Calif 5.0l Cfi Eec-Iii Lincoln Continental VII

DESCRIPTION

Note. To identify EEC System, EEC-III has ignition module mounted to fender apron. The EEC-IV has ignition module mounted on distributor housing.

The EEC system consists of an Electronic Control Assembly (ECA), several sensors located on the engine or in the various engine systems, special actuators governed by the ECA, and various connecting electrical and vacuum lines. This system adjusts the engine to the best settings for various conditions of load, speed, temperature and altitude by controlling the following functions

1. Ignition Timing
2. Air/Fuel Ratio
3. Engine Speed At Idle
4. Exhaust Gas Recirculation (EGR) Flow Rate
5. Secondary (Thermactor) Air Flow Rate
6. Fuel Evaporation Canister Purging

EEC-III Component Locations. Scheme 62

ELECTRONIC CONTROL ASSEMBLY (ECA)

The ECA is a solid-state, micro-computer consisting of a processor assembly and a calibration assembly. This unit is located in the passenger compartment under the instrument panel, to the left of the steering column. The ECA is the "brain" of the EEC system.

Processor Assembly

The processor assembly is housed in an aluminum case and contains circuits designed to

1. Continuously sample input signals from the sensors.
2. Calculate the proper spark advance, air/fuel ratio, EGR flow and thermactor air flow.
3. Send out control signals to adjust spark timing, air/fuel ratio, EGR flow, thermactor air mode, evaporation canister purge and idle speed.

The processor assembly also provides a continuous reference voltage of 9.0 volts to the sensors.

Calibration Assembly

The calibration assembly is contained in a black plastic housing which is attached to the top of the processor assembly. It contains the "memory" and programming used by the processor assembly. The calibration assembly is capable of

1. Providing operating information for that particular vehicle, for use by the processor assembly.
2. Recalling information from its memory when required.

Power Relay

Activated by the ignition switch to supply battery voltage to the EEC. Relay is mounted to lower right side of ECA mounting bracket. Also protects ECA from possible damage due to reversed voltage polarity.

EEC Electronic Control Assembly (ECA). Scheme 63

LIMITED OPERATION STRATEGY (LOS) MODE

The LOS mode functions during engine start, or upon failure of the ECA detected by a "safeguard" circuit in the ECA. This mode allows continued vehicle operation (with reduced performance) until repairs can be made. In this mode the actuator functions are set as follows

1. Ignition Module Timing; Minimum spark advance (10° BTDC).
2. Exhaust Gas Recirculation (EGR): No EGR.
3. Thermactor Air (TAB): By-pass (dump) position.
4. Canister Purge (CANP): Canister sealed, no purge.
5. Throttle Kicker (TK): Low RPM idle.

Engine Coolant Temperature (ECT) Sensor

Installed in heater outlet fitting at front of intake manifold near right valve cover, the ECT sensor converts coolant temperature to an electrical signal for the ECA. The brass sensor housing contains a thermistor (resistor that changes value according to temperature). The ECA determines engine coolant temperature by the resistance value of the sensor.

Throttle Position (TP) Sensor

The TP sensor is a potentiometer. The resistance of the sensor varies with throttle opening. The ECA applies a reference voltage to the sensor and the resultant sensor output voltage allows the ECA to determine throttle position (closed throttle, part throttle or wide open throttle). This information is used by the ECA in determining the proper amount of spark advance, EGR flow, air/fuel ratio and the proper thermactor air mode.

Note. The throttle position (TP) sensor mounting holes are slotted to permit rotational adjustment. If sensor is replaced, it must be correctly positioned or misleading throttle information will be sent to the ECA.

Crankshaft Position (CP) Sensor

To provide the EEC system with an accurate timing reference (when pistons reach 10° BTDC), the crankshaft vibration damper is fitted with a 4-lobe "pulse ring".

As the crankshaft rotates, the pulse ring interrupts a magnetic field at the tip of the CP sensor (mounted on right front of engine). When the field is interrupted, an output signal is generated and sent to the ECA.

The ECA uses these signals to determine the exact position of the crankshaft. From the pulse frequency, the ECA can determine engine RPM. By knowing these two factors, the ECA can determine amount of ignition timing advance required for best engine operation.

Note. Once the CP sensor is installed, no field adjustment is necessary.

Oxygen Sensor

Installed in the exhaust manifold, the oxygen sensor provides the ECA with the oxygen concentration of the exhaust gas.

The oxygen sensor monitors the oxygen concentration of the exhaust gas and generates an output of .6 to 1.1 volts when detecting a rich exhaust gas mixture, and less than .2 volts when detecting a lean mixture. The constantly changing voltage signal is sent to the ECA for analysis.

Barometric and Manifold Absolute Pressure (BMAP) Sensor

The BMAP sensor is actually 2 sensors combined into 1 assembly. It monitors the absolute value of the intake manifold pressure and atmospheric pressure.

Changes in atmospheric pressure and intake manifold pressure are converted into electrical signals and sent to the ECA. The signals are used to adjust spark advance and EGR rate to fit engine conditions.

Note. Manifold absolute pressure is the difference between barometric pressure and manifold pressure.

Air Charge Temperature (ACT) Sensor

The ACT sensor provides the ECA with air temperature readings which allow the computer to compensate for air density variations.

EGR Valve Position (EVP) Sensor

The EVP sensor is attached to the EGR valve and provides an electrical signal to the ECA that indicates EGR valve position. Using the input from this and other sensors, the ECA can regulate EGR flow by activating or deactivating a pair of solenoid valves.

THROTTLE KICKER SYSTEM

The throttle kicker system consists of a Throttle Kicker Solenoid (TKS) and a Throttle Kicker Actuator (TKA). The system is designed to increase engine RPM when the A/C is on, at high altitude, and when coolant temperature is above or below a specific range.

With A/C "ON", the ECA energizes the TKS, allowing intake manifold vacuum to reach the TKA. The TKA is positioned on the throttle body against the throttle lever. With vacuum applied, the TKA will increase engine RPM for increased cooling and smoother idle. The TKA is also energized during engine warm-up or if an engine overheat condition exists.

EXHAUST GAS RECIRCULATION (EGR) SYSTEM

The EGR system used with EEC-III has 3 major components: an EGR valve and sensor assembly, an EGR cooler, and a 2-solenoid EGR control assembly.

Utilizing engine manifold vacuum to operate the EGR valve, the ECA controls EGR gas flow. When EGR valve is open, exhaust gas from exhaust manifold is directed into the intake manifold and becomes part of the combustion cycle, helping to reduce NOx emission levels.

EGR Valve and Sensor Assembly

The EGR valve is mounted to the intake manifold under the throttle body. The valve controls EGR flow through a pintle valve and seat. An EGR valve position sensor (EVP) is attached to the valve and provides an electrical signal to the ECA indicating EGR valve position.

Electronic Engine Control Sensors. Scheme 64

The EGR valve, unlike standard EGR valves, has no opening to observe pintle valve movement. The EGR valve and position sensor are serviced as individual units.

Dual EGR Control Solenoids

EGR valve flow rate is controlled by two solenoid valves mounted on the left valve cover. Proper control of vacuum needed to operate the EGR valve requires two types of solenoid valves

1. A vent valve, which is normally open; that is, the outlet port is normally connected to the inlet port when the solenoid is not energized.
2. A vacuum valve, which is normally open; that is, the outlet port is normally blocked when solenoid is not energized.

Utilizing input from the various sensors, the ECA directs the vacuum and vent solenoids to: (1) Increase EGR flow by applying vacuum to the EGR valve, (2) Maintain the EGR flow by trapping vacuum in the system, and (3) Decrease EGR flow by venting the system to the atmosphere.

EGR Cooler Assembly

An EGR gas cooler is used to reduce EGR gas temperature, thus providing improved flow characteristics, better engine operation and EGR valve durability.

Dual EGR Control Solenoids. Scheme 65

THERMACTOR AIR SYSTEM

The Thermactor Air System used with EEC-III consists of the following components: an air supply pump, Thermactor By-pass/Diverter valve, dual Thermactor solenoids, 2 check valves, and a 3-way converter (referred to as COC/TWC).

The efficiency of the catalytic converter is dependent upon temperature and the chemical makeup of the exhaust gases. Air must be provided to the COC catalyst for the oxidation of HC and CO by-products of the TWC catalyst.

Air Supply Pump

This belt driven pump provides the source of air to be controlled by the by-pass/diverter valve as directed by the ECA. The air pump does not have a pressure relief valve, this function being controlled by the by-pass/diverter valve.

By-Pass/Diverter Valve

Air from the air pump has three possible routes through the by-pass/diverter valve

1. Downstream air (air injected into three-way catalyst).
2. Upstream air (air injected into exhaust manifold).
3. By-pass (air by-passed to atmosphere).

The proper routing for thermactor air is determined by the ECA based on engine coolant temperature versus time curve and other sensor data. During normal coolant temperature operation, the air is normally directed downstream.

The air is by-passed when the closed throttle time exceeds a preset time value, or if the time between the Exhaust Gas Oxygen lean/rich sensor exceeds a set time value. The air will also be by-passed during wide open throttle mode or during extended closed throttle operation.

During engine warm-up the thermactor air will be routed upstream. This is to help remove excessive amounts of HC and CO produced during the warm-up period.

Thermactor Air System By-Pass/Diverter Valve. Scheme 66

Dual Air Control Solenoids

The by-pass/diverter valve operation is controlled by two solenoid valves: Thermactor Air By-Pass (TAB) valve, and Thermactor Air Diverter (TAD) valve. The valves are mounted on top of the right fender apron.

The TAB solenoid valve controls manifold vacuum to the by-pass portion of the by-pass/diverter valve, which in turn controls whether air from thermactor pump is by-passed to the atmosphere (solenoid de-energized) or routed to control the diverter valve (solenoid energized).

The TAD solenoid valve controls manifold vacuum to the diverter portion of the by-pass/diverter valve, which in turn controls which direction (upstream or downstream) thermactor air is routed. When de-energized, air is routed downstream. When energized, air is routed upstream.

Exhaust Check Valve

Two exhaust check valves are used in the EEC III Thermactor system to prevent reverse flow of exhaust gases in the event of system malfunction. One check valve is located between the by-pass/diverter valve and the exhaust port drillings, and the other valve between the catalytic converter and the by-pass/diverter valve.

Three-Way Catalytic Converter (COC/TWC)

This is a dual catalytic converter consisting of two converters in one shell, with a mixing chamber between the two. Each converter is composed of a ceramic "honey-comb" coated with catalyst material.

The front, or "three-way catalyst" (TWC) converter acts on exhaust gases as they arrive from the engine. As gases flow from the TWC converter to the rear, or "conventional oxidation catalyst" (COC) converter, they mix with air from the thermactor pump injected into the mixing chamber. This air is required for proper oxidation of HC and CO in the COC converter.

Canister Purge (CANP) Solenoid

This solenoid is a combination solenoid and valve. Located in the line between the intake manifold purge fitting and the carbon canister, the CANP solenoid controls the flow of vapors from the canister to the intake manifold during various engine operating modes. The valve is opened and closed by a signal from the ECA.

DURA-SPARK III IGNITION SYSTEM

The EEC-III system uses a Dura-Spark III module (Brown grommet where wires emerge) and a Dura-Spark II ignition coil. A resistance wire is also used in the primary circuit.

Distributor

The EEC distributor eliminates conventional mechanical and vacuum advance mechanisms. All timing is controlled by the ECA, which is capable of firing the spark plug at any point within a 50° range depending on calibration. This increased spark capability requires greater separation of adjacent distributor cap electrodes to prevent cross-fire.

EEC III Ignition Distributor Assembly. Scheme 67

TESTING

Note. Due to the complexity of the EEC III system, full testing cannot be done unless an EEC III tester (T79L-50-EEC-II or T80L-50-EEC-II , and T78L-50-DVOM or T79L-50-DVOM ) is used. Instructions for testing come with the tester, which is available from Owatonna Tool Co. However, some checks can be made using regular shop equipment. These checks are outlined in the following procedures.

TESTING NOTES & CAUTIONS

Note. No repairs or adjustments can be made to the ECA components. If diagnosis shows Processor or Calibration units are not functioning properly, they must be replaced.

BASIC EEC TROUBLE SHOOTING

1. Perform basic fuel system and ignition system checks, to ensure there is gas and spark.
2. Remove air cleaner assembly and inspect all vacuum and pressure hoses for proper connection to fittings, or any broken, cracked or pinched conditions.
3. Inspect EEC sub-system harness for proper connections to EGR solenoid valves. Red wire to both, Yellow wire to vacuum solenoid and Green wire to vent solenoid.
4. Check for any loose or detached connectors or broken or detached wires. Ensure all terminals are completely seated.
5. Repair items as required and replace air cleaner.
6. Check battery charge, cable connections and main electrical wiring.
7. Test resistance of all sensors and solenoids, using values given in COMPONENT RESISTANCE VALUES Chart. Be sure to disconnect component from circuit before checking resistance.

SELF-TEST PROCEDURES

Perform a visual check of all computer related wiring and connectors. Ensure all electrical, tune-up, fuel system and other basic engine operations are completed or in good working order before checking the EEC-III system. If any trouble codes are found in EEC-III computer memory, refer to the EEC-III DIAGNOSTIC CODES CHART . If necessary, use appropriate test equipment and an electrical diagram to check each circuit indicated. Use the following procedures to trigger self-test operation for all Ford models with EEC-III.

1. Start engine and run at 1800 RPM until upper radiator hose is hot. Connect a vacuum pump to B/MAP vent port.
2. Connect an analog meter positive lead to TAD solenoid (Circuit No. 99). Ground negative voltmeter lead. Apply 20" Hg vacuum to B/MAP and hold for 8 to 60 seconds. Release vacuum.
3. As vacuum is released, throttle kicker solenoid will extend and retract. Voltmeter needle will also pulse 2 times (on EFI engines) or 4 times (on carburetor engines).
4. Throttle kicker will extend and computer will begin self-test diagnosis. After a certain amount of time, throttle kicker will retract. This action indicates the end of self-test mode and computer will transmit a pulsing code to voltmeter.
5. If any trouble codes are present, voltmeter needle will begin pulsing. The 2 digit codes are obtained by counting pulses of needle similar to how the EEC-IV does. Record all codes.

EEC-III DIAGNOSTIC CODES CHART

Removal

Disconnect wiring harness from BMAP sensor. Disconnect vacuum hose, remove retaining nuts, and remove sensor.

Installation

Position sensor and tighten retaining nuts. Connect vacuum hose to "Manifold" port. DO NOT connect any hose to "Vent" port. Connect wiring harness.

Remove air cleaner. Disconnect 2-wire connector and 2 vacuum hoses from solenoid. Remove valve.

Connect hose from manifold to nipple at end of valve. Connect hose from "T" to nipple toward middle of valve. Position valve so end with wires faces upward, then connect wiring and install air cleaner.

Disconnect both sensor connectors. Remove sensor retaining clamp and pull sensor carefully out of holder.

Clean holder, then insert sensor fully (clamping surface about .025" from holder surface). Install retaining clamp and tighten to 70-100 INCH Lbs. (8-11 N.m). Route wires up water pump and under spark plug wires along manifold to right of throttle body.

1. Remove 10 mm retaining bolt and remove harness connector. Remove 2 bracket nuts, then remove gasket around connector.
2. From inside passenger compartment, remove 2 screws holding ECA to bracket. Slide out ECA and remove 2 screws to lift off calibration assembly.

1. Attach calibration assembly with 2 screws. Slide ECA into bracket, engaging clip in ECA flange. Position connector surface through firewall, then install 2 mounting screws.
2. Install gasket carefully and replace bracket mounting nuts. Install connector and tighten retaining bolt to 40 INCH Lbs. (4.5 N.m).

Allow exhaust manifold to cool. Disconnect wiring and remove sensor with crow's foot socket or special tool (T79P-9472-A ).

Clean mounting surface and install sensor with fingers. Use tool to tighten sensor until compression washer crushes, about 27-33 ft. lbs. (37-45 N.m), then connect wiring.

Disconnect wiring connector. Remove 3 fasteners at perimeter of sensor. Lift sensor and "O" ring seal. Cover valve to prevent foreign material from entering.

Clean top of valve and "O" ring groove. Lubricate "O" ring with silicone grease, then install in groove. Install sensor and secure with 3 self-tapping screws. Connect wiring.

Remove wiring connector from solenoids. Remove vacuum source hose at "T" and disconnect both solenoid hoses. Remove bolts from underneath fender and remove valve assembly.

Install assembly and tighten screws. Connect vacuum source hose to "T". Connect air by-pass hose to TAB solenoid (toward front f engine), then connect air diverter hose to TAD solenoid (toward firewall). Install wiring connectors.

COMPONENT RESISTANCE VALUES

EEC III COMPONENT RESISTANCE VALUES

Electronic Engine Control System Wiring Diagram. Scheme 68

Typical EEC III Vacuum Schematic. Scheme 69

See also:
• EEC-III DIAGNOSTIC CODES CHART