ford eec iv

Ford EEC IV

Operation and Testing

Overview

ECTMAP/BAROTPSCKP/CMPO2SEGR PositionACTKSBOOACPower Steering

PCM

A/F MixtureIgnition Timing

Idle SpeedThermactor Airflow

Canister PurgeEGR Flow

TCCAC Fan

WOT Cut OffInlet Air Temp

Fuel Pump RelayTurbo Boost

Operating Modes

Base Engine Strategy

MPG Lean Cruise

Modulator Strategy

Limited Operational Strategy

Adaptive Strategy

Base Engine Strategy

Used to control warm engine runningOpen Loop starts at 130o

Warm up mode sub modesCrankingClosed-throttlePart 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 StrategyCold engineOverheated engineHigh altitude

Limited Operational Strategy

Component Failure

Protect other componentsConverter

Substitute values from another sensorMAP TPSECT IATEGR Disable EGR

Adaptive Strategy

Started in 1985PCM has base mapMonitors operation and modifies base mapCompensates for wear etc.Dirty Injectors

Are in response to O2SStored in KAM

Adaptive Strategy

Adaptive Strategy

Adaptive Strategy

Adaptive Strategy

Inputs

ECTMAP/BAROTPSCKP/CMPO2SEGR PositionACTKSBOOACPower Steering

PCM

A/F MixtureIgnition Timing

Idle SpeedThermactor Airflow

Canister PurgeEGR Flow

TCCAC Fan

WOT Cut OffInlet Air Temp

Fuel Pump RelayTurbo Boost

Engine Coolant TempThermistorVoltage to PCM is 4.5 cold to .3 hotResistance 470K cold to 1k hotInfluences 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 out100 Hz no load Idle159 Hz atmospheric (WOT)

Voltage will go from 0 to 5 at the frequency above

Pressure SensorsMAP used for BAROPCM 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 notPotentiometer3 wires, 5v reference, ground, signalTwo common problemsBad spot, signal dropoutBad ground

Full reference on signalBiased 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 usedfor SFI

4 Cylinder PIP CIDOn 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 interchangeablePFE 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 strategyFor A/T because converter loads engine

Response to rapid throttle closing

Transmission Switches

AXOD uses 3 switchesNeutral Pressure NPSTrans Hydraulic THS 3-2Trans Hydraulic THS 4-3

AXOD Trans Temp TTS opens over 275oFWill 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 TransNeutral Gear Switch NGSClutch Engaged Switch CESWired 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 revolution128000 signals per mileUsed for TCC lockup Coolant fan control Identify deceleration

Other Inputs

Power Steering Pressure Switch PSPSOpens between 400 and 600 PSI Increases idle speed

AC Demand (ACD)

AC Clutch Cycling Switch (ACCS)PCM watches to increase idle speed

Outputs

ECTMAP/BAROTPSCKP/CMPO2SEGR PositionACTKSBOOACPower Steering

PCM

A/F MixtureIgnition Timing

Idle SpeedThermactor Airflow

Canister PurgeEGR Flow

TCCAC Fan

WOT Cut OffInlet Air Temp

Fuel Pump RelayTurbo Boost

Air / Fuel Mixture Control

Three typesFeedback CarburetorsCentral Fuel Injection (TBI)Electronic Fuel Injection (PFI)

Non SequentialGroupSequential

Feedback CarburetorsMotorcraft & 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 SystemSingle injector

Low Pressure SystemTwo injectorsAlternates 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-bankTwo Groups

Sequential (SEFI) Injectors pulsed one at a time in firing orderUsed throughout product line by early

1990s

Injector Removal

Fuel Supply System

Fuel Supply System

Fuel Pump In tankTrucks may have a lift and pressure pumpMost are around 39 psiPressure relief at 100 psi

Fuel Supply System

Pressure regulatorManifold pressure modifiedLow of 30 around psi (deceleration)High of 39 psi (WOT)Turbocharged may go as high as 50 psiCFI does not use manifold pressure.

High pressure 38-40 psiLow pressure 14.5 psi

Fuel Supply SystemFuel 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-conductorControls spark primarySends PIP to PCMPCM modifies and sends back SPOUTSPOUT tells TFI when to turn primary on and off.In distributor or “Closed Bowl”

Thick Film Integrated (TFI-IV)

Thick Film Integrated (TFI-IV)

Closed BowlTFI Module

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 CheckRemove SPOUT/SAW jumper10o 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 Throttle kickerDC 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 solenoidPCM 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 groundedSends air to atmosphere

Between 50 and 190 Bypass valve sends air to diverter and to manifoldOver 190 closed loop and air goes to CatBypass 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 PurgeThree 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

EEC IV Diagnosis

Codes follow self test

Codes can be read Manually

Watch MILHook up meter

Star IIOther 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/SAWCheck for 10o with timing light

Reinstall SPOUT/SAW

Run KOER self testAt end of last code, 20o will be added to

base timing for 2 min.

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.