Engine Controls - System/component Tests - 3.8l Lincoln Continental VIII

INTRODUCTION

Prior to testing separate components or systems, it is recommended that all procedures listed in the BASIC TESTING article be performed. Since many computer controlled and monitored components will set a service code if they malfunction, check EEC-IV system and retrieve service codes. See Quick Test procedure in the appropriate TESTS W/CODES article in this section. If service codes are present see appropriate CIRCUIT TEST in the appropriate TESTS W/CODES article in this section.

Note. Testing individual components does not isolate shorts or opens. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) that has a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.

Note. For wiring diagrams not shown in testing procedures, see WIRING DIAGRAMS .

SUPERCHARGER

Note. The supercharger cannot be rebuilt or overhauled. If supercharger malfunctions, it will be necessary to replace entire supercharger assembly.

Ground Circuits

1. Using a DVOM, check for continuity to ground on ECA terminals No. 40 and 60. Resistance should be zero ohms. If not, repair open to ground.
2. Using a voltmeter, touch negative lead of voltmeter to a good ground. Touch positive lead of voltmeter to each ground terminal. With vehicle running, the voltmeter should indicate less than one volt. If voltmeter reading is greater than one volt, check for open, corrosion or loose connection on ground lead.

Power Circuits

Using a voltmeter, check for battery voltage between ECA terminal No. 1 (KAPWR) and ground. Check for battery voltage at terminals No. 37 and 57 (VPWR). If battery voltage is not present, power is not being supplied from EEC power relay. See CIRCUIT TEST B in the appropriate TESTS W/CODES article.

ENGINE SENSORS & SWITCHES (ECA INPUTS)

Note. For additional sensor testing specifications see the SENSOR RANGE CHARTS article in this section.

AIR CHARGE TEMPERATURE (ACT) SENSOR

Sensor is located in throttle body, or air cleaner, except 2.3L HSC Tempo and Topaz engine which has sensor located into intake manifold runner of No. 1 cylinder. Sensor requires a 5-volt reference signal during engine operation. With sensor disconnected, sensor may be checked by measuring resistance between sensor terminals. For specifications, see the SENSOR RANGE CHARTS article. For additional testing information and circuit testing of sensor, see CIRCUIT TEST DA in the TESTS W/CODES article.

BAROMETRIC PRESSURE SENSOR (BP)

Faults in barometric pressure sensor or circuit should set a service code. See Quick Test procedure in TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DF in the appropriate TESTS W/CODES article for sensor specifications.

CYLINDER IDENTIFICATION SENSOR (CID) & CRANKSHAFT SENSORS

CID sensor is mounted at camshaft on all engines except 2.3L OHC Mustang. The 2.3L OHC Mustang uses a crankshaft mounted sensor. Disconnect sensor connector and measure resistance across sensor terminals. Resistance should be 300-750 ohms. For additional information and circuit testing information on this sensor, see CIRCUIT TEST DR in the appropriate TESTS W/CODES article.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

Sensor is located in intake manifold cooling passage at front of most engines. Sensor is located at rear of engine on 3.0L passenger car engine and in water outlet connector at rear of cylinder head on 2.3L engine. Sensor requires a 5-volt reference signal during engine operation. With sensor disconnected, sensor may be checked by measuring resistance between sensor terminals. For specifications, see SENSOR RANGE CHARTS article. For additional testing information and circuit testing of sensor, see CIRCUIT TEST DA in the appropriate TESTS W/CODES article.

EGR VALVE POSITION (EVP) SENSOR/EGR VACUUM REGULATOR (EVR) SOLENOID

Faults in sensor or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DN also in the appropriate TESTS W/CODES article for sensor specifications and circuit testing procedure.

EGR PRESSURE FEEDBACK (PFE) SENSOR/DELTA PFE/EGR VACUUM REGULATOR (EVR) SOLENOID

These sensors are used to monitor EGR system operation. Sensors are located in the EGR system or are connected to EGR system by a vacuum/pressure tube. Faults in sensor or circuit should set a service code. See Quick Test procedure in TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DL in the appropriate TESTS W/CODES article for sensor specifications and circuit testing procedure.

HEATED GAS OXYGEN (HEGO) SENSOR

Vehicle may be equipped with one or two HEGO sensors. They are located in the exhaust pipe upstream of the catalytic converters. Faults in sensor or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST H in the appropriate TESTS W/CODES article for additional sensor specifications and circuit testing procedures. Ensure that none of the following conditions exist

1. Moisture inside sensor/harness connector.
2. HEGO sensor coated with contaminants.
3. Sensor circuit open or shorted to ground.

INERTIA SWITCH

Ensure key is off. Locate inertia switch in rear of vehicle. Push down on reset button to ensure switch is closed. Measure resistance between terminals on 2-wire switches. If resistance is 5 ohms or less, switch is okay. For additional circuit testing information refer to CIRCUIT TEST J in the appropriate TESTS W/CODES article. If resistance is greater than 5 ohms, replace switch.

Note. In closed position, reset button can be depressed an additional 1/16" against spring. This is normal and does not affect switch operation.

KNOCK SENSOR (KS)

The KS is located on cylinder block. Faults in sensor or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DG in the appropriate TESTS W/CODES article for additional sensor specifications and circuit testing procedures. Sensor is tested by substitution or by manually generating a knock to ensure sensor will set a service code.

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR

Sensor is located on engine or firewall and is connected to intake manifold by a vacuum supply hose. Remove vacuum supply hose to sensor. Install vacuum pump to sensor and apply 18 in. Hg vacuum. Sensor should hold vacuum. If sensor does not hold vacuum, replace sensor. Faults in MAP sensor or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DF in the appropriate TESTS W/CODES article for additional sensor testing and specifications.

MASS AIRFLOW (MA) SENSOR

Faults in MA sensor or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DC in the appropriate TESTS W/CODES article for sensor and circuit testing and specifications.

NEUTRAL DRIVE SWITCH (NDS) A/C INPUT

With ignition switch in off position, set DVOM to 200-ohm scale. Locate NDS switch (on transmission) and clutch switch (on clutch pedal linkage). Disconnect harness at both switches. Measure resistance across NDS terminals with transmission in NEUTRAL and across clutch switch terminals with clutch pedal fully depressed. If each resistance is greater than 5 ohms, switches are open. Replace switches. Faults in switches or switch circuits should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST TA in the appropriate TESTS W/CODES article for additional switch testing and specifications.

POWER STEERING PRESSURE SWITCH (PSPS)

1. Disconnect PSPS connector at steering gearbox. Set DVOM to 200-ohm scale and connect test leads to switch. Turn ignition switch to ON position. With steering wheel centered, resistance should be 10 ohms or less. Start engine and turn steering wheel one-half turn and then return it to centered position.
2. Resistance should change from less than 10 ohms to infinity and return to less than 10 ohms when steering wheel is returned to centered position. Faulty PSPS or circuit should set a service code. See Quick Test procedure in the TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST FF in the appropriate TESTS W/CODES article for additional switch testing and specifications.

THROTTLE POSITION SENSOR (TP OR TPS)

Faults in TP sensor or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DH in the appropriate TESTS W/CODES article for additional sensor testing and specifications. Ensure none of the following conditions exist

1. Binding throttle linkage.
2. TP sensor loose or not seated properly.
3. Throttle plate not fully closed.

VEHICLE SPEED SENSOR (VSS)

Disconnect VSS electrical connector. Using DVOM measure resistance across sensor terminals. Resistance should be 190-250 ohms. Replace sensor if not within specification. Faults in VSS sensor or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DP in the appropriate TESTS W/CODES article for additional sensor testing and specifications.

FUEL PUMP RELAY

Remove relay from vehicle. Connect battery voltage to terminal "C". Ground terminal "D". (Scheme 87) Measure resistance between terminals "A" and "B". Resistance should be less than one ohm with power applied and greater than 10 k/ohms with power removed.

Scheme 87

AIR MANAGEMENT SOLENOIDS (AM1 & AM2)

Only one solenoid is used on 2.3L HSC Tempo and Topaz and 5.0L Cougar and Thunderbird vehicles. Disconnect solenoid harness connectors and measure resistance across terminals. Resistance should be 50-100 ohms. If resistance is not as specified, replace solenoid. Faults in AM1 or AM2 solenoids or circuits should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST KC in the appropriate TESTS W/CODES article for additional solenoid and circuit testing.

CANISTER PURGE SOLENOID (CANP)

1. Disconnect CANP solenoid harness connector. Set DVOM to 200-ohm scale. Measure resistance across CANP solenoid terminals. Resistance should be 40-90 ohms. If resistance is not as specified, replace CANP solenoid.
2. Disconnect vacuum hose at CANP solenoid on manifold vacuum side. Apply 16 in. Hg vacuum to manifold vacuum side of solenoid. CANP solenoid should hold vacuum for 20 seconds.
3. Faults in CANP solenoid or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST KD in the appropriate TESTS W/CODES article for additional solenoid and circuit testing.

EXHAUST GAS RECIRCULATION (EGR) SOLENOID

See EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS & SUB-SYSTEMS .

IDLE SPEED CONTROL (ISC) SOLENOID

1. Solenoid is by-pass air type solenoid. Ensure ignition is off. Disconnect ISC solenoid harness connector. Set DVOM to 200-ohm scale. Measure resistance between ISC solenoid terminals. (Scheme 88) There is a diode in solenoid, connect DVOM (+) test lead to VPWR terminal and DVOM (-) lead to ISC terminal.
2. Resistance should be 7-13 ohms. If resistance is not within specification, replace solenoid. Faults in ISC solenoid or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article in this section. If no service code has been set, see CIRCUIT TEST KE in the appropriate TESTS W/CODES article for additional solenoid testing and specifications.

Scheme 88

SOLENOID VACUUM VALVE ASSEMBLY

Valve is used on 2.3L Tempo and Topaz California models as part of the Pulse Air system. Ports should flow air when solenoid is energized. Resistance at solenoid terminals should be 51-108 ohms. If resistance is not within specification, replace solenoid. Valve is normally closed with outlet port vented to atmosphere and inlet port closed. When energized, outlet port is connected to inlet port and vent is shut off. Solenoid operation may be checked using a 12-volt jumper to battery. Ensure solenoid is disconnected and one terminal is connected to ground. Apply vacuum to inlet port. A small amount of leakage is normal when solenoid is energized or de-energized.

FUEL SYSTEM TESTING

Note. In testing procedures, references to KOEO refer to Key On Engine Off. References to KOER are Key On Engine Running.

FUEL SYSTEM PRESSURE RELEASE

1. Remove fuel tank cap. Using Fuel Pressure Gauge (T80L-9974-B), release pressure from system at pressure relief valve (Schrader valve), located on fuel injection manifold rail.
2. If fuel pressure gauge is not available, disconnect electrical connector to inertia switch located on left side of luggage compartment. Remove fuel cap to release fuel tank pressure. Crank engine for 15 seconds to reduce system pressure.

FUEL DELIVERY

Note. For fuel system pressure testing and fuel pressure specifications, see the BASIC TESTING article.

Remove relay from vehicle. Connect battery voltage to terminal "C". Ground terminal "D". (Scheme 87) Measure resistance between terminals "A" and "B". Resistance should be less than one ohm with power applied and greater than 10 k/ohms with power removed.

FUEL PUMP TESTING

Note. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article.

Scheme 89

1. Visually inspect entire fuel delivery system for leaks, damaged or kinked lines and hoses. Ensure battery is fully charged and fuses are okay. Ensure adequate fuel is available in fuel tank. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE. Install fuel pressure gauge. With Key On Engine Off (KOEO) to activate pump, check and record fuel pressure. For fuel pressure specifications, see «FUEL PRESSURE SPECIFICATIONS»(/lincoln/continental/viii-1988-1994/remont/specifications/#fuel-pressure-specifications) article. Proceed to the appropriate step, as indicated: If fuel pressure is within specification, go to step 2). If fuel pressure is zero, go to step 5). If fuel pressure is low, go to step 11). If fuel pressure is high, go to step 12).
2. Check fuel injectors. See FUEL INJECTORS. Crank or run vehicle. Using a mechanic's stethoscope, listen for regularly spaced operating sounds at each injector. If sound is present, check fuel injectors for flow and leakage. Clean or replace injectors as necessary.
3. If injector operating sound is not present, check fuel injector resistance. See FUEL INJECTORS. If injectors are not within specification, replace as necessary. If injectors are within specification, check injector electrical connections for continuity to ECA. If no continuity exists in circuit, check for 12 volts at each injector lead.
4. If voltage is not present at injectors, see Quick Test procedure in the appropriate TESTS W/CODES article. Faults in injector circuit should set a service code. If no service code has been set, see CIRCUIT TEST H, in the appropriate TESTS W/CODES article.
5. If fuel pressure is zero, ensure battery is fully charged and key is off. Ground fuel pump lead at SELF-TEST connector. Using a jumper lead, ground FP terminal. (Scheme 89) Ensure connection is okay at pump/sender unit. Turn key on, leaving engine off. Listen for sound of fuel pump. If pump is running, go to next step. If it is not running, go to step 7).
6. Check condition of high-pressure fuel filter. If filter is free of contamination check fuel pressure regulator, go to step 12). If filter is contaminated, replace filter and recheck system pressure as in step 1) procedure.
7. Turn key off and disconnect fuel pump/sender connector. Set DVOM on 200-ohm scale. Measure resistance between pump ground at connector and chassis ground. If resistance is greater than one ohm, repair open circuit to ground. If resistance is not greater than one ohm, go to next step.
8. Ensure key is off and battery is fully charged. Disconnect harness connector from pump/sender unit. Ground FP terminal at SELF-TEST connector. With KOEO and DVOM on 20-volt scale, measure voltage at Pump Power terminal of pump/sender connector. If voltage is greater than 10.5 volts, replace pump/sender assembly. If voltage is not as specified, go to next step.
9. With KOEO, check voltage at fuel pump inertia switch. If voltage is greater than 10.5 volts at both inertia switch terminals, repair wire between inertia switch and pump. If voltage is not as specified, reset or replace inertia switch as necessary and go to next step.
10. Ensure key is off and battery is fully charged. Ground FP terminal at SELF-TEST connector. With KOEO and DVOM on 20-volt scale, measure voltage at fuel pump relay (Brown wire). If voltage is greater than 10.5 volts at relay, repair Brown wire between fuel pump relay and inertia switch. If voltage is not as specified, check voltage supply to fuel pump relay and to terminal No. 1 at ECA. For additional circuit testing information see CIRCUIT TEST J in the TESTS W/CODES article.
11. Ground FP terminal at SELF-TEST connector. Using a DVOM, check voltage at fuel pump terminal (Pink/Black wire). If voltage at fuel pump is within.5 volt of battery voltage, go to step 6). If voltage is not as specified, go to step 5).
12. Check engine compartment for leaks and ensure engine produces normal engine vacuum. See FUEL PRESSURE REGULATOR test procedure.

Scheme 90

1. Ensure key is off. Connect fuel pressure gauge to Schrader valve on fuel rail. Ensure manifold vacuum supply tube is connected to fuel pressure regulator. Start and run engine for 10 seconds. Stop engine and wait 10 seconds. Start and operate engine for 10 seconds. Stop engine and remove pressure regulator vacuum hose. (Scheme 90) Check vacuum port for fuel.
2. If fuel is present, replace fuel pressure regulator and repeat test. If fuel is not present, start and run engine for 30 seconds. Stop engine and check fuel pressure gauge. If fuel pressure does not drop, go to step 4). If fuel pressure drops more than 5 psi (.4 kg/cm 2 ) in 60 seconds, disconnect and plug fuel return line at engine. Cycle ignition key on and off until normal fuel pressure is obtained.
3. Turn key off and check fuel pressure gauge. If gauge drops more than 5 psi (.4 kg/cm 2 ) in 30 seconds, replace high pressure fuel pump (dual pump system) or fuel sender/pump assembly (single pump type). If gauge does not drop more than 5 psi (.4 kg/cm 2 ) in 30 seconds, replace fuel pressure regulator.
4. Ensure key is off. Relieve fuel pressure. Remove fuel pressure regulator. Check "O" ring, gasket and mounting surfaces for cracks, cuts or other damage. Connect vacuum pump to fuel return tube and apply 20 in. Hg. If maximum vacuum loss exceeds 10 in. Hg in 10 seconds, replace regulator. If maximum vacuum loss does not exceed 10 in. Hg in 10 seconds, recheck entire fuel delivery system for cause of fuel pressure loss.

FUEL INJECTORS

1. Connect tachometer to engine. Run engine at idle. Disconnect and reconnect injectors individually. If each injector causes a momentary drop in engine speed of at least 100 RPM, injectors are giving proper fuel delivery. RPM drop should only be momentary as ISC will attempt to re-establish correct idle RPM.
2. Replace any injectors that do not cause sufficient drop in engine speed. When test is complete and all injectors cause equal drop in speed, shut off engine. In order to check curb idle, refer to emission control specifications on decal in engine compartment.

INJECTOR CIRCUIT

1. Disconnect all injector harness connectors. Using digital ohmmeter, check resistance across terminals of each injector. See appropriate injector resistance table.
2. On models without Sequential Electronic Fuel Injection (SEFI), disconnect injector bank harness connector, check resistance of injector bank. See «INJECTOR BANK RESISTANCE»(/lincoln/continental/viii-1988-1994/remont/testing-diagnostics/#engine-controls-systemcomponent-tests-38l) . Injectors on SEFI models have each individual injector wired to the ECA. Repair wiring or replace any injector circuit not within specification.

INDIVIDUAL INJECTOR RESISTANCE (1)

INJECTOR BANK RESISTANCE

IDLE CONTROL SYSTEM

Note. See Idle Air Control Valve (IAC) and Idle Speed Control Solenoid (ISC) test procedures under SOLENOIDS. Curb idle and fast idle speed is controlled by the ECA, and is not adjustable. Some throttle bodies have a sludge-tolerant design with a special coated throttle bore. A Yellow/Black warning decal on these units warns against backing off throttle plate adjustment screw to avoid throttle plate sticking in bore. Faults in idle control system components or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article.

IGNITION SYSTEMS

Note. For additional information and descriptions see IGNITION SYSTEMS in the THEORY & OPERATION article. Perform the Spark Output Check as outlined in the BASIC TESTING article before entering these tests. Some ignition systems require that Quick Test procedure be performed prior to testing. This will retrieve trouble codes from the EEC-IV system. See the TESTS W/CODES article in this section.

IGNITION SYSTEM ACRONYMS (1)

IGNITION SYSTEM IDENTIFICATION

TFI-IV SYSTEM

Note. Before testing components and circuits of this system, ensure system is identified as to location of TFI module distributor mounted or CBD type) and if dwell is controlled by TFI module or ECA (Non-CCD or CCD type). Additional system and circuit testing for this system is located in the appropriate CIRCUIT TESTS in the appropriate TESTS W/CODES article.

PRELIMINARY CHECK

Ensure the following preliminary checks have been performed

1. Visually inspect engine compartment to ensure all vacuum hoses and spark plug wires are properly routed and securely connected.
2. Examine all wiring harnesses and connectors for damage.
3. Ensure TFI module is securely fastened to distributor base or cowl.
4. Ensure battery is fully charged.
5. All accessories should be off during diagnosis.

TEST EQUIPMENT

The following test equipment should be used in TFI-IV ignition system tests

1. Spark Tester (D81P-6666-A)
2. Volt-Ohmmeter
3. 12-Volt Test Light
4. Small Straight Pin
5. Remote Starter Switch
6. E-Core Ignition Coil (E73F-12029-AB)
7. Ignition Coil Secondary Wire

DIAGNOSTIC AIDS

Major differences between Computer Controlled Dwell (CCD) and non-CCD systems is the CCD system does not receive a START signal from the ignition switch, at TFI module (terminal No. 4), during engine cranking. CCD systems send an additional coil negative (-)/tach circuit signal to ECA from ignition module (terminal No. 4) labeled Filtered Tach Output (FTO). The following information should be noted during testing

1. A spark plug with a broken side electrode is NOT sufficient to check for spark and may lead to incorrect results.
2. When instructed to inspect a wiring harness, both a visual inspection and a continuity test should be performed.
3. When making measurements on a wiring harness or connector, perform a WIGGLE test while measuring.
4. References to SPOUT in-line connector apply to both in-line and shorting-bar type connectors.
5. Test procedures are intended to identify faulty components or wiring while fault is present. If complaint is an intermittent condition, see the TESTS W/O CODES article in this section.

PRIMARY CIRCUIT TEST (EXCEPT CLOSED BOWL DISTRIBUTOR)

1. Disconnect terminal "S" at starter relay to allow testing of ignition primary circuit without cranking motor. Ensure ignition is off. Push down on connector tab and disconnect harness connector from TFI module. Ensure TFI module connector is not corroded or swollen. Repair or replace connector as necessary. NOTE: If connector is damaged or has broken tabs due to misuse, replace connector. A loose or damaged connector may cause ignition signal faults during KOER operation.
2. Use a straight pin or terminal spade from an old TFI module to probe connector. Attach negative DVOM lead to distributor base. Avoid ground contact with straight pin or positive terminal lead during testing. Determine if vehicle system has Computer Controlled Dwell (CCD). See «IGNITION SYSTEM IDENTIFICATION»(/lincoln/continental/viii-1988-1994/remont/testing-diagnostics/#engine-controls-systemcomponent-tests-38l). Turn ignition on and measure voltage at following TFI module harness connector terminals: (Scheme 91)

Key On Engine Cranking (KOEC)

1. No. 3 (Power/Run Circuit)
2. No. 4 (Start Circuit)

Key On Engine Off (KOEO)

1. No. 3 (Power/Run Circuit)

1. No. 3 (Power/Run Circuit)

Scheme 91

1. No. 3 (Power/Run Circuit)

3) Turn ignition off and remove test pin. Reconnect wire to "S" terminal on relay. If approximately 90% of Battery Voltage (VBAT) is not present at these terminals, repair open circuits in wiring harness as necessary. Check ignition switch for faults. See appropriate wiring diagram. If voltage was as specified, reconnect module and go to next step.

4) Attach a 12-volt test light between ground and coil negative (-)/tach terminal No. 2 at TFI module. Turn ignition on and crank engine. If test light flashes brightly during cranking, go to PIP Sensor/Stator Test. If test light stays on during cranking, check for open in coil negative circuit between coil and TFI module connector. Repair circuit as necessary. If no open circuits are found, ignition module is shorted internally, replace TFI module and retest.

5) If test light is always dim or off during cranking, check voltage to coil positive (+) terminal. If voltage is not present with key on or during cranking, repair open in primary circuit between battery and coil positive (+). If light flashes intermittently, check ignition module resistance. If voltage is available at coil, go to COIL TEST and check ignition coil.

Scheme 92

1. Disconnect terminal "S" at starter relay to allow testing of ignition primary circuit without cranking motor. Ensure ignition is off. Push down on connector tab and disconnect harness connector from TFI module. Ensure TFI module connector is not corroded or swollen. Repair or replace connector as necessary. NOTE: If connector is damaged or has broken tabs due to misuse, replace connector. A loose or damaged connector may cause ignition signal faults during KOER operation.
2. Use a straight pin or terminal spade from an old TFI module to probe connector. Avoid ground contact, between straight pin and ground, during testing. Using a DVOM, turn ignition on and measure voltage at following vehicle harness connector terminals of the cowl mounted TFI module: (Scheme 92) Key On Engine Cranking (KOEC) No. 2 (Coil Negative) No. 3 (Power/Run Circuit) No. 4 (Start Circuit - Non-CCD Systems) Key On Engine Off (KOEO) No. 2 (Coil Negative) No. 3 (Power/Run Circuit) If approximate Battery Voltage (VBAT) is not present at these terminals, repair open circuits in wiring harness as necessary. See appropriate wiring diagram in WIRING DIAGRAMS at the end of this article.
3. If battery voltage is as specified, check module ground circuit. With TFI module disconnected and KOEO, measure voltage at terminal No. 6. If voltage is greater than.5 volt, ground circuit has high resistance or is open. Repair as necessary.
4. Ensure ignition is off, disconnect distributor connector. Turn ignition on. With DVOM set on DC voltage scale, connect positive (+) lead to terminal No. 8. Connect negative (-) lead to distributor or engine ground. (Scheme 92)
5. Cycle ignition switch between ON and START positions. Battery voltage should be present in both positions. If not, service or repair circuit as necessary. If okay, go to next step.
6. Use a DVOM to check ignition ground circuits continuity. Measure resistance between distributor base and terminals No. 2 and No. 6 at distributor connector. If resistance at each terminal is less than 3 ohms, circuit is okay. If resistance is not less than 3 ohms, repair ground circuit as necessary.

TFI MODULE RESISTANCE TEST

1. Remove TFI module from distributor or disconnect cowl. Measure resistance of TFI module circuits. See «TFI MODULE RESISTANCE»(/lincoln/continental/viii-1988-1994/remont/testing-diagnostics/#engine-controls-systemcomponent-tests-38l). (Scheme 92)
2. If resistance is as specified, suspect faulty PIP sensor/stator. If resistance is NOT as specified, replace TFI-IV module.

TFI MODULE RESISTANCE

PIP SENSOR/STATOR TEST (EXCEPT CLOSED BOWL DISTRIBUTOR)

1. Ensure TFI module mounting screws are tight on distributor. Turn ignition off. Remove coil wire at distributor cap and ground end of wire. Ensure wire does not break contact with ground during this test.
2. Disconnect SPOUT connector located near distributor. Connect positive (+) lead of DVOM to TFI module side of SPOUT connector and negative lead to distributor base.
3. Turn ignition switch to ON position and bump starter to rotate engine a small amount. Measure and record voltage (allow DVOM voltage reading to stabilize). Repeat procedure 10 times. Voltage should vary as hall sensor vanes and windows rotate through PIP sensor.
4. Voltage reading should vary between .5 volt and 11.5 volts (90% of battery voltage). If the higher voltage readings are only about 70% of battery voltage, go to TFI MODULE RESISTANCE TEST. If TFI module has excessive resistance,replace TFI module. If resistance is not excessive, replace PIP sensor.
5. If the lower voltage readings are greater than .5 volt and ignition module resistance is within specification, replace PIP sensor. If PIP sensor and module test okay, go to next step to check for PIP signal at ECA during cranking.
6. Turn ignition off and install Break Out Box (BOB) at ECA connector. Connect a DVOM between test terminals No. 56 (PIP) and No. 16 (IGN GND). Measure PIP signal voltage while cranking engine. Voltage should vary between 4 and 6 volts. If not, check for an open or grounded PIP circuit or an open IGN GND circuit at test terminal No. 16. Repair circuits as necessary. If circuits are okay, but PIP signal is erratic or not present, go to next step.
7. With ECA and TFI module disconnected, connect DVOM positive (+) lead to PIP circuit at harness connector and ensure circuit is not shorted to power during engine cranking. If circuit is okay, replace TFI module and retest system.

PIP SENSOR/STATOR TEST (CLOSED BOWL DISTRIBUTOR)

1. With ignition off, ensure distributor is connected to vehicle harness. Disconnect vehicle harness connector at TFI module. Connect DVOM positive (+) lead to terminal No. 6 at TFI vehicle harness connector. Connect negative (-) lead to ground.
2. Crank engine and measure DC voltage. Voltage should vary between 4 and 6 volts. If voltage varies, test SPOUT circuit. If voltage does not vary go to next step.
3. With ignition off, disconnect distributor connector. Using DVOM, measure resistance between terminals No. 1 and No. 5 at distributor connector. If resistance is greater than 200 ohms, replace faulty PIP sensor.
4. Disconnect vehicle harness connector at TFI module. Measure resistance between terminal No. 6 (PIP) at TFI module vehicle harness connector and terminal No. 5 (PIP to TFI Module) at distributor vehicle harness connector. If resistance is greater than 5 ohms, repair open in circuit and retest. Check circuit for short to ground. Test circuit for short to power with KOEO. Service or replace wiring as necessary.
5. Disconnect ECA connector and measure resistance between terminal No. 56 (PIP) at ECA 60-pin connector and terminal No. 5 (PIP to ECA Module) at distributor vehicle harness connector. If resistance is greater than 5 ohms, repair open in circuit and retest. Check circuit for short to ground. Test circuit for short to power with KOEO. Service or replace wiring as necessary.
6. Measure resistance between distributor connector terminal No. 2 (PIP SIG GND) and ground. Measure resistance between IGN GND, distributor connector terminal No. 6 (terminal No. 3 on 3.0L Aerostar or Ranger) and ground. If resistance is less than one ohm in both cases, ground circuit is okay. If resistance is not less than one ohm in both cases, check PIP sensor mounting screws in distributor base for corrosion and tightness.

COIL TEST

1. Attach negative (-) VOM lead to distributor base and measure battery voltage. Turn ignition switch to RUN position. Measure voltage at coil positive (+) terminal of ignition coil and turn ignition off. Voltage should be 10.5-12 volts. If voltage is as specified, go to next step. If voltage is not as specified, repair ignition switch or wiring circuit to coil. See appropriate wiring diagram in WIRING DIAGRAMS at the end of this article.
2. Ensure ignition is off. Disconnect coil primary connector and inspect both contacts for corrosion or damage. Service or replace as necessary. Using a DVOM, measure primary circuit resistance. If resistance is not 0.3-1.0 ohm at 70°F, replace coil and retest system.
3. Remove secondary coil wire from coil tower and inspect contact for signs of arcing or corrosion. Using a DVOM, measure resistance between coil tower connector and coil negative (-) terminal. If resistance is not 8000-11,500 ohms, replace coil.

Scheme 93

1. This procedure is applicable to all TFI-IV equipped vehicles. Spark advance is controlled by ECA. This procedure checks the capability of ignition module to receive spark timing commands from ECA on the SPOUT circuit. A varying voltage signal is necessary on SPOUT circuit for ECA to transmit data. A KOER Code 18 or Code 213 may be set when SPOUT circuit is open or shorted. For additional information on TFI ignition systems see THEORY/OPERATION article.
2. Check SPOUT circuit coltage at TFI module. Ensure key is in OFF position. Disconnect SPOUT in-line connector near TFI module. (Scheme 93) If connector is SHORTING BAR type, remove SHORTING BAR.
3. Attach negative (-) voltmeter lead to distributor base and positive (+) lead to TFI module side of the SPOUT connector. Start engine and measure voltage at idle. Measure voltage at ECA side of SPOUT connector.
4. Voltage readings should be 4-8 volts. If voltage on TFI module side is okay, TFI module is okay. This voltage signal is necessary for TFI module to receive ECA SPOUT signal. If voltage signal from ECA to SPOUT connector is as specified, circuit from ECA to SPOUT connector is okay. If either voltage signal is not as specified, go to next test. If both voltage signals are as specified, check ignition timing advance.
5. Check SPOUT circuit continuity. Push TFI module connector tab to release connector. Separate wiring harness connector from ignition module. Inspect for dirt, corrosion and damage.
6. Using a small straight pin inserted into harness connector terminal No. 5, measure resistance between terminal and TFI module side of SPOUT connector. Resistance should be less than 5 ohms. If resistance is not less than 5 ohms, repair wiring as necessary.
7. Measure resistance between ECA side of SPOUT connector and pin No. 36 at ECA connector. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair wiring between SPOUT connector and ECA.
8. Check Ignition Timing Advance. With SPOUT connector disconnected, run engine at idle and ensure timing is at base timing adjustment. See the ADJUSTMENTS article. Stop engine.
9. Connect SPOUT connector and start engine. Timing should advance from base timing specification. Increase engine RPM and ensure timing advances. If time does not advance, check TFI module. If module is okay, replace ECA.

Scheme 94

Scheme 95

Scheme 96

Scheme 97

Air Supply Pump

Check belt tension and adjust to proper tension, if necessary. Disconnect air supply hose from by-pass control valve. Start engine. Pump is operating satisfactorily if airflow is felt at pump outlet and airflow increases as engine speed is increased. If this condition is not met, replace pump.

Air Silencer/Filter (Air Pump & Pulse Air Inlet)

Inspect hoses and air silencer for leaks. Disconnect hose from air silencer outlet. Remove silencer from vehicle and visually inspect for plugging. If no plugging or leaks are found, silencer is okay. If any plugging or leaks are found, repair or replace as required.

Scheme 98

1. Disconnect air supply hose at valve outlet. (Scheme 98) Remove vacuum line from vacuum nipple and check for presence of vacuum at nipple. There must be vacuum present at nipple before proceeding.
2. Reconnect vacuum line to vacuum nipple. With engine at 1500 RPM, air pump supply air should be heard and felt at air by-pass valve outlet.
3. With engine still at 1500 RPM, disconnect vacuum line. Air at outlet should decrease significantly or shut off. Air pump supply air should now be heard or felt at the silencer ports, or at the dump port.
4. If the normally closed air by-pass valve does not perform as described in steps 2) and 3), check the air pump for faults. If air pump is operating satisfactorily, replace air by-pass valve.

Air Check Valve

1. Visually inspect thermactor hoses, tubes, control valve(s) and check valve(s) for leaks that may be due to backflow of exhaust gases. If holes are found and/or traces of exhaust gas products are evident, check valve may be suspect.
2. Valve should allow free flow of air in direction of arrow only. (Scheme 99) The valve(s) should check (or block) the free flow of exhaust gas air in the opposite direction.
3. If air does not flow as indicated or if exhaust gas backflows opposite of direction of arrow in illustration, replace check valve.

Scheme 99

Scheme 100

1. Disconnect air supply hose at inlet. Accelerate engine to 1500 RPM and verify presence of airflow in hose. Reconnect air supply hose to valve inlet.
2. Disconnect air supply hoses at outlets "A" and "B". (Scheme 100) Remove vacuum line at vacuum nipple. Accelerate engine to 1500 RPM. Airflow should be heard and felt at outlet "B" with little or no airflow at outlet "A".
3. Connect a vacuum line from manifold vacuum fitting to air supply control valve vacuum nipple. Accelerate engine to 1500 RPM. Airflow should be heard and felt at outlet "A" with little or no airflow at outlet "B".
4. If valve does not meet above conditions, replace valve. If airflow operates as described in steps 1), 2) and 3), valve is okay. Reinstall hoses and clamps.

Scheme 101

1. Disconnect air supply hose at inlet. Accelerate engine to 1500 RPM and verify presence of airflow in hose. Reconnect air supply hose to valve inlet.
2. Carefully disconnect the air supply hoses at outlets "A" and "B". (Scheme 101) Carefully remove vacuum line at vacuum nipple. Accelerate engine to 1500 RPM. Airflow should be heard and felt at outlet "B" with little or no airflow at outlet "A".
3. Connect a vacuum line from manifold vacuum fitting to air control valve vacuum nipple. Accelerate engine to 1500 RPM. Airflow should be heard and felt at outlet "A" with little or no airflow at outlet "B".
4. If the conditions in steps 2) and 3) are not met, replace the air control valve. If the valve operates satisfactorily, restore all hose and vacuum connections.

Air Pump Resonator

Visually inspect for holes. Remove hoses and check for restricted ports. Replace resonator if holes or ports are restricted. Reconnect hoses and install clamps.

Scheme 102

1. Disconnect hoses from outlets "A" and "B". (Scheme 102) Disconnect and plug vacuum line to port "D". With engine operating at 1500 RPM, airflow should be noted coming out of by-pass vents.
2. Reconnect vacuum line to port "D". Disconnect and plug vacuum line to port "S". Ensure vacuum is present in line to vacuum port "D". Accelerate engine to 1500 RPM. Airflow should be noted coming out of outlet "B". No airflow should be detected at outlet "A".
3. Apply 8-10 in. Hg vacuum to port "S". With engine operating at 1500 RPM, airflow should be noted coming out of outlet "A". If valve is bleed type, less air will flow from outlet "A" or "B", and the main discharge will change when vacuum is applied to port "S".
4. If the conditions in the above steps are not met, replace valve. If above conditions are met, valve is okay. Reconnect hoses and vacuum lines.

Dual Thermactor Air Control Solenoid Valve

The function of each valve can be determined by externally energizing the valve with vacuum lines attached. Check the resistance of each solenoid. Resistance should be 51-108 ohms when checked at the coil terminals. If the resistance is not 51-108 ohms, solenoid should be replaced.

Thermactor Idle Vacuum (TIV) Valve

1. With engine at idle and transmission in NEUTRAL, apply vacuum to small nipple and place fingers over the TIV valve atmospheric vent holes. (Scheme 103) If no vacuum is sensed, the TIV is damaged and must be replaced. If vacuum is sensed, go to next step.
2. With engine still at idle, apply vacuum to TIV valve large nipple from using a vacuum pump. See «TIV VALVE (LARGE NIPPLE) VACUUM SPECIFICATIONS»(/lincoln/continental/viii-1988-1994/remont/testing-diagnostics/#engine-controls-systemcomponent-tests-38l). If vacuum is not held, the TIV is damaged and must be replaced. If no vacuum is sensed, replace valve.

Scheme 103

TIV VALVE (LARGE NIPPLE) VACUUM SPECS

Scheme 104

1. A 2-port valve may be in open or closed position when engine is cold, but should reverse when engine is warmed to operating temperature.
2. For 3-port valves, with a cold engine, passage "A" to "B" should be closed and passage "A" to "C" should be open. (Scheme 104) With engine at normal operating temperature, the VCV should be open between "A" and "B" and closed between "A" and "C".
3. For the 4-port valve, check "A1" to "B1" and "A2" to "B2" separately. (Scheme 104) A 4-port valve may be in open or closed position when engine is cold, but should reverse when engine is warmed to operating temperature. If these conditions are not met, replace the valve.

Scheme 105

1. Electrical vacuum control valve may be either open or closed at room temperature, but should reverse the position when engine is at full operating temperature. While engine is cold, measure continuity across switch terminals. (Scheme 105) Note if switch is open or closed.
2. Warm engine to normal operating temperature. Measure continuity across switch terminals again. Continuity should be opposite of cold condition. If switch continuity does not switch, replace valve. Check vacuum function of valve as described in VACUUM CONTROL VALVE above.

Vacuum Check Valve

Apply 16 in. Hg vacuum to check side of valve and trap. If vacuum remains greater than 15 in. Hg for 10 seconds, valve operation is normal. If vacuum drops faster, replace valve.

Vacuum Reservoir

When charged with 15-20 in. Hg vacuum, vacuum loss should not exceed 0.5 in. Hg in 60 seconds. If vacuum loss is faster, replace reservoir.

Pulse Air Valve

With engine at normal operating temperature and at curb idle, remove inlet hose from valve. A suction should be felt at valve inlet. If suction is not felt, replace valve.

Electronic EGR Valve (EEGR) & Pressure Feedback Electronic (PFE)

1. Ensure all vacuum hoses are correctly routed and securely attached. Replace any crimped or broken hoses. Ensure there is less than 1 in. Hg vacuum to EGR valve at idle with engine at normal operating temperature. NOTE: EVR solenoid has a constant internal leak. You will notice a small vacuum signal of less than 1 in. Hg vacuum at idle.
2. Install tachometer. Disconnect Idle Air By-Pass Valve electrical connector (if equipped). Remove and plug vacuum hose at EGR valve. Start engine and idle in neutral. Note idle speed. Using hand vacuum pump, slowly apply 5-10 in. Hg vacuum to EGR valve. When vacuum is fully applied to EGR valve, engine should do one or more of the following: Engine should stall Idle speed should drop more than 100 RPM Idle speed should return to normal when vacuum is released
3. Repair or replace EGR valve if none of the above occurs. Reconnect idle air by-pass valve electrical connector. Unplug and reconnect vacuum hose at EGR valve.

EGR Vacuum Regulator (EVR)

Faults in EVR or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DN in TESTS W/CODES article for diagnostic procedures.

EGR Solenoid

Remove EGR solenoid harness connector. Measure resistance across solenoid terminals. Resistance should be 65-110 ohms. Set DVOM to 200-k/ohm scale. Measure resistance between each solenoid terminal and ground or side of solenoid. Resistance should be greater than 10 k/ohms. If resistance is not as specified in either test, replace solenoid.

Differential Pressure Feedback Electronic (DPFE) Transducer

Faults in DPFE transducer or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DL in the TESTS W/CODES article for diagnostic procedures.

Pressure Feedback Electronic (PFE) Transducer

Faults in PFE transducer or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST DL in the appropriate TESTS W/CODES article for diagnostic procedures.

Apply 16 in. Hg vacuum to check side of valve and trap. If vacuum remains greater than 15 in. Hg for 10 seconds, valve operation is normal. If not, replace valve.

When charged with 15-20 in. Hg vacuum, vacuum loss should not exceed 0.5 in. Hg in 60 seconds. If it does, replace reservoir.

Canister Purge Regulator (CPR) Valve

With CPR valve de-energized, apply 5 in. Hg vacuum to source port. Valve should not pass air. Apply 9-14 volts to one electrical terminal and ground the other. Valve should open and pass air. If valve does not operate as described, replace valve.

Canister Purge (CANP) Solenoid

Faults in CANP solenoid or circuit should set a service code. See Quick Test procedure in the appropriate TESTS W/CODES article. If no service code has been set, see CIRCUIT TEST KD in the appropriate TESTS W/CODES article for diagnostic procedures.

EVAP Canister

There are no moving parts in canister. Check for loose, missing, cracked or broken connections or parts. Repair or replace as necessary. There should be no liquid in canister.

PCV Valve

1. Remove PCV valve from rocker cover grommet. On 5.0L cars, PCV valve is located on top of cylinder block near firewall. Shake valve. Valve should rattle when shaken. If valve does not rattle, replace valve.
2. Start engine and warm to normal operating temperature. On 2.3L HSC and 2.5L, remove corrugated hose from oil separator nipple. Place stiff piece of paper over nipple end and wait 60 seconds.
3. On all other models, disconnect hose from remote air cleaner or outlet tube. Place stiff piece of paper over hose end and wait 60 seconds. Vacuum should hold paper in place. If vacuum does not hold paper in place, replace valve.

Air Cleaner Temperature Sensor

Bring temperature of sensor below 75°F and apply 8 in. Hg vacuum to source port. Duct door should close. If door does not close, replace sensor. Sensor will bleed off vacuum to allow duct door to open and let in fresh air at specific temperatures. See AIR CLEANER TEMPERATURE SENSOR OPENING .

AIR CLEANER TEMPERATURE SENSOR OPENING

Air Control Door

When a vacuum of 8 in. Hg or more is applied to vacuum motor, door should stay in proper position for as long as vacuum is applied. If vacuum bleeds off and door returns to rest position, replace vacuum motor.

2.3L Tempo & Topaz EEC-IV Wiring Diagram. Scheme 106

2.5L Taurus EEC-IV Wiring Diagram. Scheme 107

3.0L Probe EEC-IV Wiring Diagram. Scheme 108

3.0L Sable & Taurus EEC-IV Wiring Diagram (Except SHO). Scheme 109

3.8L Continental EEC-IV Wiring Diagram (1 of 2). Scheme 110

3.8L Continental EEC-IV Wiring Diagram (2 of 2). Scheme 111

3.8L Cougar & Thunderbird EEC-IV Wiring Diagram (Exc. SC). Scheme 112

3.8L Sable & Taurus EEC-IV Wiring Diagram (1 of 2). Scheme 113

3.8L Sable & Taurus EEC-IV Wiring Diagram (2 of 2). Scheme 114

5.0L Cougar & Thunderbird. Scheme 115

5.0L Crown Victoria & Grand Marquis (California). Scheme 116

5.0L Crown Victoria & Grand Marquis (Federal). Scheme 117

5.0L Mark VII EEC-IV Wiring Diagram. Scheme 118

5.0L Mustang EEC-IV Wiring Diagram. Scheme 119

See also:
• FUEL PRESSURE SPECIFICATIONS
• WIRING DIAGRAMS