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Engine Controls - System/component Tests Mitsubishi Eclipse I

Testing & Diagnostics 15 illustrations ~4502 words

INTRODUCTION

Before testing separate components or systems, perform procedures in BASIC TESTING article. Since many computer-controlled and monitored components set a trouble code if they malfunction, also perform procedures in TESTS W/CODES article.

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

AIR BY-PASS VALVE

Remove air by-pass valve. Valve is mounted to intake air duct between air-to-air intercooler and intake plenum. Apply vacuum to diaphragm of vacuum valve. Valve should begin opening at approximately 7.7 in. Hg. Observe operation of valve through by-pass opening.

WASTEGATE ACTUATOR TEST

Actuator is mounted on turbocharger. Apply pressure to wastegate actuator to ensure actuator rod moves. DO NOT apply excessive pressure to wastegate actuator or attempt to adjust wastegate valve.

WASTEGATE CONTROL SOLENOID VALVE TEST

  1. Valve is located near top of air cleaner. Disconnect harness connector at valve. Connect DVOM between Red wire terminal and ground. Turn ignition on. Battery voltage should be present. If battery voltage is not present, check for open in Red wire. Repair as necessary.
  2. If Red wire is okay, replace control relay. Control relay is located near ECU, behind radio under console. If battery voltage is present, disconnect ECU connector. Connect DVOM between Orange wire terminal of wastegate control solenoid valve and ground.
  3. Ground ECU harness connector terminal No. 105 (Orange wire). Check for open circuit or short circuit between ECU harness connect and wastegate control solenoid valve harness connector. Repair open or short to ground as necessary. If open or short does not exist, replace wastegate control solenoid valve.

CONTROL UNIT

Note. For Engine Control Unit (ECU) location, see ENGINE CONTROL UNIT (ECU) LOCATION table. To identify ECU power and ground circuits, see WIRING DIAGRAMS article.

Ground Circuits

  1. Turn ignition off. Using an ohmmeter, check continuity between chassis ground and ECU ground terminals. See «GROUND TERMINAL IDENTIFICATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Ohmmeter should indicate zero ohms. If reading is not zero ohms, repair open circuit between ECU connector and ground.
  2. Connect voltmeter negative lead to chassis ground. Connect positive lead to ECU ground terminals. See «GROUND TERMINAL IDENTIFICATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. With engine running, voltmeter should indicate less than one volt. If voltmeter reading is greater than one volt, check for open, corrosion or loose connection in ground circuit. GROUND TERMINAL IDENTIFICATION Application ECU Terminal All Models 101 & 106

Power Circuits

Turn ignition on. Check for battery voltage on ECU power terminals. See POWER TERMINAL IDENTIFICATION table. If battery voltage is not present, check operation of MPI control relay. See RELAYS under MOTORS, RELAYS & SOLENOIDS.

ApplicationECU Terminal
All Models102 & 107

POWER TERMINAL IDENTIFICATION

ApplicationLocation
EclipseForward Of Center Console Near Floor
All OthersNear Right Kick Panel

ENGINE CONTROL UNIT (ECU) LOCATION

BAROMETRIC PRESSURE SENSOR

Sensor is a part of airflow sensor assembly. See TESTS W/CODES article.

COOLANT TEMPERATURE SENSOR

  1. Remove coolant temperature sensor. Sensor is located near thermostat housing (2-wire connector). Place end of sensor in water, with terminal connector portion of sensor slightly above water.
  2. Gradually heat water, and read resistance values across terminal connectors. See «COOLANT TEMPERATURE SENSOR RESISTANCE»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If resistance is not within specification, replace sensor. COOLANT TEMPERATURE SENSOR RESISTANCE Temperature °F (°C) Ohms Eclipse 68 (20) 2200-2600 176 (80) 264-328 Galant 32 (0) 5900 68 (20) 2500 104 (40) 2700 176 (80) 300

CRANK ANGLE SENSOR

DETONATION SENSOR

EGR TEMPERATURE SENSOR (CALIFORNIA)

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

Note. On DOHC engines, idle position switch is a separate switch mounted on throttle body. On other engines, idle position switch is incorporated in idle speed control motor assembly, motor position sensor or throttle position sensor, depending on vehicle application.

IDLE POSITION SWITCH (ECLIPSE 1.8L, GALANT SOHC)

  1. Disconnect Motor Position Sensor (MPS) connector. Connect ohmmeter lead between ground and MPS connector terminal No. 4. (Scheme 12)
  2. With accelerator pedal pressed, no continuity should be present. With accelerator pedal released, continuity should be present. If switch continuity is not as specified, replace MPS.

IDLE POSITION SWITCH (ECLIPSE 2.0L DOHC, GALANT DOHC)

  1. Disconnect idle position switch single-wire connector. Check for continuity between switch terminal and switch body (ground).
  2. With accelerator pedal pressed, no continuity should be present. With accelerator released, continuity should be present. If idle position switch continuity is not as specified, replace idle position switch.

INHIBITOR SWITCH (AUTOMATIC TRANSMISSION)

Switch is mounted to automatic transaxle, near shift lever mechanism. Testing information is not available from manufacturer. See WIRING DIAGRAMS article.

Scheme 10

Scheme 10: INTAKE AIR TEMPERATURE SENSOR
Scheme 10: INTAKE AIR TEMPERATURE SENSOR

Scheme 11

Scheme 11
Scheme 11
  1. Sensor is incorporated in airflow sensor assembly inside air filter housing. Disconnect airflow sensor connector. (Scheme 10)or (Scheme 11).
  2. Measure resistance between terminals No. 6 and 8. Replace airflow sensor assembly if air temperature sensor resistance is not within specification. See «INTAKE AIR TEMPERATURE SENSOR RESISTANCE»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. INTAKE AIR TEMPERATURE SENSOR RESISTANCE Temperature °F (°C) Ohms 32 (0) 6000 68 (20) 2700 176 (80) 400 NOTE: Some engines are not equipped with Motor Position Sensor (MPS). MPS may be a separate unit mounted to throttle body or it may be incorporated in ISC motor assembly, depending on vehicle application.

Scheme 12

Scheme 12: MOTOR POSITION SENSOR (ECLIPSE 1.8L, GALANT SOHC)
Scheme 12: MOTOR POSITION SENSOR (ECLIPSE 1.8L, GALANT SOHC)
  1. Disconnect MPS connector. (Scheme 12) Connect ohmmeter lead to ground. Connect other ohmmeter lead to terminal No. 3 of sensor connector. If continuity is not present, repair wiring harness as necessary. If continuity is present, go to next step.
  2. On Eclipse 1.8L, connect ohmmeter leads to terminals No. 1 and 3. On Galant SOHC, connect ohmmeter leads to terminals No. 2 and 3.
  3. Resistance for all models should be 4000-6000 ohms. If resistance is not within specified range, replace MPS. CAUTION: DO NOT apply more than 6 volts to ISC motor.
  4. Operate ISC motor by connecting a 6-volt source directly to appropriate terminals of ISC motor connector. See «IDLE SPEED CONTROL (ISC) MOTOR OPERATION TEST»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests__idle-speed-control-isc-motor-operation) under IDLE CONTROL SYSTEM.
  5. While operating ISC motor, measure resistance between MPS connector terminals No. 1 and 2 on Eclipse 1.8L. On Galant SOHC, measure resistance between MPS connector terminals No. 3 and 5.
  6. Observe ohmmeter during ISC motor operation. If MPS resistance does not vary within a 4000-6000 ohm range or if resistance does not change smoothly, replace MPS (vehicles with separate MPS) or ISC motor assembly (vehicles with MPS incorporated in ISC).

Scheme 13

Scheme 13: OXYGEN (O2) SENSOR (2-WIRE)
Scheme 13: OXYGEN (O2) SENSOR (2-WIRE)
  1. On all models, warm engine until coolant temperature is 185-205°F (85-96°C). Disconnect O2 sensor connector. (Scheme 13)
  2. Connect digital voltmeter between terminal No. 1 and ground. Repeatedly race engine and observe O2 sensor output voltage. If output is not 0.6-1.0 volt, replace O2 sensor.

Scheme 14

Scheme 14: OXYGEN (O2) SENSOR (4-WIRE HEATED)
Scheme 14: OXYGEN (O2) SENSOR (4-WIRE HEATED)
  1. Warm engine until coolant temperature is 185-205°F (85-95°C). Disconnect O2 sensor connector. (Scheme 14) Check resistance of O2 sensor heater element. Connect ohmmeter between specified heater terminals of O2 sensor connector. See «O2 SENSOR 4-WIRE CONNECTOR TERMINAL IDENTIFICATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
  2. When O2 sensor is at 68°F (20°C), resistance should be approximately 12 ohms. If resistance is not within specification, replace O2 sensor. CAUTION: DO NOT apply battery voltage to O2 sensor output terminals; damage to O2 sensor could result.
  3. Heat O2 sensor heater element by applying battery voltage to specified heater terminals. See «O2 SENSOR 4-WIRE CONNECTOR TERMINAL IDENTIFICATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
  4. Connect digital voltmeter between specified output terminals. See «O2 SENSOR 4-WIRE CONNECTOR TERMINAL IDENTIFICATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Repeatedly race engine and observe O2 sensor output voltage. If O2 sensor output voltage is not 0.6-1.0 volt, replace O2 sensor. O2 SENSOR 4-WIRE CONNECTOR TERMINAL IDENTIFICATION Application Heater Terminals Output Terminals Eclipse & Galant 3 & 4 1 & 2

POWER STEERING OIL PRESSURE SWITCH

  1. Power steering oil pressure switch is mounted on power steering pump. Disconnect single-wire connector at switch. Start engine.
  2. Connect ohmmeter between switch terminal and ground. If continuity is present with steering wheel in straight-ahead position, replace switch. If continuity is not present while turning steering wheel, perform «POWER STEERING IDLE-UP SYSTEM TEST»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) . See «IDLE-UP SYSTEMS»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) under IDLE CONTROL SYSTEM.

Scheme 15

Scheme 15: THROTTLE POSITION SENSOR
Scheme 15: THROTTLE POSITION SENSOR
  1. TPS is mounted to throttle body, at end of throttle shaft. Disconnect TPS connector. (Scheme 15) Using ohmmeter, measure total resistance between specified TPS connector terminals. See «TPS CONNECTOR TERMINAL IDENTIFICATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If resistance is not 3500-6500 ohms, replace TPS.
  2. Using an analog (needle-type) ohmmeter, measure variable resistance between specified TPS connector terminals. See «TPS CONNECTOR TERMINAL IDENTIFICATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
  3. Operate throttle valve from closed to wide open throttle. If resistance does not change smoothly within 3500-6500 ohms throughout throttle valve movement range, replace TPS. TPS CONNECTOR TERMINAL IDENTIFICATION Application Terminal No. Total Resistance Eclipse 1.8L 1 & 2 Eclipse 2.0L 2 & 3 All Others 1 & 4 Variable Resistance Eclipse 1.8L 2 & 3 Eclipse 2.0L 3 & 4 All Others 2 & 4

Scheme 16

Scheme 16: VEHICLE SPEED SENSOR
Scheme 16: VEHICLE SPEED SENSOR

Scheme 17

Scheme 17
Scheme 17
  1. Vehicle Speed Sensor (VSS) is located in speedometer assembly. Connect an ohmmeter between sensor test terminals on back of instrument panel. (Scheme 16)or (Scheme 17).
  2. Rotate speedometer cable. For each revolution of speedometer cable, sensor should make and break continuity 4 times. If ohmmeter reading does not fluctuate between continuity and no continuity or if sensor does not make and break continuity 4 times per revolution, replace sensor.

ISC Motor

RELAYS

Note. For internal wiring diagram of MPI control relay, see WIRING DIAGRAMS article.

ApplicationLocation
GalantNear right kick panel
All OthersForward of center console

MPI CONTROL RELAY LOCATION

Scheme 18

Scheme 18: MPI Control Relay (Eclipse DOHC & Galant DOHC)
Scheme 18: MPI Control Relay (Eclipse DOHC & Galant DOHC)
  1. For relay location, see «MPI CONTROL RELAY LOCATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Check for battery voltage at terminal No. 10 of relay connector. (Scheme 18) If battery voltage is present, go to step 3). If battery voltage is not present, check circuit between relay and battery, including fusible link No. 1. Go to next step.
  2. Apply battery voltage to terminal No. 10. Battery voltage should not be present at terminals No. 4 and 5. Apply battery voltage to terminal No. 10, and ground terminal No. 8. Battery voltage should now be present at terminals No. 4 and 5.
  3. Apply battery voltage to terminal No. 3. Battery voltage should not be present at terminal No. 2. Apply battery voltage to terminal No. 3, and ground terminal No. 7. Battery voltage should now be present at terminal No. 2.
  4. Apply battery voltage to terminal No. 9. Battery voltage should not be present at terminal No. 2. Apply battery voltage to terminal No. 9, and ground terminal No. 6. Battery voltage should now be present at terminal No. 2. Replace relay if it does not test as specified.

Scheme 19

Scheme 19: MPI Control Relay (Eclipse SOHC & Galant SOHC)
Scheme 19: MPI Control Relay (Eclipse SOHC & Galant SOHC)
  1. For relay location, see «MPI CONTROL RELAY LOCATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Check for battery voltage at terminal No. 4 of relay connector. (Scheme 19) If battery voltage is present, go to step 3). If battery voltage is not present, check circuit between relay and battery, including fusible link No. 1. Go to next step.
  2. Disconnect wiring harness connector at relay. Remove relay. Check continuity, in turn, between terminal No. 4 and following: terminals No. 1, 2 and 3. If there is no continuity, go to next step. If there is continuity, replace relay.
  3. Check diode operation between terminals No. 6 and 8. If there is continuity in only one direction, go to next step. If there is no continuity in either direction or if there is continuity in both directions, replace relay.
  4. Measure resistance between terminals No. 6 and 7. If resistance is approximately 35 ohms, go to next step. If resistance is not approximately 35 ohms, replace relay.
  5. Measure resistance, in turn, between terminal No. 5 and following: terminals No. 2 and 3. In both tests, if resistance is approximately 95 ohms, go to next step. If resistance is not approximately 95 ohms, replace relay.
  6. Connect positive lead of 12-volt source to terminal No. 7 and negative lead to terminal No. 6. If there is continuity between terminals No. 1 and 4, go to next step. If there is no continuity, replace relay.
  7. Connect positive lead of 12-volt source to terminal No. 5 and negative lead to terminal No. 2. If there is continuity between terminals No. 1 and 4, go to next step. If there is no continuity, replace relay.
  8. Connect positive lead of 12-volt source to terminal No. 5 and negative lead to terminal No. 3. If there is continuity between terminals No. 1 and 4, go to next step. If there is no continuity, replace relay.
  9. Connect positive lead of 12-volt source to terminal No. 8 and negative lead to terminal No. 6. Check continuity, in turn, between terminal No. 4 and following: terminals No. 3 and 2. If continuity exists, relay is okay. If there is no continuity, replace relay.

Fuel Pressure Regulator Control Solenoid Valve (Turbo)

See FUEL DELIVERY under FUEL SYSTEM.

Fuel Injector Solenoids

See FUEL CONTROL under FUEL SYSTEM.

Wastegate Control Solenoid Valve

FUEL DELIVERY

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

  1. Label and remove vacuum hoses from solenoid valve, mounted to left end of firewall. Disconnect wiring harness. Connect a vacuum pump to nipple where Black vacuum hose was connected; leave pump connected throughout testing procedure.
  2. Apply vacuum and ensure vacuum leaks. Plug nipple where Blue-striped hose was connected. Apply vacuum and ensure vacuum holds. Remove plug from Blue-striped hose nipple. Apply battery voltage across valve terminals. Apply vacuum and ensure vacuum holds.
  3. Using an ohmmeter, check resistance across terminals of solenoid. Resistance should be 36-46 ohms at 68°F (20°C). If resistance is as specified, replace valve.

Fuel Injectors

  1. Using a stethoscope, check operating sound of injector(s) during engine cranking or idling. If clicking sound is heard, injectors are okay. If clicking sound is not heard at each injector, go to step 2).
  2. Disconnect injector electrical connector. Measure resistance between injector connector terminals. At 68°F (20°C), if resistance is not 2-3 ohms, replace injector.
  3. If resistance is within specification, check injector wiring circuit for open or short to ground. If wiring circuit tests okay, replace injector.

IDLE SPEED CONTROL (ISC) MOTOR OPERATION TEST

Note. On DOHC engines, ISC motor controls a pintle-type air by-pass valve to regulate idle air by-pass volume. On SOHC engines, ISC motor adjusts throttle plate angle to regulate idle air by-pass volume.

CAUTIONDO NOT apply more than 6 volts to ISC motor.

Eclipse 1.8L & Galant SOHC

Connect 6-volt source across terminals No. 1 and 2 of ISC motor connector. (Scheme 20) Reverse leads of 6-volt source. If motor does not operate in both directions, replace ISC motor assembly.

Scheme 20

Scheme 20: Eclipse 1.8L & Galant SOHC
Scheme 20: Eclipse 1.8L & Galant SOHC

Scheme 21

Scheme 21: Eclipse 2.0L & Galant DOHC
Scheme 21: Eclipse 2.0L & Galant DOHC
  1. Remove throttle body from intake plenum. Remove ISC motor from throttle body. Apply 6-volt source parallel to terminals No. 2 and 5 of ISC motor connector. (Scheme 21)
  2. Apply source ground lead to ISC motor connector terminals No. 3 and 6. Note slight movement of ISC motor plunger. Remove ground leads from terminals No. 3 and 6.
  3. Apply and remove source ground at terminals No. 1 and 6, 1 and 4, 3 and 4, and 3 and 6. Note slight movement of ISC motor plunger during each phase of test.
  4. Beginning at terminal No. 6, reverse grounding sequence specified in steps 2) and 3). If motor does not operate when grounding any of specified terminals, replace ISC motor.

Disconnect ISC motor connector. Connect ohmmeter between terminals No. 1 and 2 of ISC motor connector. (Scheme 20) If resistance is not 5-35 ohms at 68°F (20°C), replace ISC motor assembly.

Eclipse 2.0L & Galant DOHC

Measure resistance between terminals No. 1 and 2, 2 and 3, 4 and 5, and 5 and 6 of ISC motor connector. (Scheme 21) In each case, if resistance is not 28-33 ohms at 68°F (20°C), replace ISC motor assembly.

Scheme 22

Scheme 22: Power Steering Idle-Up System Test
Scheme 22: Power Steering Idle-Up System Test
  1. Disconnect pressure hose from power steering pump. Connect, in line, a pressure gauge and hoses capable of handling 300 psi (21 kg/cm 2 ). Also connect a shutoff valve in line with pressure gauge. (Scheme 22)
  2. Bleed air from system by disabling ignition system and cranking engine while turning steering wheel completely from left to right several times. Start engine, and turn steering wheel back and forth to raise fluid temperature to approximately 122-140°F (50-60°C).
  3. With engine idling, gradually close shutoff valve of pressure gauge to increase hydraulic pressure. If idle speed does not increase 200-250 RPM when fluid pressure reaches 213-284 psi (15-20 kg/cm 2 ), replace power steering idle-up switch.
  4. Gradually open shutoff valve. If engine speed does not return to curb idle speed between 100-142 psi (7-10 kg/cm 2 ), replace power steering idle-up switch. Remove testing equipment. Bleed air from system as described in step 2).

IGNITION SYSTEM

Note. For basic ignition checks, see BASIC TESTING article.

Crank angle sensor is located inside distributor on SOHC engines. Sensor is attached to cylinder head on DOHC engines. If malfunction occurs, Code 22 will set.

Note. Procedures are provided by manufacturer for component testing using an engine analyzer with oscilloscope capability. Refer to manufacturer's operation manual for instructions in use of oscilloscope. If using a scan tester, go to step 3.

Scheme 23

Scheme 23: Crank Angle Sensor
Scheme 23: Crank Angle Sensor

Scheme 24

Scheme 24
Scheme 24
  1. Install Test Harness (MB991348 ) between sensor and connector. On all models, using engine analyzer with oscilloscope capability, connect special patterns probe to specified connector terminal. See «CKP PATTERN PICKUP TERMINAL ID»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. CKP PATTERN PICKUP TERMINAL ID Application Terminal No. Eclipse 2.0L 2 All Other Models 3
  2. Start engine. Compare oscilloscope wave pattern with known-good wave pattern. (Scheme 23) Verify that wave length (time) decreases as engine RPM increases. If a wave pattern is output and it fluctuates to left or right, check for loose timing belt or an abnormality in sensor pickup disc. If a rectangular wave pattern is output even when engine is not started, substitute known-good CKP sensor. Repeat test. If wave pattern is still abnormal, go to step 5.
  3. Connect an engine tachometer. Crank engine. Ensure ignition coil primary current toggles on and off. Using tachometer and scan tester, compare cranking speed and scan tester read out. If engine fails to start and tachometer reads zero RPM when engine is cranked, check for broken timing belt or faulty CKP sensor. If CKP sensor is suspected, substitute known-good CKP sensor. Repeat test procedure. If engine fails to start, tachometer reads zero RPM, and ignition coil primary current fails to toggle on and off, check for faulty ignition coil, ignition circuit or power transistor. If engine starts and readouts agree, go to next step.
  4. Ensure A/C switch is in ON position to activate closed throttle position switch. Allow engine to idle. Check coolant temperature. Using scan tester, read idle speed. See «IDLE RPM SPECIFICATIONS»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If RPM is not to specification, check for faulty coolant temperature sensor, basic idle speed adjustment, or idle air control motor. If RPM is within specifications, go to next step. IDLE RPM SPECIFICATIONS Coolant Temperature Engine RPM -4°F (-20°C) Eclipse 1500-1700 Galant 1275-1475 32°F (0°C) Eclipse 1350-1550 Galant 1220-1420 68°F (20°C) Galant 1100-1300 Eclipse 1.8L 1150-1350 2.0L 1180-1380 104°F (40°C) Eclipse, Galant 950-1150 Eclipse 1.8L 950-1150 2.0L 1000-1200 176°F (80°C) Galant 600-800 Eclipse 2.0L 650-850
  5. On all models, disconnect CKP/CMP sensor connector. Turn ignition switch to ON position. Using DVOM, check voltage between chassis ground and specified CKP/CMP sensor connector terminal. See «CKP SENSOR VOLTAGE TERMINAL ID»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If battery voltage does not exist, repair ignition circuit between CKP/CMP sensor connector and Ignition switch. If battery voltage exists, go to next step. CKP SENSOR VOLTAGE TERMINAL ID Application Terminal No. Eclipse 1.8L 2 All Other Models 3
  6. With CKP/CMP sensor connector disconnected, check for continuity between chassis ground and specified CKP/CMP sensor connector terminal. See «CKP SENSOR GROUND CIRCUIT TERMINAL ID»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. CKP SENSOR GROUND CIRCUIT TERMINAL ID Application Terminal No. Eclipse 2.0L 4 Galant 2 All Other Models 1
  7. On Eclipse, go to next step. On Galant, with CKP/CMP sensor connector and ECM connector disconnected, check for continuity between specified CKP/CMP sensor connector terminal and ECM connector terminal. See «CKP TO ECM CONNECTOR TERMINAL ID»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. CKP TO ECM CONNECTOR TERMINAL ID Application CKP Terminal No. ECM Terminal No. All Models 3 69
  8. With ignition switch in ON position, check for voltage between chassis ground and specified CKP/CMP sensor connector terminal. See «CKP SENSOR SUPPLY CIRCUIT ID»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If 4.8-5.2 volts do not exist, replace ECM. If voltage is to specification and CKP sensor is suspected, replace CKP sensor. CKP SENSOR SUPPLY CIRCUIT ID Application Terminal No. Eclipse 2.0L 2 Galant 1 All Other Models 3

Detonation Sensor (2.0L Turbo)

Detonation sensor is located on block near starter. If malfunction occurs, Code 31 will set. For testing procedure, see TESTS W/CODES article.

System Testing (Federal)

  1. Disconnect Green-striped hose from throttle body, and connect vacuum pump to hose end. Plug nipple where hose was connected to throttle body. When engine is cold, 122°F (50°C) or less, and at idle, apply vacuum to disconnected hose. If idle does not change and vacuum bleeds down, system is okay.
  2. When engine is hot, 205°F (95°C), and at idle, apply 1.8 in. Hg. If idle does not change and vacuum holds, system is okay. Using a vacuum pump, apply 7.7 in. Hg. If idle becomes unstable or engine stalls (and vacuum holds), system is okay.

System Testing (California)

  1. Connect vacuum "T" fitting into Green-striped hose from EGR valve, and connect vacuum gauge to vacuum tee. When engine coolant temperature is 68°F (20°C) or less and engine is idling, snap throttle open to race engine. If no change in vacuum reading is detected on gauge, system is okay.
  2. When engine coolant temperature is 158°F (70°C) or more and engine is idling, snap throttle open to race engine. If vacuum increases to 3.9 in. Hg or higher, system is okay.
  3. Using vacuum pump, apply specified vacuum to open EGR valve. See «EGR VALVE SPECIFICATIONS»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If idle becomes unstable or engine stalls, system is okay.

EGR Control Solenoid Valve (California)

  1. Label and disconnect vacuum hoses and wiring harness from solenoid valve. For solenoid valve location, see «EGR CONTROL SOLENOID VALVE LOCATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
  2. Connect hand vacuum pump to vacuum nipple where Green striped vacuum hose was connected. Apply vacuum and ensure vacuum does not hold. Apply battery voltage to one terminal of solenoid, and ground other. Ensure vacuum holds.
  3. Using an ohmmeter, measure resistance between terminals of solenoid valve. At room temperature, reading should be 36-44 ohms. Replace solenoid if resistance is not to specification. EGR CONTROL SOLENOID VALVE LOCATION Application Location Eclipse 1.8L Right Center Of Firewall Eclipse 2.0L Left End Of Firewall Galant Near Right Shock Tower NOTE: EGR temperature sensor only determines if EGR is operating. An inoperative sensor will not affect driveability or exhaust emissions.
  1. Remove EGR temperature sensor from EGR valve. Place EGR temperature sensor in water. While increasing water temperature, measure resistance between wire terminals.
  2. At a temperature of 122°F (50°C), resistance should be 60,000-80,000 ohms. At 212°F (100°C), resistance should be 11,000-14,000 ohms. Replace EGR temperature sensor if resistance differs significantly from specification.

EGR Thermovalve (Federal)

  1. Disconnect vacuum hoses from thermovalve, and connect a hand vacuum pump to a nipple of thermovalve. For thermovalve location, see «EGR THERMOVALVE LOCATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
  2. With coolant temperature at 122°F (50°C) or less, ensure vacuum does not hold. At 176°F (80°C) or more, ensure vacuum holds. EGR THERMOVALVE LOCATION Application Location All Models Below Thermostat Housing

EGR Valve

  1. Remove EGR valve. Check valve for sticking, carbon deposits and damage. Clean valve with solvent if necessary. Apply 19.8 in. Hg to valve diaphragm. If valve does not hold vacuum, replace valve.
  2. Apply specified vacuum to valve diaphragm. See CLOSED IN. HG column in «EGR VALVE SPECIFICATIONS»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If valve begins to open before vacuum reaches specification, replace valve.
  3. Apply specified vacuum to valve diaphragm. See OPEN IN. HG column in «EGR VALVE SPECIFICATIONS»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If valve is not completely open after vacuum has reached specification, replace valve. EGR VALVE SPECIFICATIONS Application Closed In. Hg Open In. Hg Eclipse 1.8 8.5 Galant 1.7 7.5

System Test

  1. Disconnect Red-striped purge hose from throttle body, and connect it to hand vacuum pump. Plug nipple on throttle body where purge hose was removed.
  2. With engine coolant temperature at 140°F (60°C) or less and engine idling, apply 14.8 in. Hg. Ensure vacuum is held. Raise engine speed to 3000 RPM and again apply 14.8 in. Hg. Ensure vacuum is held.
  3. With engine coolant temperature at 158°F (70°C) or more and engine idling, apply 14.8 in. Hg. Ensure vacuum is held. Turn engine off. Start engine and within 3 minutes of starting engine, apply vacuum. Ensure vacuum bleeds down.
  4. With engine running for more than 3 minutes after starting, raise engine speed to 3000 RPM and apply 14.8 in. Hg. Ensure vacuum holds momentarily and then bleeds down. NOTE: In step 4), vacuum should bleed down continuously if vehicle is at an altitude of 7200 feet (2200 m) or higher, or if intake air temperature is 122°F (50°C) or higher.

Purge Control Solenoid Valve (Non-Turbo)

  1. Label and disconnect both vacuum hoses from solenoid valve. For solenoid valve location, see «PURGE CONTROL SOLENOID VALVE LOCATION»(/mitsubishi/eclipse/i-1989-1995/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Disconnect electrical connector. Connect hand vacuum pump to solenoid valve nipple where Red-striped hose was connected. Apply vacuum to solenoid valve. Vacuum should hold.
  2. Apply battery voltage to terminals of solenoid valve. Vacuum should bleed down when voltage is applied to terminals. Using an ohmmeter, check resistance across solenoid valve terminals. Reading should be 36-44 ohms at 68°F (20°C). If reading is not within specification, replace valve. PURGE CONTROL SOLENOID VALVE LOCATION Application Location Eclipse 1.8L Left Center Of Firewall All Others Right Center Of Firewall

Purge Control Solenoid Valve (Turbo)

  1. Remove Red-striped hose at purge control solenoid valve, mounted to firewall, left of master cylinder. Connect a hand vacuum pump to solenoid nipple. Apply vacuum to solenoid valve. Vacuum should not hold.
  2. Disconnect solenoid valve electrical connector. With vacuum applied to solenoid valve, apply battery voltage across connector terminals. Vacuum should hold when voltage is applied. Using an ohmmeter, check resistance across solenoid terminals. Reading should be 36-44 ohms at 68°F (20°C). If reading is not within specification, replace valve.

Purge Control Valve (Turbo)

  1. Label and disconnect vacuum hoses from purge control valve. Valve is located under battery on Eclipse and near evaporation canister on Galant. Remove purge control valve. Connect a hand vacuum pump to nipple of valve where Red-striped hose was connected (control diaphragm). Apply 15.7 in. Hg to control diaphragm. If valve does not hold vacuum, replace valve.
  2. Blow air through purge passageway (blow through side leading to purge canister). If passageway is open with no vacuum applied to control diaphragm, replace purge control valve.
  3. Connect hand vacuum pump to nipple where Black hose was connected. Apply 15.7 in. Hg to control diaphragm. If valve does not hold vacuum, replace valve.

PCV Valve

Remove PCV valve, and insert thin screwdriver into threaded end of valve to ensure plunger moves.

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