Engine Controls - System/component Tests - 2.4L 4-CYL: Other Mitsubishi Eclipse II

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 16 in. Hg. Observe operation of valve through by-pass opening.

Variable Induction Control System

VIC motor is mounted on front of intake plenum. For testing procedures, see DTC P1100 in TESTS W/CODES - 2.4L 4-CYL article.

CONTROL UNIT

Note. For Powertrain Control Module (PCM) location, see POWERTRAIN CONTROL MODULE (PCM) LOCATION table. To identify PCM power and ground terminals, see appropriate pin voltage chart in PIN VOLTAGE CHARTS - 2.4L 4-CYL article. To identify PCM power and ground circuits, see appropriate WIRING DIAGRAM in WIRING DIAGRAMS section.

Ground Circuits

1. Turn ignition off. Using an ohmmeter, check continuity between chassis ground and PCM ground terminal(s). (Scheme 46) Ohmmeter should indicate zero ohms. If reading is not as specified, check and repair open circuit between PCM connector and chassis ground. If reading is as specified, go to next step.
2. Connect voltmeter negative lead to chassis ground. Connect positive lead to PCM ground terminal(s). With engine running, voltmeter should indicate less than one volt. If reading is more than one volt, check for open, corrosion or loose connection in ground circuit.

Power Circuits

Turn ignition on. Check for battery voltage on both PCM power terminals. (Scheme 46) If battery voltage is not present, check operation of MFI relay. See RELAYS under MOTORS, RELAYS & SOLENOIDS.

POWERTRAIN CONTROL MODULE (PCM) LOCATION

Scheme 46

Scheme 47

Scheme 48

Scheme 49

ENGINE SENSORS & SWITCHES

Note. For circuit identification, see appropriate wiring diagram in WIRING DIAGRAMS section.

BAROMETRIC PRESSURE SENSOR

Sensor is a part of volume airflow sensor assembly. See TESTS W/CODES - 2.4L 4-CYL article.

CLOSED THROTTLE POSITION SWITCH

Switch is part of throttle position sensor. See CLOSED THROTTLE POSITION SWITCH or THROTTLE POSITION (TP) SENSOR in TESTS W/CODES - 2.4L 4-CYL article.

ENGINE COOLANT TEMPERATURE SENSOR

See TESTS W/CODES - 2.4L 4-CYL article.

HEATED OXYGEN SENSOR

See TESTS W/CODES - 2.4L 4-CYL article.

INTAKE AIR TEMPERATURE SENSOR

Sensor is a part of volume airflow sensor assembly. See TESTS W/CODES - 2.4L 4-CYL article.

MANIFOLD ABSOLUTE PRESSURE SENSOR

See TESTS W/CODES - 2.4L 4-CYL article.

MANIFOLD DIFFERENTIAL PRESSURE SENSOR

See TESTS W/CODES - 2.4L 4-CYL article.

Scheme 50

Scheme 51

Scheme 52

Scheme 53

1. Switch is mounted to automatic transmission, near shift lever mechanism.
2. Ensure switch is adjusted properly. Switch output can be affected by improper adjustment. On Pickup, switch is not adjustable. Go to next step.
3. On Eclipse 2.4L and Galant, ensure continuity exists between specified terminals. (Scheme 51)- (Scheme 53). If continuity is not as specified, replace switch. On all other models, go to next step.
4. Turn ignition off. Disconnect PCM connector. See «POWERTRAIN CONTROL MODULE (PCM) LOCATION»(ref-19161-S22331783042000123000000) table under COMPUTERIZED ENGINE CONTROLS. Disconnect PNP connector. Go to next step.
5. Using DVOM, check voltage between specified PNP switch connector terminal and chassis ground. See «PNP SWITCH CONNECTOR POWER SUPPLY CIRCUIT TERMINAL ID»(ref-19161-S39771745452000123000000) table. If battery voltage is present, go to next step. If voltage is less than battery voltage, check and repair circuit. PNP SWITCH CONNECTOR POWER SUPPLY CIRCUIT TERMINAL ID Application Terminal No. Summit Wagon 5
6. On Pickup, go to next step. On all other models, use a DVOM to check continuity between specified PNP switch connector and PCM connector terminal. See «PNP SWITCH-TO-PCM CIRCUIT TERMINAL ID»(ref-19161-S20376311112000123000000) table. If continuity exists go to step 7). If continuity does not exist in each circuit, check and repair faulty circuit(s) as needed. PNP SWITCH-TO-PCM CIRCUIT TERMINAL IDENTIFICATION Application PNP Switch Terminal No. PCM Terminal No. Summit Wagon 5 71 8 51
7. Check PNP switch input voltage. With PCM connector connected and PNP switch connector disconnected, turn ignition switch to ON position. Check voltage between PNP switch connector terminal No. 2 and chassis ground. If battery voltage is present, go to step 8). If voltage is less than battery voltage, check and repair circuit.
8. Turn ignition off. Reconnect PCM connector and disconnect PNP switch connector. Turn ignition on. Check voltage between specified PNP switch terminal and chassis ground. See «PNP SWITCH CONNECTOR POWER SUPPLY CIRCUIT TERMINAL ID»(ref-19161-S39771745452000123000000) table. If battery voltage is present go to step 9). If battery voltage is not present, check and repair circuit.
9. Using a DVOM, check voltage between PCM connector terminal No. 108 and chassis ground with ignition switch in START position. If voltage is less than 8 volts, check and repair circuit. If voltage is 8 volts or more, go to next step.
10. If all preceding tests do not show any system or component malfunction and PCM is suspected, substitute PCM with known-good component and retest.

POWER STEERING OIL PRESSURE (PSP) SWITCH

1. Pickup is not equipped with PSP switch. On all other models, disconnect switch connector at pump. Using DVOM, check continuity between switch and chassis ground. Continuity should not exist with wheels straight ahead and engine idling. Continuity should be present when wheels are turned to lock position or when pump pressure is increased.
2. Check continuity of circuit between switch connector and PCM connector terminal No. 107. If continuity exists, go to next step. If continuity does not exist, check and repair circuit.
3. Disconnect power steering oil pressure switch connector and PCM connector. See «POWERTRAIN CONTROL MODULE (PCM) LOCATION»(ref-19161-S22331783042000123000000) table under COMPUTERIZED ENGINE CONTROLS. Connect jumper wire between PCM terminal No. 107 and chassis ground. Using DVOM, check for continuity between switch connector and chassis ground. If continuity exists, go to next step. If continuity does not exist, check and repair circuit.
4. Turn ignition on. Using DVOM, check voltage at switch connector. If battery voltage is present, system is okay. If battery voltage is not present and PCM is suspected, substitute PCM with known-good unit and retest.

THROTTLE POSITION SENSOR

See TESTS W/CODES - 2.4L 4-CYL article.

VEHICLE SPEED SENSOR

See TESTS W/CODES - 2.4L 4-CYL article.

VOLUME AIRFLOW SENSOR

See TESTS W/CODES - 2.4L 4-CYL article.

Idle Air Control Motor

See TESTS W/CODES - 2.4L 4-CYL article.

RELAYS

MFI RELAY LOCATION

MFI Relay (Eclipse 2.4L and Galant)

1. Turn ignition off. Disconnect PCM connector. See «POWERTRAIN CONTROL MODULE (PCM) LOCATION»(ref-19161-S22331783042000123000000) table under COMPUTERIZED ENGINE CONTROLS. On Eclipse 2.4L, go to step 3). On Galant, go to step 4).
2. Turn ignition on. Using DVOM, check voltage between PCM connector terminal No. 82 and chassis ground. (Scheme 46) If battery voltage is present, go to next step. If battery voltage is not present, check and repair circuit between ignition switch and PCM connector.
3. Check voltage between PCM connector terminal No. 38 and chassis ground. If battery voltage is present, go to next step. If battery voltage is not present check and repair circuit between ignition switch and PCM connector.
4. Check voltage between PCM connector terminals No. 12 and 25 and chassis ground. Battery voltage should exist when PCM connector terminal No. 38 is grounded. If voltage is not as specified, ignition switch and PCM connector. If voltage is as specified, go to next step.
5. Turn ignition off. Check continuity between PCM connector terminals No. 13 and 26 and chassis ground. If continuity exists, go to next step. If continuity does not exist, check and repair circuits between MFI relay connector and PCM.
6. Turn ignition on. Check voltage between PCM connector terminal No. 60 on Galant or No. 80 on Eclipse and chassis ground. If battery voltage is not present, check and repair circuit between PCM and battery. If battery voltage is present, on Galant, go to step 9). On Eclipse, go to next step.
7. Remove MFI relay. Check resistance between MFI relay terminals No. 2 and 4. Resistance should be approximately 70 ohms. If continuity is not as specified, replace MFI relay. If continuity is as specified, go to next step.
8. Connect 12-volt power source between MFI relay terminals No. 4and 2. Connect positive lead to terminal No. 4. With MFI relay energized, continuity should exist between terminals No. 1 and 3. With power source removed, continuity should not exist. If continuity is not as specified, replace MFI relay. If continuity is as specified, substitute PCM with known-good unit and retest.
9. Connect 12-volt power source between MFI relay terminals No. 4and 2. Connect positive lead to terminal No. 4. With MFI relay energized, continuity should exist between terminals No. 1 and 3. With power source removed, continuity should exist between terminals No. 2 and 4. If continuity is not as specified, replace MFI relay. If continuity is as specified, substitute PCM with known-good unit and retest.

Scheme 54

Scheme 55

1. Remove MFI relay. Turn ignition on. Using DVOM, check voltage between MFI relay connector terminal No. 8 and chassis ground. (Scheme 49) If battery voltage is present, go to next step. If battery voltage is not present, check and repair circuit between ignition switch and MFI relay.
2. Turn ignition off. Using DVOM, check continuity between MFI relay connector terminal No. 6 and chassis ground. If continuity exists, go to next step. If continuity does not exist, check and repair circuit between MFI relay and chassis ground.
3. Using DVOM, check voltage between MFI relay connector terminal No. 4 and chassis ground. If battery voltage is present, go to next step. If battery voltage is not present voltage, check and repair circuit between battery and MFI relay.
4. Turn ignition off. Disconnect PCM connector. See «POWERTRAIN CONTROL MODULE (PCM) LOCATION»(ref-19161-S22331783042000123000000) table under COMPUTERIZED ENGINE CONTROLS. Using DVOM, check continuity between MFI relay connector terminal No. 3 and PCM connector terminals No. 12 and 25. (Scheme 46)and (Scheme 49). If continuity exists, go to next step. If continuity does not exist, check and repair circuit(s) between MFI relay connector and PCM.
5. Connect PCM and MFI relay connectors. Using DVOM, backprobe MFI relay connector terminal No. 2. With engine cranking, voltage should be 8 volts or more. Start and run engine at 2500 RPM or more. If battery voltage is present, go to next step. If battery voltage is not present, repair circuit between MFI relay connector and battery.
6. Remove MFI relay. Check resistance between MFI relay terminals No. 5 and 7. Resistance should be approximately 90 ohms. Check continuity between terminals No. 6 and 8. Continuity should exist in only one direction. If continuity is as specified, go to next step. If continuity is not as specified, replace MFI relay.
7. Connect 12-volt power source between MFI relay terminals No. 5 and 7. Connect positive lead to terminal No. 7. With MFI relay energized, battery voltage should exist between terminals No. 1 and 5. With power source removed, voltage should not exist. Go to next step.
8. Connect 12-volt power source to MFI relay terminals No. 6 and 8. Connect positive lead to terminal No. 8. With MFI relay energized, continuity should exist between terminals No. 2 and 4 and between terminals No. 3 and 4. With power source removed, continuity should not exist. If MFI relay does not test as specified, replace MFI relay. If relay tests okay, substitute PCM with known-good unit and retest. NOTE: Radiator cooling fan control relay for Pickup is not controlled by PCM. For circuit identification, see appropriate wiring diagram in «WIRING DIAGRAMS»(ref-19161-S13920564722000123000000) section.

Radiator Cooling Fan Control Relay (Hi & Lo)

See TESTS W/CODES - 2.4L 4-CYL article.

EGR Control Solenoid Valve

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

EVAP Purge Control Solenoid Valve

See FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS.

Variable Induction Control Solenoid Valve

See NON-TURBOCHARGED under AIR INDUCTION SYSTEMS.

FUEL DELIVERY

Note. For fuel system pressure testing, see BASIC TESTING - 2.4L 4-CYL article.

Fuel Injectors

See TESTS W/CODES - 2.4L 4-CYL article.

Pickup

1. Turn ignition off. Disconnect PCM connector. See «POWERTRAIN CONTROL MODULE (PCM) LOCATION»(ref-19161-S22331783042000123000000) table under COMPUTERIZED ENGINE CONTROLS. Go to next step.
2. Turn headlights on. Using DVOM, check voltage between PCM connector terminal No. 58 (No. 24 on Pickup) and chassis ground. If battery voltage is present, turn headlights off and go to next step. If battery voltage is not present, check and repair circuit between headlight relay connector and PCM connector.
3. Turn defogger switch on. Using DVOM, check voltage between PCM connector terminal No. 58 (No. 24 on Pickup) and chassis ground. If battery voltage is present, turn defogger switch off and go to next step. If battery voltage is not present, check and repair circuit between defogger relay connector and PCM connector.
4. Turn blower switch on. Using DVOM, check voltage between PCM connector terminal No. 58 (No. 24 on Pickup) and chassis ground. If battery voltage is present, turn blower switch off and go to next step. If battery voltage is not present, check and repair circuit between blower switch connector and PCM connector.
5. If battery voltage is present and preceding tests do not show any system or component malfunction and PCM is suspected, substitute PCM with known-good unit and retest system.

IDLE AIR CONTROL (IAC) MOTOR

For testing procedures, see TESTS W/CODES - 2.4L 4-CYL article.

IGNITION SYSTEM

Note. For basic ignition checks, see BASIC TESTING - 2.4L 4-CYL article.

Camshaft Position Sensor

See TESTS W/CODES - 2.4L 4-CYL article.

Crankshaft Position Sensor

See TESTS W/CODES - 2.4L 4-CYL article.

Knock Sensor

See TESTS W/CODES - 2.4L 4-CYL article.

1. Label and disconnect both vacuum hoses from solenoid valve. See «VACUUM DIAGRAMS - 2.4L 4-CYL.»(ref-19193) article. Disconnect electrical connector. Connect hand-held vacuum pump to solenoid valve nipple where Green-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.
3. Disconnect EGR solenoid connector. Turn ignition on. Using DVOM, check voltage at connector MFI relay power supply terminal. See «EGR CONTROL SOLENOID HARNESS CONNECTOR TERMINAL ID»(ref-19161-S14993688482000123000000) table.
4. If battery voltage is present, go to step 5). If battery voltage is not present, check and repair circuit between purge solenoid and MFI relay. If circuit is okay, inspect MFI relay. See «RELAYS»(ref-19161-S14001557562000123000000) under MOTORS, RELAYS & SOLENOIDS.
5. Disconnect PCM connector. See «POWERTRAIN CONTROL MODULE (PCM) LOCATION»(ref-19161-S22331783042000123000000) table under COMPUTERIZED ENGINE CONTROLS. Connect jumper wire between PCM terminal No. 6 and chassis ground. (Scheme 46)
6. Using DVOM, check for continuity between connector PCM control circuit terminal and chassis ground. See «EGR CONTROL SOLENOID HARNESS CONNECTOR TERMINAL ID»(ref-19161-S14993688482000123000000) table. If continuity does not exist, check and repair circuit as needed. If continuity exists and preceding tests do not show any system or component malfunction and PCM is suspected, substitute PCM with known-good unit and retest system. EGR CONTROL SOLENOID HARNESS CONNECTOR TERMINAL ID Application Terminal No. Wire Color MFI Relay Circuit 1 Black/Red PCM Control Circuit Eclipse 2 Lt. Green/Red Summit Wagon 2 Brown/Green All Other Models 2 Brown

EVAP Purge Control Valve

Remove EVAP purge control valve. Valve is mounted between canister and purge control solenoid valve. See VACUUM DIAGRAMS - 2.4L 4-CYL. article. Apply vacuum to diaphragm of vacuum valve. Valve should begin opening at approximately 15.7 in. Hg. Observe operation of valve through by-pass opening.

EVAP Purge Control Solenoid Valve (All Models)

See TESTS W/CODES - 2.4L 4-CYL article.

PCV Valve

Remove PCV valve. Shake valve by hand. Valve should rattle if moving freely. Apply air pressure to valve. Air should flow in one direction only. Connect PCV valve to vacuum hose and start engine. Ensure vacuum is flowing through valve.

MISCELLANEOUS CONTROLS

Note. Although some of the controlled devices listed here are not technically engine performance components, they can affect driveability if they malfunction.

A/C SWITCH & COMPRESSOR CLUTCH RELAY

Using DVOM, check A/C power supply voltage from PCM. Turn ignition to OFF position. Disconnect PCM connector. Turn A/C switch and ignition switch to ON positions. Check voltage between specified PCM terminals and chassis ground. See A/C POWER PCM TERMINAL IDENTIFICATION table. If battery voltage is not as present, check and repair circuit(s).

A/C POWER PCM TERMINAL IDENTIFICATION

Wiring Diagram (Eclipse 2.4L - 1 Of 2). Scheme 56

Wiring Diagram (Eclipse 2.4L - 2 Of 2). Scheme 57

Wiring Diagram (Galant 2.4L - California Emissions - 1 Of 2). Scheme 58

Wiring Diagram (Galant 2.4L - California Emissions - 2 Of 2). Scheme 59

Wiring Diagram (Galant 2.4L - Federal Emissions - 1 Of 2). Scheme 60

Wiring Diagram (Galant 2.4L - Federal Emissions - 2 Of 2). Scheme 61

Wiring Diagram (Pickup 2.4L - 1 Of 2). Scheme 62

Wiring Diagram (Pickup 2.4L - 2 Of 2). Scheme 63

Wiring Diagram (Summit Wagon 2.4L FWD - 1 Of 2). Scheme 64

Wiring Diagram (Summit Wagon 2.4L FWD - 2 Of 2). Scheme 65

Wiring Diagram (Summit Wagon 2.4L AWD - 1 Of 2). Scheme 66

Wiring Diagram (Summit Wagon 2.4L AWD - 2 Of 2). Scheme 67