Ford EEC IV Operation and Testing

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

Operating Modes Base Engine Strategy MPG Lean Cruise Modulator Strategy Limited Operational Strategy Adaptive Strategy

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

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

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

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

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

Adaptive Strategy

Adaptive Strategy

Adaptive Strategy

Adaptive Strategy

Inputs A/F Mixture Ignition Timing ECT Idle Speed MAP/BARO TPS 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

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

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

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

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

Profile Ignition Pickup (PIP) Hall Effect Switch Engine speed and crank position In distributor One vane narrower for location

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

Cylinder Identification (CID) Used with Distributorless Ignition PIP doesn't know which stroke Driven at cam speed Also used for SFI

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

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

Knock Sensor (KS) Piezoelectric type Vibration sends signal to PCM PCM retards timing 1/2o per engine revolution

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

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

Vane Air Flow (VAF) Used with VAT and BP to calculate Speed Density

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

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

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

Transmission Switches

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.

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

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

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

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

Air / Fuel Mixture Control Three types Feedback Carburetors Central Fuel Injection (TBI) Electronic Fuel Injection (PFI) Non Sequential Group Sequential

Feedback Carburetors Motorcraft & Carter uses solenoid to bleed air into idle and main metering circuits

Holley Carburetors Holley uses remote solenoid with similar idle control

Holley Carburetors Uses vacuum diaphragm and valve for main metering control

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

Central Fuel Injection

CFI Fuel Delivery

Port Fuel Injection (EFI)

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

Injector Removal

Fuel Supply System

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

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

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

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”

Thick Film Integrated (TFI-IV)

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

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

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

Spout Connectors

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

EFI Idle Speed Control Air bypass solenoid PCM Controlled Duty Cycle pintle valve Also a dashpot

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

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

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

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

Canister Purge/Heat Control To valve that warms intake manifold

EGR Control EGR Control and EGR Vent 2 solenoids that are “dithered”

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

EGR Control Vacuum Regulator Introduced in 1985 and is used for most applications

Notice the safety glasses  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 

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.

Diagnostic Connector

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.

KOEO Self Test Codes

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

KOER Self Test Codes

Computed Timing Pull SPOUT/SAW Reinstall SPOUT/SAW Run KOER self test 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.

Other Tests Continuous monitor (wiggle) SEFI Cylinder Balance 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.