pump Relay Turbo
Boost

• ECT
• MAP/BARO
• TPS
• CKP/CMP
• O2S
• EGR Position
• ACT
• KS
• BOO
• AC
• Power Steering

PCM
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Air / Fuel Mixture Control

• Three types
• Feedback Carburetors
• Central Fuel Injection (TBI)
• Electronic Fuel Injection (PFI)
• Non Sequential
• Group
• Sequential

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Feedback Carburetors

• Motorcraft Carter uses solenoid to bleed air
  into idle and main metering circuits

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Holley Carburetors

• Holley uses remote solenoid with similar idle
  control

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Holley Carburetors

• Uses vacuum diaphragm and valve for main metering
  control

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Central Fuel Injection

• Low Pressure System
• Single injector
• Low Pressure System
• Two injectors
• Alternates injectors
• ECM grounds to turn on
• Pulse Width Modulated

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Central Fuel Injection
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CFI Fuel Delivery
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Port Fuel Injection (EFI)
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Port Fuel Injection

• Non-sequential (EFI)
• Group or bank-to-bank
• Two Groups
• Sequential (SEFI)
• Injectors pulsed one at a time in firing order
• Used throughout product line by early 1990s

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Injector Removal
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Fuel Supply System
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Fuel Supply System

• Fuel Pump
• In tank
• Trucks may have a lift and pressure pump
• Most are around 39 psi
• Pressure relief at 100 psi

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Fuel Supply System

• Pressure regulator
• Manifold pressure modified
• Low of 30 around psi (deceleration)
• High of 39 psi (WOT)
• Turbocharged may go as high as 50 psi
• CFI does not use manifold pressure.
• High pressure 38-40 psi
• Low pressure 14.5 psi

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Fuel Supply System

• Fuel Pump Relay PCM Controlled
• Turns on with key for 1-2 seconds or until PIP
  signal is present.
• Inertia Switch is in series with pump

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Thick Film Integrated (TFI-IV)

• Thick film refers to the type of semi-conductor
• Controls spark primary
• Sends PIP to PCM
• PCM modifies and sends back SPOUT
• SPOUT tells TFI when to turn primary on and off.
• In distributor or Closed Bowl

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Thick Film Integrated (TFI-IV)
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Thick Film Integrated (TFI-IV)
Closed Bowl
TFI Module
Octane rod can change base timing while keeping
rotor right.
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Distributorless Ignition

• PCM controls dwell and timing
• DIS module is like TFI module
• Also uses SPOUT
• Now called Spark Angle Word (SAW)
• 1991 second generation using Reluctance instead
  of Hall sensors
• 35 teeth on crank 36 minus1 for position

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Distributorless Ignition

• Base Timing Check
• Remove SPOUT/SAW jumper
• 10o
• Self check adds 20o
• Octane adjustment jumper looks like SPOUT
• Retards 3o to 4o and can be left out

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Spout Connectors
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Idle Speed

• Carbs CFI use
• Throttle kicker
• DC motor idle speed control (ISC)
• Idle Tracking Switch
• Senses closed throttle
• PCM then operates ISC
• Act as Idle Dashpot

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EFI Idle Speed Control

• Air bypass solenoid
• PCM Controlled
• Duty Cycle pintle valve
• Also a dashpot

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Thermactor Air Management

• Thermactor Air Bypass (TAB)
• Thermactor Air Diverter (TAD)
• PCM Controlled

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Thermactor Air Management

• CTS Below 50o TAB grounded
• Sends air to atmosphere
• Between 50 and 190 Bypass valve sends air to
  diverter and to manifold
• Over 190 closed loop and air goes to Cat
• Bypass at idle, WOT, and with failing O2S

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Open Loop Tip

• The fastest way to see if vehicle is in open loop
  is to see where the air is going
• Cat Closed Loop
• Atmosphere or manifold Closed Loop
• Provided thermactor system is working

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Canister Purge

• Three types
• Constant purge with no PCM control
• PCM controlled in-line solenoid
• PCM controlled with temperature controlled vacuum
  valve

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Canister Purge/Heat Control
To valve that warms intake manifold
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EGR Control

• EGR Control and EGR Vent
• 2 solenoids that are dithered

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EGR Control

• EGR Shutoff Solenoid
• Uses one solenoid
• Controls ported vacuum
• EGR Shutoff Solenoid with Backpressure Transducer
• One solenoid
• Strength of vacuum controlled by transducer
• Does not have EVP sensor

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EGR Control

• Vacuum Regulator
• Introduced in 1985 and is used for most
  applications

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EEC IV Diagnosis

• Codes follow self test
• Codes can be read
• Manually
• Watch MIL
• Hook up meter
• Star II
• Other scan tool

Notice the safety glasses ?
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Slow and Fast Codes

• Slow codes can be read with pulsing meter or MIL
• Fast codes can be read by scan tool
• Fast codes precede slow and look like a momentary
  flashing.

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Diagnostic Connector
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KOEO Self Test Procedures

• Engine warm
• Turn off for 10 seconds
• KOEO, then ground STI
• Test will run, then read codes
• All accessories off
• 2.5L and 4.9L hold clutch fully in.

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KOEO Self Test Codes
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KOER Self Test Procedures

• Engine warm 2000 RPM 2 min
• Turn off for 10 seconds
• KOER, then ground STI
• Test will run, then read ID codes
• Push brake and turn steering wheel
• After code 10 (or 1 flash) snap WOT

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KOER Self Test Codes
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Computed Timing

• Pull SPOUT/SAW
• Check for 10o with timing light
• Reinstall SPOUT/SAW
• Run KOER self test
• At end of last code, 20o will be added to base
  timing for 2 min.

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Other Tests

• Continuous monitor (wiggle)
• After last code, deactivate and reactivate self
  test
• Wiggle wires etc. Fault will display
• SEFI Cylinder Balance
• KOER after last code, tip throttle and release.

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