Engine Controls - System/component Tests - Eec-Iv: Other Ford Escort V facelift

SUPERCHARGER

Note. Supercharger cannot be overhauled. If supercharger malfunctions, replace entire supercharger assembly.

Supercharger Noisy

1. Air or vacuum leaks. Check hoses, tubes and flange joints for leaks.
2. Exhaust leaks. Check rubber tube to EGR valve for looseness and damage.
3. By-pass actuator not opening. Check by-pass vacuum tube for damage, restriction and incorrect routing. Check valve and actuator rod for restriction. Ensure actuator rod rests against lever stop when vacuum is less than 3 in. Hg. Actuator rod should be fully open (horizontal) when vacuum is greater than 8 in. Hg.
4. Low supercharger oil level. Replace supercharger if no oil is present.
5. Contaminated supercharger. Remove outlet adapter. Inspect rotors for foreign objects. Replace supercharger if rotors are damaged.
6. Gear rattle is normal and does not affect performance. Excessive gear rattle can be caused by actuator valve not opening.
7. Chirping is normal and does not affect performance. Excessive chirping can be caused by actuator valve not opening.

Low Boost

1. Air or vacuum leaks. Check hoses, tubes and flange joints for leaks.
2. Restricted air inlet. Check air filter and air induction system.
3. Supercharger not rotating. Check drive belt. Remove outlet adapter. Inspect rotors for damage and seizure. Replace supercharger if rotors are damaged.
4. By-pass actuator not closing. Check valve and actuator rod for restriction. Ensure actuator rod rests against lever stop when vacuum is less than 3 in. Hg.
5. Insufficient flow from supercharger. Remove outlet adapter. Ensure rotors turn when pulleys are rotated. Replace supercharger if rotors do not turn.

High Boost

1. Check for plugged exhaust system.
2. Check for plugged intercooler tubes.
3. Check for correct supercharger pulleys.

Oil Leakage

1. Some oil seepage may occur with mileage. Ensure PCV system is not restricted. Ensure oil fill plug is tight. Check oil level, and top off as necessary. If oil loss is excessive, replace supercharger.

Intake Manifold Runner Control Valve (Taurus SHO & Mark VIII)

With engine off, disconnect vacuum lines from both intake air valves. Apply 10 in. Hg vacuum to each air valve. Replace air valves if linkage does not respond and/or vacuum is not held.

Intake Air Control Solenoid (Taurus SHO & Mark VIII)

With engine off, wait 10 seconds, and then disconnect Intake Air Control (IAC) solenoid. Solenoid is mounted on firewall side of intake plenum. Using an ohmmeter on 200-ohm scale, check resistance between IAC solenoid terminals. Resistance should be 50-100 ohms. If resistance is not as specified, replace solenoid.

Ground Circuits

1. Using a DVOM, check for continuity to ground on PCM terminals No. 40 and 60. (Scheme 51) Resistance should be zero ohms. If resistance is not zero ohms, 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, voltmeter should indicate less than 0.5 volt. If voltmeter reading is greater than 0.5 volt, check for open circuit, corrosion and loose connection on ground lead.

Power Circuits

Using a voltmeter, check for battery voltage between PCM terminal No. 1 (KAPWR) and ground. (Scheme 51) Check for battery voltage at terminals No. 37 and 57 (VPWR). If battery voltage is not present, EEC power relay is not supplying power. See CIRCUIT TEST B in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section.

PCM Connector Terminal Identification. Scheme 51

ENGINE SENSORS & SWITCHES (PCM INPUTS)

Note. For additional sensor testing specifications, see SENSOR RANGE CHARTS article in the ENGINE PERFORMANCE Section.

A/C CUTOUT

1. Faults in system or circuits should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, See CIRCUIT TEST KM in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for testing.

AIR CHARGE TEMPERATURE (ACT) SENSOR

ACT 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 in the ENGINE PERFORMANCE Section.. For additional testing information, see CIRCUIT TEST DA in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section.

BAROMETRIC PRESSURE (BARO) SENSOR

Faults in barometric pressure sensor or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If code has not been set, see CIRCUIT TEST DF in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for sensor specifications.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

ECT 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 in the ENGINE PERFORMANCE Section.. For additional sensor circuit testing, see CIRCUIT TEST DA in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section.

EGR VALVE POSITION (EVP) SENSOR

Faults in sensor or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section, SENSOR RANGE CHARTS article in the ENGINE PERFORMANCE Section and PIN VOLTAGE CHART S article in the ENGINE PERFORMANCE Section.

EGR VACUUM REGULATOR (EVR) SOLENOID

Faults in sensor or circuit should set a service code. If service code has not been set, disconnect sensor. Measure resistance between sensor terminals. Replace sensor if resistance is not 20-70 ohms.

HEATED GAS OXYGEN SENSOR (HO2S)

Vehicle may be equipped with one or 2 HO2S sensors. They are located in exhaust pipe, upstream of catalytic converters. Faults in sensor or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, ensure none of these conditions exist

1. Moisture inside sensor/harness connector.
2. HO2S sensor coated with contaminants.
3. Sensor circuit open or shorted to ground.

If necessary, see CIRCUIT TEST H in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for additional specifications and circuit testing procedures.

INERTIA FUEL SHUTOFF (IFS) SWITCH

1. Turn ignition off. Locate IFS switch in rear of vehicle. Ensure IFS reset button is not in upper (tripped) position. Using a jumper lead, ground FP terminal at Diagnostic Link Connector (DLC). (Scheme 54)
2. Turn ignition on, leaving engine off. Leaving inertia switch connector attached, check voltage at connector. If 10.5 volts is not present, repair circuit. If 10.5 volts is present at one terminal only, replace inertia switch.
3. If 10.5 volts is present at both terminals, turn ignition off. Measure resistance between terminals on 2-wire switches. On 1.9L, measure resistance between GND and FP terminals. (Scheme 52)
4. With reset button pushed down, resistance should be 5 ohms or less. If resistance is greater than 5 ohms, replace switch. For additional circuit testing information, refer to CIRCUIT TEST J in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section.

Identifying Inertia Switch Terminals (1.9L). Scheme 52

KNOCK SENSOR (KS)

KS is located on cylinder block. Sensor is tested by substitution or by manually generating a knock to ensure sensor will set a service code. Faults in sensor or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, see CIRCUIT TEST DG in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for additional sensor circuit testing procedures.

MASS AIRFLOW (MAF) SENSOR

1. Faults in MAF sensor or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, install Breakout Box (T83L-50-EEC-IV), leaving PCM connected. Start engine, and allow it to idle.
2. On 2.3L OHC, measure voltage between test pin No. 14 and negative battery terminal. On all other models, measure voltage between test pin No. 50 and negative battery terminal. On all models, if voltage is not .36-1.50 volts, replace MAF sensor. If voltage is .36-1.50 volts, MAF sensor is okay. See CIRCUIT TEST DC in «G - TESTS W/CODES - EEC-IV (1.9L)»(ref-22814) article in the ENGINE PERFORMANCE Section for circuit testing.

POWER STEERING PRESSURE SWITCH (PSPS)

Faulty PSPS or circuit should set a diagnostic trouble code. See QUICK TEST in G - TESTS W/CODES - EEC-IV (1.9L) article in the ENGINE PERFORMANCE section. If diagnostic trouble code has not been set, see CIRCUIT TEST FF in G - TESTS W/CODES - EEC-IV (1.9L) article in the ENGINE PERFORMANCE section for testing.

PRESSURE FEEDBACK ELEC. (PFE) EGR SENSOR/DELTA PFE SENSOR

1. Faults in sensor or circuit should set a service code. If service code has not been set, install Breakout Box (014-00322). Connect PCM to breakout box. Connect hand vacuum/pressure pump to sensor. Connect DVOM to SIG RTN test terminal and ground. Monitor DVOM while applying vacuum or pressure and compare to specifications. See DELTA PRESSURE FEEDBACK ELECTRONIC (DPFE) EGR SPECIFICATIONS or PRESSURE FEEDBACK ELECTRONIC (PFE) EGR SPECIFICATIONS table. Replace sensor if not within specification.
2. The resistance substrate can be checked using an analog ohmmeter connected between VREF terminal and PFE or DPFE terminal. Exercise sensor with hand vacuum/pressure pump and watch for jerks or jumps toward infinity. No specific resistance specifications are available.

DPFE SENSOR SPECIFICATIONS

PFE SENSOR SPECIFICATIONS

THROTTLE POSITION (TP) SENSOR

Faults in TP sensor or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, see THROTTLE POSITION SENSOR (TPS) ADJUSTMENT in BASIC TESTING article in the ENGINE PERFORMANCE Section for specifications.

VEHICLE SPEED SENSOR (VSS)

1. Faults in VSS or circuit should set service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. Disconnect VSS electrical connector if service code has not been set.
2. Using DVOM, measure resistance across sensor terminals. Resistance should be 190-250 ohms. Replace sensor if not within specification. If sensor is within specification, see CIRCUIT TEST DP in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for additional circuit testing.

Constant Control Relay Module (CCRM)

Faults in CCRM or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, see CIRCUIT TEST X in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for CCRM testing.

Variable Control Relay Module (VCRM)

Faults in VCRM or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, see CIRCUIT TEST XB in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for testing.

RELAYS

Note. Fuel pump relay is located inside Integrated Relay Control Module (CCRM) on 2.3L, 3.0L & 3.8L. For CCRM test procedures, see CIRCUIT TEST X in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section.

Fuel Pump Relay

Remove relay from vehicle. Connect battery voltage to terminal "C". (Scheme 53) Ground terminal "D". 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.

Identifying Fuel Pump Relay Terminals (1.9L, 4.6L & 5.0L). Scheme 53

Air Management Solenoid

Faults in secondary air management solenoids or circuits should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, disconnect both solenoid harness connectors. Measure resistance across terminals. Resistance should be 50-100 ohms. If resistance is not as specified, replace solenoid. If resistance is as specified, see CIRCUIT TEST KC in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for additional circuit testing.

Canister Purge (CANP) Solenoid

1. Faults in CANP solenoid or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, disconnect CANP solenoid harness connector.
2. Measure resistance across CANP solenoid terminals. Resistance should be 40-90 ohms. If resistance is not as specified, replace CANP solenoid. If resistance is as specified, disconnect vacuum hose at CANP solenoid on manifold vacuum side.
3. Apply 16 in. Hg vacuum to manifold vacuum side of solenoid. CANP solenoid should hold vacuum for 20 seconds. If CANP solenoid does not hold vacuum for 20 seconds, replace CANP solenoid. If CANP solenoid holds vacuum for 20 seconds, see CIRCUIT TEST KD in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for circuit testing.

EGR Solenoid

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

Idle Air Control Solenoid

See AIR INDUCTION SYSTEMS in this article. If additional testing is required, see CIRCUIT TEST KE in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for circuit testing.

FUEL SYSTEM

Note. In following test procedures, KOEO refers to Key On Engine Off and KOER refers to Key On Engine Running.

Except 1.9L

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

1.9L

Depress retaining clips and remove rear seat cushion. Disconnect fuel pump connections. Start engine, and operate it until it stalls. Turn ignition off. Reconnect fuel pump. Install rear seat cushion.

FUEL DELIVERY

Note. For fuel system pressure testing, see BASIC TESTING article in the ENGINE PERFORMANCE Section. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article.

See RELAYS under MODULES, RELAYS & SOLENOIDS.

See MODULES under MODULES, RELAYS & SOLENOIDS.

See MODULES under MODULES, RELAYS & SOLENOIDS.

Scheme 54

1. Visually inspect fuel delivery system for leaks and damaged lines. Ensure battery is fully charged and fuses are okay. Check fuel tank contents and fuel gauge accuracy.
2. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE. Install fuel pressure gauge. Turn ignition on to activate pump. Check and record fuel pressure. For fuel pressure specifications, see «FUEL PRESSURE SPECIFICATIONS»(ref-123319) article. Proceed to appropriate step as indicated: If fuel pressure is within specification, go to step 3). If fuel pressure is zero, go to step 5). If fuel pressure is low, go to step 6). If fuel pressure is high, go to FUEL PRESSURE REGULATOR. CAUTION: Inspect fuel system for leaks and damage before testing fuel pump.
3. Check fuel injectors. See FUEL CONTROL. Start or crank engine. Using a mechanic's stethoscope, listen for regularly spaced operating clicks at each injector. If clicks are present, check fuel injectors for flow and leakage.
4. If clicks are not present, check fuel injector resistance. See FUEL CONTROL. Replace injectors not within specification. If injectors are within specification, check for 12 volts at each injector lead. If voltage is present, circuit is okay. Clean or replace injectors as necessary. If voltage is not present at injectors, see CIRCUIT TEST H in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for circuit diagnosis.
5. If fuel pressure is zero, ensure battery is fully charged. Ensure connection is okay at pump/sending unit. Turn ignition off. Using a jumper lead, ground FP terminal at Diagnostic Link Connector (DLC). (Scheme 54) Turn ignition on, leaving engine off. Listen for sound of fuel pump. If pump is running, go to next step. If pump is not running, go to step 7). (Scheme 54): Identifying Fuel Pump Connector Terminals & Circuits
6. Check condition of fuel filter. Replace filter if necessary, and repeat step 1). If filter is okay, check fuel pressure regulator. See FUEL PRESSURE REGULATOR.
7. Turn ignition off. Disconnect fuel pump/sending unit connector. 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 ignition is off and battery is fully charged. Disconnect harness connector from pump/sending unit. Ground FP terminal at DLC. Turn ignition on. Measure voltage at pump power terminal of pump/sending unit connector. If voltage is greater than 10.5 volts, replace pump/sending unit assembly. If voltage is not greater than 10.5 volts, go to next step.
9. Check inertia switch. See ENGINE SENSORS & SWITCHES (PCM INPUTS). Check fuel pump relay (if equipped). See RELAYS under MODULES, RELAYS & SOLENOIDS. Check Constant Control Relay Module (CCRM) (if equipped). See MODULES under MODULES, RELAYS & SOLENOIDS. Check engine compartment for leaks and ensure engine produces normal engine vacuum. See FUEL PRESSURE REGULATOR.

Fuel Pressure Regulator

1. Turn ignition off. Ensure vacuum hose is connected to fuel pressure regulator. Start and run engine for 10 seconds. Stop engine, and wait 10 seconds. Start and run engine for 10 seconds. Stop engine. Remove vacuum hose from pressure regulator. If fuel is present in vacuum port, replace fuel pressure regulator. If fuel is not present, go to step 2). CAUTION: Inspect fuel system for leaks and damage before testing fuel pump.
2. Connect fuel pressure gauge to Schrader valve on fuel rail. Ground FP terminal at DLC. (Scheme 54) Turn ignition on. Operate fuel pump for 30 seconds. Stop fuel pump, and check fuel pressure gauge. Ensure fuel pressure is within specification. For fuel pressure specifications, see «FUEL PRESSURE SPECIFICATIONS»(ref-123319) article.Ensure pressure does not drop greater than 2 psi (.2 kg/cm 2 ) in 3 minutes.
3. If fuel pressure is within specification, fuel pressure regulator is okay and test is compete. If fuel pressure is not within specification, check fuel filter, and service as necessary. If fuel pressure is still not within specification, install vacuum gauge to intake manifold. Start engine, and observe vacuum and fuel pressure gauge while accelerating and decelerating engine.
4. When engine is accelerating, vacuum reading should decrease and fuel system pressure should increase. When engine is decelerating, vacuum reading should increase and fuel system pressure should decrease. If readings are as indicated, fuel system is okay and test is compete.
5. If gauge readings are not as indicated, turn ignition off. Disconnect and plug fuel pressure regulator hose. Attach vacuum pump to fuel pressure regulator. Start engine. Apply vacuum to pressure regulator while observing fuel pressure gauge. If fuel pressure changes as vacuum changes, repair restriction in vacuum supply hose. If fuel pressure does not change as vacuum changes, go to step 6).
6. Ensure ignition is off. Relieve fuel pressure. Remove fuel pressure regulator. Check "O" ring, gasket and mounting surfaces for cracks, cuts and other damage. (Scheme 55) Connect vacuum pump to fuel return tube. 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.

Identifying Fuel Pressure Regulator Components. Scheme 55

Fuel Injector Check

1. Connect tachometer to engine. Run engine at idle. Disconnect and reconnect injectors individually. When disconnected, each injector should cause a momentary drop in engine speed of at least 100 RPM. Engine RPM drop should only be momentary as PCM will attempt to reestablish correct idle RPM.
2. Replace any injectors which do not cause sufficient drop in engine speed. When test is complete, check idle speed. Refer to emission control specifications on decal in engine compartment or see IDLE SPEED in the appropriate ADJUSTMENTS article in the ENGINE PERFORMANCE Section.

Fuel Injector Circuit

Disconnect injector harness connectors. Using digital ohmmeter, check connector terminal resistance of each injector. Individual injector resistance should be 13-16 ohms on all models. On non-sequential PFI engines, disconnect injector bank harness connector. Check resistance of injector bank. See INJECTOR BANK RESISTANCE table. Repair wiring or any injector not within specification.

INJECTOR BANK RESISTANCE (1)

IDLE CONTROL SYSTEM

Note. See AIR INDUCTION SYSTEMS in this article. If additional testing is required, see CIRCUIT TEST KE in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for circuit testing.

IGNITION SYSTEM

Note. For additional information and descriptions, see IGNITION SYSTEM in THEORY/OPERATION article in the ENGINE PERFORMANCE Section. Perform appropriate SPARK OUTPUT CHECK under IGNITION CHECKS in BASIC TESTING article in the ENGINE PERFORMANCE Section before entering these tests.

IGNITION SYSTEM ACRONYMS

IGNITION SYSTEM IDENTIFICATION

Preliminary Check

Perform following preliminary checks

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

No Start With Spout Conn. Disconnected (Remote Mounted ICM)

1. Ensure that SPARK OUTPUT CHECK has been performed. See IGNITION CHECKS in BASIC TESTING article in the ENGINE PERFORMANCE Section. Turn ignition on. Ensure battery has 12 volts.
2. Turn ignition off. Connect DI Diagnostic Cable (007-00097) to EEC-IV Breakout Box (T83L-50-EECIV), negative battery terminal and ICM. see scheme 6 Leave B+ lead disconnected. Ensure PIP OPEN/NORMAL/SPOUT OPEN switch is in NORMAL position. Apply DI overlay on breakout box. WARNING: DO NOT connect EEC-IV Diagnostic Cable and PCM to EEC-IV Breakout Box simultaneously.
3. Disconnect SPOUT connector. Set DVOM on A/C scale. Crank engine while measuring voltage between J7 (B --) and J15 (PIP). If voltage is 3.0-8.5 volts AC, replace ICM. If voltage is not 3.0-8.5 volts AC, connect diagnostic cable to CMP sensor and sensor connector.
4. Turn switch to PIP OPEN position. Crank engine while measuring voltage between J7 (B --) and J41 (PIP B). If voltage is 3.0-8.5 volts AC, repair open in PIP circuit between ICM and CMP sensor. If voltage is not 3.0-8.5 volts AC, check CMP wiring harness connector. If connector is okay, replace CMP sensor.

Continuous Memory Code 18 Or 212 (IDM Missing)

1. Ensure that SPARK OUTPUT CHECK has been performed. See IGNITION CHECKS in theF - BASIC TESTING article in the ENGINE PERFORMANCE Section. Turn ignition on.
2. Turn ignition off. Connect DI Diagnostic Cable (007-00097) to EEC-IV Breakout Box (T83L-50-EECIV), negative battery terminal and ICM. see scheme 6 Leave B+ lead disconnected. Ensure PIP OPEN/NORMAL/SPOUT OPEN switch is in NORMAL position.
3. Apply DI overlay on breakout box. Disconnect PCM. For CCD (Black module) equipped systems, go to step 6). For non-CCD (Gray module) equipped systems, set DVOM on DC scale. Disconnect ignition coil wiring harness connector. Turn ignition on.
4. Measure voltage between J7 (B -) at breakout box and terminal No. 4 (IDM) at PCM wiring harness connector. If voltage is greater than 5.0 volts DC, repair IDM circuit short to power between PCM and IDM 22K resistor. If voltage is less than 5.0 volts DC, turn ignition off.
5. Measure resistance between J7 (B -) at breakout box and terminal No. 4 (IDM) at PCM wiring harness connector. If resistance is less than 10,000 ohms, repair IDM circuit short to ground between PCM and IDM 22K resistor. If resistance is 10,000 ohms or more, measure resistance between J4 (COIL-) at breakout box and terminal No. 4 (IDM) at PCM wiring harness connector. If resistance is not 20,000-24,000 ohms, repair open or shorted IDM circuit.
6. Turn ignition off. Set DVOM on AC scale. Crank engine while measuring voltage between J7 (B -) at breakout box and terminal No. 4 (IDM) at PCM wiring harness connector. If voltage is greater than 1.0 volt AC, replace PCM. If voltage is not greater than 1.0 volt AC, turn ignition off.
7. Disconnect diagnostic connector from ICM. Leave ICM wiring harness connector connected to diagnostic cable. Set DVOM on DC scale. Turn ignition on. Measure voltage between J7 (B-) and J23 (IDM). If voltage is less than 0.5 volt, repair short to power in IDM circuit between PCM and ICM wiring harness connector.
8. If voltage is 0.5 volt or more, turn ignition off. Measure resistance between J7 (B-) and J23 (IDM). If resistance is less than 10,000 ohms, repair short to ground in IDM circuit between PCM and ICM wiring harness connector. If resistance is greater than 10,000 ohms, measure resistance between and J23 (IDM) and terminal No. 4 of PCM wiring harness connector. If resistance is 5 ohms or less, replace ICM. If resistance is greater than 5 ohms, repair open in IDM circuit between PCM and ICM wiring harness connector.

KOER Code 18 Or 213 (Incorrect Ignition Timing)

1. Check ignition timing. See IGNITION TIMING in BASIC TESTING article in the ENGINE PERFORMANCE Section. If ignition timing is correct, testing is complete. If ignition timing is not correct, turn ignition off.
2. Connect DI Diagnostic Cable (007-00097) to EEC-IV Breakout Box (T83L-50-EECIV), negative battery terminal and ICM. see scheme 6 Leave B+ lead disconnected. Ensure PIP OPEN/NORMAL/SPOUT OPEN switch is in SPOUT OPEN position. Apply DI overlay on breakout box.
3. Set DVOM on DC scale. Start engine and allow to idle. Measure voltage between J7 (B-) and J10 (SPOUT). If voltage is 3.0-8.5 volts, replace ICM. If voltage is not 3.0-8.5 volts, turn ignition off. Disconnect PCM wiring harness connector.
4. Disconnect diagnostic connector from ICM, Leave ICM wiring harness connector connected to diagnostic cable. Measure resistance between J10 (SPOUT) at breakout box and terminal No. 36 (SPOUT) at PCM wiring harness connector. If resistance is less than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open in SPOUT circuit between PCM and ICM wiring harness connector.

EI SYSTEM (LOW DATA RATE) (MUSTANG 2.3L)

Note. Start all diagnostics with QUICK TEST. See G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. These tests are dependent on results and service codes received during QUICK TEST. DO NOT connect PCM to EI diagnostic cable. If PCM is connected to EI diagnostic cable, PCM may be damaged. PCM 60-pin harness connector may be connected to an additional breakout box only.

Note. Refer to Figs. see scheme 12 -17 when using pinpoint test procedures.

Perform following checks

1. Inspect engine compartment to ensure all vacuum hoses and spark plug wires are properly routed and securely attached.
2. Check all wiring harness connectors for damaged pins and loose or broken conditions.
3. Ensure ICM mounting screws are tight.
4. Ensure battery is fully charged.
5. Ensure all accessories are off during diagnosis.

EI SYSTEM (LOW DATA RATE) (3.0L SHO, 3.2L & 3.8L SC)

Note. Start all diagnostics with QUICK TEST. See G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. These tests are dependent on results and service codes received during QUICK TEST.

Note. Refer to Figs. see scheme 18 -25 when using pinpoint test procedures.

Perform following checks

1. Inspect engine compartment to ensure all vacuum hoses and spark plug wires are properly routed and securely attached.
2. Check all wiring harness connectors for damaged pins and loose or broken conditions.
3. Ensure ICM mounting screws are tight.
4. Ensure battery is fully charged.
5. Ensure all accessories are off during diagnosis.

Viewing Ignition System Secondary Display

Connect engine analyzer to view parade display of ignition system secondary. While slowly increasing engine speed from idle to 2000 RPM, compare engine analyzer display to illustrations. see scheme 24 Illustrations shown are for a 4-cylinder engine but are typical for all EI engines.

EI SYSTEM (HIGH DATA RATE) - (ESCORT 1.9L & TRACER 1.9L)

Note. Start all diagnostics with QUICK TEST. See G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section before entering this test. These tests are dependent on results and service codes received during QUICK TEST.

Note. EI Diagnostic Cable (Rotunda 007-00059) should be used to diagnose this system. This cable is equipped with additional circuits and components used to enhance and modify signals for testing purposes. If an aftermarket test cable is used or diagnosis is being performed using only a DVOM, become familiar with system wiring diagram and system operation.

Note. Refer to Figs. see scheme 26 -31 when using pinpoint test procedures.

Visually inspect engine compartment to ensure all vacuum hoses and spark plug wires are properly connected. Examine all wiring harnesses and connectors for damaged insulation, burned, overheated or damaged pins, and loose or broken conditions. Check sensor shield connector. Ensure ICM mounting screw is tight. Ensure battery is fully charged and all accessories are off during diagnosis.

EI SYSTEM (HIGH DATA RATE) (3.0L FLEXIBLE FUEL)

Note. Start all diagnostics with QUICK TEST. See G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. These tests are dependent on results and service codes received during QUICK TEST.

Note. EI Diagnostic Cable (Rotunda 007-00059) should be used to diagnose this system. This cable is equipped with additional circuits and components used to enhance and modify signals for testing purposes. If an aftermarket test cable is used or diagnosis is being performed using only a DVOM, become familiar with system wiring diagram and system operation.

Note. Refer to Figs. see scheme 32 -36 when using pinpoint test procedures.

Visually inspect engine compartment to ensure all vacuum hoses and spark plug wires are properly connected. Examine all wiring harnesses and connectors for damaged insulation, burned, overheated or damaged pins and loose or broken conditions. Check sensor shield connector. Ensure Ignition Control Module (ICM) mounting screws are tight and battery is fully charged. All accessories should be off during diagnosis.

Check Base Timing

EI SYSTEM (HIGH DATA RATE - 4.6L)

Note. Start all diagnostics with QUICK TEST. See G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. These tests are dependent on results and service codes received during QUICK TEST.

Note. EI Diagnostic Cable (Rotunda 007-00059) should be used to diagnose this system. This cable is equipped with additional circuits and components used to enhance and modify signals for testing purposes. If an aftermarket test cable is used or diagnosis is being performed using only a DVOM, become familiar with system wiring diagram and system operation.

Note. Refer to Figs. see scheme 37 -41 when using pinpoint test procedures.

Visually inspect engine compartment to ensure all vacuum hoses and spark plug wires are properly connected. Examine all wiring harnesses and connectors for damaged insulation, burned, overheated or damaged pins and loose or broken conditions. Check sensor shield connector. Ensure Ignition Control Module (ICM) mounting screws are tight and battery is fully charged. All accessories should be off during diagnosis.

Air Supply Pump

Check belt tension, and adjust if necessary. Disconnect air supply hose from by-pass control valve. Start engine. If airflow is felt at pump outlet and increases as engine speed is increased, pump is okay. If airflow is not felt at pump outlet and/or does not increase as engine speed is increased, replace air supply 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 it for plugging. If no plugging or leaks are found, silencer is okay. If any plugging or leaks are found, repair or replace as necessary.

EI Block Diagram (4.6L). Scheme 56

1. Disconnect air supply hose at valve outlet. see scheme 42 Remove vacuum line from vacuum nipple. Ensure vacuum exists at vacuum line before proceeding. see scheme 42: Identifying Normally Closed Air By-Pass Valve
2. Reconnect vacuum line to vacuum nipple. With engine speed at 1500 RPM, air pump supply air should be heard and felt at air by-pass valve outlet.
3. With engine speed 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 silencer ports or at dump port.
4. If normally closed air by-pass valve does not perform as described in steps 2) and 3), check 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 valves and check valves for leaks which may be due to backflow of exhaust gases. If holes are found and/or traces of exhaust gas products are present, replace check valve.
2. Check valve should allow free flow of air in direction of arrow only. (Scheme 57) Valves should check or block free flow of exhaust gas air in 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.

Testing Air Check Valve. Scheme 57

Air Control Solenoid Valve(s)

Remove connector, and check resistance at solenoid terminals. Resistance should be 50-100 ohms when checked at coil terminals. If resistance is not 50-100 ohms, solenoid should be replaced. For additional circuit test procedures, see CIRCUIT TEST KC in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section.

Air Supply Control Valve

1. Disconnect air supply hose at inlet. Accelerate engine speed 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 58) Remove vacuum line at vacuum nipple. Accelerate engine speed to 1500 RPM. Airflow should be heard and felt at outlet "B" with little or no airflow at outlet "A".
3. Attach a hose from manifold vacuum fitting to air supply control valve vacuum nipple. Accelerate engine speed 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)-3), valve is okay. Reinstall hoses and clamps.

Air Supply Control Valve. Scheme 58

Air Control Valve (Switch-Relief)

1. Disconnect air supply hose at inlet. Accelerate engine speed to 1500 RPM, and verify presence of airflow in hose. Reconnect air supply hose to valve inlet.
2. Carefully disconnect air supply hoses at outlets "A" and "B". (Scheme 59) Carefully remove vacuum line at vacuum nipple. Accelerate engine speed 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 speed to 1500 RPM. Airflow should be heard and felt at outlet "A" with little or no airflow at outlet "B".
4. If conditions in steps 2) and 3) are not met, replace air control valve. If valve operates satisfactorily, air control valve is okay.

Identifying Air Control Valve (Switch-Relief). Scheme 59

Air Pump Resonator

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

1. Disconnect hoses from outlets "A" and "B". see scheme 46 Disconnect and plug vacuum line to port "D". With engine operating at 1500 RPM, airflow should come out of by-pass vents. see scheme 46: Identifying Combination Air By-Pass/Air Control Valve
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 speed to 1500 RPM. Airflow should come out of outlet "B". Airflow should not be detected at outlet "A".
3. Apply 8-10 in. Hg vacuum to port "S". With engine operating at 1500 RPM, airflow should come out of outlet "A". If valve is bleed-type, less air will flow from outlet "A" or "B" and main discharge will change when vacuum is applied to port "S".
4. If conditions in previous steps are not met, replace valve. If above conditions are met, valve is okay. Reconnect hoses and vacuum lines.

Thermactor Idle Vacuum (TIV) Valve

1. With engine at idle and transmission in Neutral, apply vacuum to small nipple and place fingers over TIV valve atmospheric vent holes. (Scheme 60) If vacuum is not sensed, TIV is damaged and must be replaced. If vacuum is sensed, go to next step.
2. With engine still at idle, use a vacuum pump to apply vacuum to TIV valve large nipple. See TIV VALVE (LARGE NIPPLE) VACUUM SPECIFICATIONS table. If vacuum is not held, TIV is damaged and must be replaced.

Identifying Thermactor Idle Vacuum (TIV) Valve. Scheme 60

TIV VALVE (LARGE NIPPLE) VACUUM SPECIFICATIONS

Vacuum Control Valve (VCV)

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, passage "A" to "B" should be closed and passage "A" to "C" should be open with a cold engine. (Scheme 61) With engine at normal operating temperature, VCV should be open between "A" and "B" and closed between "A" and "C".
3. For 4-port valve, check "A1" to "B1" and "A2" to "B2" separately. (Scheme 61) 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 valve.

Identifying Vacuum Control Valves. Scheme 61

Electrical Vacuum Control Valve

1. Electrical vacuum control valve may be either open or closed at room temperature, but should reverse position when engine is at normal operating temperature. While engine is cold, check for continuity across switch terminals. (Scheme 62) Note if switch is open or closed.
2. Warm engine to normal operating temperature. Check for continuity across switch terminals again. Continuity should be opposite of cold condition. If continuity does not switch, replace valve. Check vacuum function of valve. See VACUUM CONTROL VALVE (VCV) test.

Identifying Electrical Vacuum Control Valve. Scheme 62

Vacuum Check Valve

Apply 16 in. Hg vacuum to check valve. 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. Suction should be felt at valve inlet. If suction is not felt, replace valve.

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

1. Ensure all vacuum hoses are correctly routed and securely attached. Replace any crimped or broken hoses. Ensure less than one in. Hg vacuum to EGR valve exists at idle with engine at normal operating temperature. NOTE: EVR solenoid has a continuous internal leak which produces a vacuum signal of less than one 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 it in Neutral. Note idle speed. Using vacuum pump, apply 5-10 in. Hg vacuum to EGR valve. When vacuum is fully applied to EGR valve, one or more of following should occur: 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 engine does not respond as specified. 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 in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If no service code has been set, see CIRCUIT TEST DN in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for diagnostic procedures.

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.

Delta Pressure Feedback Electronic (DPFE) EGR Transducer

Faults in DPFE transducer or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, see CIRCUIT TEST DL in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section diagnostic procedures.

Pressure Feedback Electronic (PFE) EGR Transducer

Faults in PFE transducer or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If no service code has been set, see CIRCUIT TEST DL in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section 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 vacuum does not remain greater than 15 in. Hg for 10 seconds, replace valve.

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

Canister Purge Regulator (CPR) Valve

With CPR valve de-energized, apply 17 in. Hg vacuum to source port. Valve should not pass air. Apply 9-14 volts to one electrical terminal, and ground other. Valve should open and pass air. If valve does not operate as described, replace valve.

Faults in CANP solenoid or circuit should set a service code. See QUICK TEST in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If service code has not been set, see CIRCUIT TEST KD in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section for diagnostic procedures.

EVAP Canister

Canister does not have any moving parts. Check for loose, missing, cracked or broken connections and parts. Repair or replace as necessary. Canister should not contain any liquid.

PCV Valve

1. Remove PCV valve from rocker cover grommet. Shake valve. Valve should rattle when shaken. If valve does not rattle, replace valve.
2. Start engine, and warm it to normal operating temperature. On 2.3L HSC, remove corrugated hose from oil separator nipple. Place stiff piece of paper over nipple end, and wait 60 seconds. Vacuum should hold paper in place. If vacuum does not hold paper in place, replace valve.
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.