Engine Controls - System & Engine Component Tests - Eec-V (gasoline) Lincoln Town Car III

INTRODUCTION

Note. Information for Escort applies to Escort ZX2, unless otherwise indicated.

Before testing separate components or systems, perform appropriate procedures in BASIC DIAGNOSTIC PROCEDURES article. Since many computer-controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

Note. Testing individual components does not isolate short or open circuits. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate shorted or open wiring harness. For identification of circuits and terminals referenced in test procedures, see WIRING DIAGRAMS article.

Ground Circuits

1. Turn ignition off. Locate PCM. See POWERTRAIN CONTROL MODULE LOCATION table. Using a DVOM, check continuity between ground and PCM connector pins. See «IDENTIFYING PCM GROUND PINS»(/lincoln/town-car/iii-1997-2003/remont/testing-diagnostics/#engine-controls-system-engine-component-tests-eec-v-gasoline) table. (Scheme 1)and (Scheme 2). If continuity does not exist, repair open ground circuit as necessary. If continuity exists, go to next step. IDENTIFYING PCM GROUND PINS Application PCM Ground Pin No. Continental, Crown Victoria, Grand Marquis & Town Car 3, 25, 51, 77 & 103 Contour, Cougar & Mystique 24, 51, 77 & 103 Econoline 4.2L & 4.6L 24, 25, 51, 76, 77 & 103 5.4L 3, 24, 25, 51, 77 & 103 6.8L 3, 23, 24, 25, 51, 76, 77 & 103 Expedition & Navigator 3, 25, 51, 77 & 103 LS A24, A25, A26 & A27 Mustang 24, 25, 51, 76, 77 & 103 3.8L 24, 25, 51, 76, 77 & 103 4.6L 2-Valve 3, 25, 51, 77 & 103 4.6L 4-Valve 25, 51, 77 & 103 Pickup F150 & F250 4.2L & 4.6L 24, 25, 51, 76, 77 & 103 5.4L 3, 25, 51, 77 & 103 Super-Duty Models 3, 23, 24, 51, 76, 77 & 103 Ranger 24, 25, 51, 76, 77 & 103 Sable & Taurus 24, 25, 51, 76, 77 & 103 Windstar 3.0L 24, 51, 76, 77 & 103 3.8L 24, 25, 51, 76, 77 & 103
2. Touch negative lead of voltmeter to a good ground. With vehicle running, backprobe positive lead of voltmeter to each ground terminal. Voltmeter should indicate less than one volt. If reading is greater than one volt, check for open, corrosion or loose connection on ground lead.

Power Circuits

Turn ignition off. Using a voltmeter, check for battery voltage between ground and PCM pin No. A44 (KAPWR) on LS or pin No. 55 (KAPWR) on all other models. Turn ignition switch to START or RUN position. Check for battery voltage between ground and VPWR fuse on LS or PCM connector pin No. 71 (VPWR). If battery voltage is not present, power is not being supplied from PCM power relay. See TEST B under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

POWERTRAIN CONTROL MODULE LOCATION

Identifying Powertrain Control Module (PCM) Connector Pins (Except LS). Scheme 1

Scheme 2

ENGINE SENSORS & SWITCHES

Note. For additional sensor testing specifications, see appropriate SENSOR OPERATING RANGE CHARTS article.

Clutch Pedal Position (CPP) Switch

See TEST TA under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for testing procedures and specifications.

Inertia Fuel Shutoff (IFS) Switch

Ensure ignition is off. Locate IFS switch. See appropriate INERTIA FUEL SHUTOFF (IFS) SWITCH LOCATION TABLE (CARS) or INERTIA FUEL SHUTOFF (IFS) SWITCH LOCATION TABLE (TRUCKS & VANS) table. Shake or jar IFS switch to cause switch to open. IFS switch reset button should pop up. Fuel pump should not operate and car should stall. Push down on reset button. Restart engine. Fuel pump should operate.

INERTIA FUEL SHUTOFF (IFS) SWITCH LOCATION (CARS)

INERTIA FUEL SHUTOFF (IFS) SWITCH LOCATION (TRUCKS & VANS)

Park/Neutral Position (PNP) Switch

See TEST TA under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article, for PNP switch testing procedures.

Engine Coolant Temperature (ECT) Sensor

Sensor uses a 5-volt reference voltage during engine operation. To check ECT signal voltage, backprobe between signal terminal and ground with engine running. To check sensor resistance, disconnect sensor connector and measure resistance between sensor terminals. For ECT sensor specifications, see ECT SENSOR SPECIFICATIONS table. For additional testing information, see TEST DA under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

ECT SENSOR SPECIFICATIONS (1)

Heated Oxygen Sensor (HO2S)

Faults in sensor or circuit should set a Diagnostic Trouble Code (DTC). See QUICK TEST in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. To check HO2S heater resistance, go to step 34) of TEST H under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

Intake Air Temperature (IAT) Sensor

Note. On some models, IAT sensor is part of Mass Airflow (MAF) sensor assembly. If all 6 terminals of MAF sensor connector are being used, IAT sensor is integral to MAF sensor. See WIRING DIAGRAMS article.

Sensor uses a 5-volt reference voltage during engine operation. To check IAT signal voltage, backprobe between signal terminal and ground with engine running. To check sensor resistance, disconnect sensor and measure resistance between sensor terminals. For specifications, see IAT SENSOR SPECIFICATIONS table. For additional testing information, see TEST DA under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

IAT SENSOR SPECIFICATIONS (1)

Mass Airflow (MAF) Sensor

Faults in MAF sensor or circuit should set a Diagnostic Trouble Code (DTC). See QUICK TEST in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. If no diagnostic trouble code has been set, go to TEST DC under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for MAF sensor and circuit testing.

Output Shaft Speed (OSS) Sensor

Faults in MAF sensor or circuit should set a Diagnostic Trouble Code (DTC). See QUICK TEST in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. If no diagnostic trouble code has been set, go to TEST TJ under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for OSS sensor and circuit testing.

Throttle Position (TP) Sensor

Ensure none of following conditions exist

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

Faults in TP sensor or TP sensor circuits should set a Diagnostic Trouble Code. See QUICK TEST in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. If no DTCs are present, see TEST DH under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for additional TP sensor testing and specifications.

RELAYS

Note. To identify fuel pump relay terminals, refer to numbers molded on relay. Two different numbered relays are used. Fuel pump relay terminals may be numbered 1-5 or terminals may be numbered 30, 85, 86, 87 and 87A. On relays that are numbered 1-5, terminals for relay coil are terminals No. 1 and 2. On relays that are numbered 30, 85, 86, 87 and 87A, terminals for relay coil are terminals No. 85 and 86.

Fuel Pump Relay

1. Turn ignition off. On fuel pump relays that terminals are numbered 1-5, measure resistance between relay terminal No. 1 and all other relay terminals. Resistance should be 40-120 ohms between terminals No. 1 and 2 and more than 10,000 ohms between terminal No. 1 and other relay terminals.
2. On fuel pump relays that terminals are numbered 30, 85, 86, 87 and 87A, measure resistance between relay terminal No. 85 and all other relay terminals. Resistance should be 40-120 ohms between terminals No. 85 and 86 and more than 10,000 ohms between terminal No. 85 and other relay terminals. On both relays, if resistance is not as specified replace relay. If resistance is okay, see TEST KA under SYSTEM TEST in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for additional fuel pump circuit testing procedures.

Fuel Shutoff Valve Relay

Note. To identify Fuel Shutoff Valve (FSV) relay terminals, refer to numbers molded on relay. FSV relay is also referred to as fuel valve relay.

1. Turn ignition off. Measure resistance between terminals No. 85 and 86 at FSV relay. Resistance should be 40-120 ohms. Also measure resistance between terminal No. 85 and terminals No. 30 and 87 at FSV relay. Resistance should be more than 10,000 ohms. If resistance is not as specified, replace FSV relay.

Air Injection By-Pass Solenoid

See SECONDARY AIR INJECTION under EMISSION SYSTEMS & SUB-SYSTEMS.

Air Injection Diverter Solenoid

See SECONDARY AIR INJECTION under EMISSION SYSTEMS & SUB-SYSTEMS.

Canister Vent (CV) Solenoid

See FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS.

EGR Vacuum Regulator (VR) Solenoid

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

Fuel Rail Solenoid

See TEST DD under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for additional testing and specifications.

Idle Air Control (IAC) Solenoid Resistance

See IDLE AIR CONTROL SOLENOID under IDLE CONTROL SYSTEM.

Intake Manifold Tuning (IMT) Valve Vacuum Solenoid

See TEST HU under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for additional testing and specifications.

Supercharger (Boost) By-Pass (SCB) Solenoid

Turn ignition off. Disconnect SCB solenoid connector. Measure resistance between SCB solenoid terminals. If resistance is not 68-78 ohms, replace solenoid. If resistance is 68-78 ohms, IAC solenoid is okay. See TEST KJ under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for additional testing and specifications.

Variable Cam Timing (VCT) Solenoid

See TEST HK under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for additional testing and specifications.

With Fuel Pressure Gauge

Remove fuel tank cap to release fuel tank pressure. Connect Fuel Pressure Gauge (T80L-9974-B) to pressure relief valve (Schrader valve) located on fuel injection manifold rail. Using a suitable container, release fuel pressure.

Without Fuel Pressure Gauge

If fuel pressure gauge is not available, disconnect Inertia Fuel Shutoff (IFS) switch. For IFS location, see INERTIA FUEL SHUTOFF (IFS) SWITCH LOCATION TABLE (CARS) or INERTIA FUEL SHUTOFF (IFS) SWITCH LOCATION TABLE (TRUCKS & VANS) under ENGINE SENSORS & SWITCHES. Remove fuel cap to release fuel tank pressure. Crank engine for 15 seconds to release system pressure.

See RELAYS under RELAYS & SOLENOIDS.

System Integrity Check

Perform the following checks

1. Visually inspect fuel system (fuel lines, filter, pump, injectors, pressure regulator, etc.).
2. Ensure Inertia Fuel Shutoff (IFS) switch reset button is not in upper (tripped) position.
3. Ensure battery is fully charged and fuel-related fuses are okay.
4. Check fuel tank contents and fuel gauge accuracy. On vehicles with 2 fuel tanks, check both tanks. If any fault is detected, repair as necessary. If system checks are okay, go to «CHECK FUEL PRESSURE»(/lincoln/town-car/iii-1997-2003/remont/testing-diagnostics/#engine-controls-system-engine-component-tests-eec-v-gasoline__check-fuel-pressure) .

Check Fuel Pressure

Install fuel pressure gauge. Start engine and record fuel pressure. See FUEL PRESSURE SPECIFICATIONS . If fuel pressure is as specified, testing is complete. If fuel pressure is not as specified, go to TEST HC under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

FUEL PRESSURE REGULATOR

See TEST HC under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

Fuel Injector Resistance

Disconnect injector harness connectors. Using digital ohmmeter, measure resistance between injector terminals. If resistance of any injector is not 11-18 ohms, replace injector.

Fuel Injector Check

Start engine and allow to idle. If engine will not start, crank engine for 10 seconds. Using a stethoscope, listen for clicking sound at each injector. If clicking sound is heard, fuel injector is operating. If clicking sound is not heard, go to step 57) of TEST H under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

IDLE AIR CONTROL SOLENOID

Solenoid is by-pass air type. Ensure ignition is off. Disconnect IAC solenoid harness connector. Measure resistance between IAC solenoid connector terminals. Solenoid has diode and resistance will be infinite if voltmeter is hooked up wrong. If resistance is not 6-13 ohms, replace solenoid. If resistance is 6-13 ohms, IAC solenoid is okay. See TEST KE under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article for additional testing and specifications.

IGNITION SYSTEMS

Note. For additional information and descriptions, see IGNITION SYSTEMS in THEORY & OPERATION - ECC-V article

Faults in ignition system may set a Diagnostic Trouble Code. See QUICK TEST in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. If any DTCs are present, perform appropriate system test. If no DTCs are present, check secondary ignition system. See TEST JB under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

EXHAUST CATALYST

1. Disable secondary air injection system. Run engine at 2500 RPM for 2 minutes. Turn ignition off. Disconnect and ground one spark plug wire or disconnect one ignition coil for coil on plug applications.
2. Start engine and run at 1000 RPM. Disconnect IAC valve. Using an infrared temperature probe, measure surface temperature at catalytic converter inlet and outlet. Outlet temperature should be at least 50°F (28°C) greater than inlet temperature. Replace catalytic converter if necessary. Reconnect ignition system, IAC valve and secondary air injection.

SECONDARY AIR INJECTION

Faults in Secondary Air Injection (AIR) system should set a Diagnostic Trouble Code. See QUICK TEST in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. If any DTCs are present, perform appropriate system test. If no DTCs are present, check AIR system. See TEST HM under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

EGR Valve

1. Ensure all vacuum hoses are correctly routed and securely attached. Replace any crimped or broken hoses. Ensure there is less than one in. Hg vacuum to EGR valve at idle with engine at normal operating temperature.
2. Install tachometer. Disconnect Idle Air Control (IAC) wiring harness connector. Remove and plug vacuum hose at EGR valve. Start engine. 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, 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. Service or replace EGR valve if engine does not stall or idle speed does not respond as specified. Reconnect IAC harness connector. Unplug and reconnect vacuum hose at EGR valve. For additional EGR system testing, go to TEST HE under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

EGR Vacuum Regulator (EVR) Solenoid

Turn ignition off. Disconnect EVR solenoid wiring harness connector. Measure resistance between EVR solenoid terminals. If resistance is not 26-40 ohms, replace EVR solenoid. For additional EGR system testing, go to TEST HE under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

FUEL EVAPORATION

Note. For testing of any evaporative emission system component not found here, see CIRCUIT TEST HX under SYSTEM TESTS and SYSTEM TESTS (EVAPORATIVE EMISSIONS) in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

Turn ignition off. Disconnect CV solenoid wiring harness connector. Measure resistance between CV solenoid terminals. If resistance is not 48-65 ohms, replace CV solenoid and repeat QUICK TEST. If resistance is 48-65 ohms, solenoid is okay. If fault is still present, go to CIRCUIT TEST HX in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.

EVAP Canister (All Models)

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

POSITIVE CRANKCASE VENTILATION (PCV)

1. Check PCV Valve Remove PCV valve. Shake valve and listen for rattle. If PCV valve rattles when shaken, go to next step. Replace PCV valve if it does not rattle when shaken.
2. Check PCV System Start engine and warm to normal operating temperature. Disconnect hose from remote air cleaner or outlet tube. Place a stiff piece of paper over end of hose. If vacuum from hose does not hold paper in place for one minute, repair clogged or leaking hose as necessary. If vacuum from hose holds paper in place for one minute, PCV system is okay and testing is complete.

See also:
• FUEL PRESSURE SPECIFICATIONS
• IDENTIFYING PCM GROUND PINS
• SECONDARY AIR INJECTION
• IDLE AIR CONTROL SOLENOID
• RELAYS
• CHECK FUEL PRESSURE