Engine Controls - Basic Testing: Other Subaru SVX I

Compression

Check engine mechanical condition using a compression gauge, vacuum gauge or engine analyzer. See engine analyzer manual for specific instructions.

Exhaust System Backpressure

1. The exhaust system can be checked with a vacuum or pressure gauge. Remove HO2S sensor or air injection check valve (if equipped).
2. Connect a 1-10 psi pressure gauge and operate engine at 2500 RPM. If exhaust system backpressure is greater than 1 3/4 - 2 psi, exhaust system or catalytic converter is plugged.
3. If a vacuum gauge is used, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold it steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restriction.

FUEL PRESSURE

Basic diagnosis of fuel system should begin by determining fuel system pressure. If fuel pump is inoperative, see appropriate test under FUEL PUMP CIRCUIT TESTS .

Relieving Fuel Pressure

1. Disconnect fuel pump connector. Crank engine for at least 5 seconds. If engine starts, let it run until it stops. Disconnect fuel hose at pressure regulator and install fuel pressure gauge using "T" connector.
2. Start engine and check fuel pressure at idle. See the «REGULATED FUEL PRESSURE»(ref-26030-S28104175782001010800000) table. Verify fuel pressure increases as engine speed increases.

REGULATED FUEL PRESSURE

IGNITION CHECKS

Note. Also see appropriate test under IGNITION CONTROL SYSTEM TESTS .

SPARK

Check for spark at spark plug wires using a spark tester. Check resistance of each spark plug wire. Replace wire if resistance is not within specification. See appropriate HIGH TENSION WIRE RESISTANCE specifications.

Note. Legacy and SVX are equipped with Direct Ignition System (DIS).

Impreza

1. Disconnect 3-wire connector from ignition coil assembly. Using an ohmmeter, check primary resistance between terminals No. 1 and 2 for one coil. (Scheme 1)
2. Check primary resistance between terminals No. 2 and 3 for remaining coil. Resistance should be as specified. See the «IGNITION COIL RESISTANCE»(ref-26030-S02593504422001010800000) table. If resistance is not as specified for each coil, replace ignition coil assembly.
3. To test secondary resistance, connect one ohmmeter lead to tower at one end of coil. Connect remaining ohmmeter lead to tower at opposite end of same coil.
4. Repeat test for other coils. If resistance of each coil is not as specified, replace ignition coil assembly.

Justy

1. Disconnect ignition coil 2-wire connector. Check primary resistance between coil terminals. See «IGNITION COIL RESISTANCE»(ref-26030-S02593504422001010800000) table. If resistance is not as specified, replace coil.
2. To check secondary resistance, connect ohmmeter between coil secondary tower and White/Black wire terminal of 2-wire connector. See «IGNITION COIL RESISTANCE»(ref-26030-S02593504422001010800000) table. If resistance is not as specified, replace coil.

Legacy

1. Disconnect 3-wire connector from ignition coil assembly. Using an ohmmeter, check primary resistance between terminals No. 1 and 2 for one coil. (Scheme 1)
2. Check primary resistance between terminals No. 2 and 3 for remaining coil. Resistance should be as specified. Refer to the «IGNITION COIL RESISTANCE»(ref-26030-S02593504422001010800000) table. If resistance is not as specified for each coil, replace ignition coil assembly.
3. To test secondary resistance, connect one ohmmeter lead to tower at one end of coil. Connect remaining ohmmeter lead to tower at opposite end of same coil.
4. Repeat test for other coils. If resistance of each coil is not as specified, replace ignition coil assembly.

Scheme 1

Loyale & SVX

Procedure is not available from manufacturer. Refer to the IGNITION COIL RESISTANCE table.

IGNITION COIL RESISTANCE - OHMS @ 68°F (20°C)

CRANKSHAFT POSITION SENSOR & TDC SENSOR SIGNALS

Note. For crankshaft position and TDC sensor signal testing, see appropriate SELF DIAGNOSTICS article.

IDLE SPEED & IGNITION TIMING

Verify idle speed and ignition timing are set to specification. Refer to the IDLE SPEED SPECIFICATIONS table and the IGNITION TIMING table. For adjustment procedures, see ADJUSTMENTS article.

IDLE SPEED SPECIFICATIONS

IGNITION TIMING (Degrees BTDC @ RPM)

1. Check Main Relay - Turn ignition off and remove main relay. Connect battery voltage to main relay terminals No. 1 and 2. Verify less than 10 ohms resistance between main relay terminals No. 3 and 5, and between terminals No. 4 and 6. If resistance is less than 10 ohms, go to next step. If resistance is more than 10 ohms, replace main relay.
2. Check ECU Power Supply Circuit - Install main relay and disconnect ECU 22-pin connector. Turn ignition on. Verify at least 10 volts between ECU 22-pin connector terminal No. 13 (Yellow/Green wire) and ground, and terminal No. 26 (Yellow/Red wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
3. Check ECU Ground Circuit - Turn ignition off. Verify less than 10 ohms harness resistance between ECU 22-pin connector terminals No. 14 (Black wire) and ground, No. 15 (Black/Yellow wire) and ground, and No. 25 (Black/Brown wire) and ground, and between 26-pin connector terminal No. 11 (Red/Green wire) and ground, and terminal No. 22 (Green/White wire) and ground. If resistance is less than 10 ohms, see IMPREZA under «IGNITION CONTROL SYSTEM TESTS»(ref-26030-S33767347892001010800000) . If resistance is more than 10 ohms, repair harness or connectors as necessary.

1. Check ECU Power Supply Circuit - Turn ignition on. Verify at least 9 volts between ECU 22-pin connector terminals No. 1 (Red wire) and ground, No. 2 (White/Blue wire) and ground, and No. 12 (Red wire) and ground. If at least 9 volts are present, go to next step. If at least 9 volts are not present, repair harness or connectors as necessary.
2. Check ECU Ground Circuit - Turn ignition off. Verify less than 10 ohms harness resistance between ECU 22-pin connector terminal No. 10 (Black/Red wire) and ground, between ECU 16-pin connector terminals No. 1 (Black/Green wire) and ground, and No. 2 (Black/Green wire) and ground, and between 26-pin connector terminals No. 1 (Black/Red wire) and ground, No. 13 (Black/Blue wire) and ground, and No. 26 (Black/Blue wire) and ground. If less than 10 ohms are present, see JUSTY under «IGNITION CONTROL SYSTEM TESTS»(ref-26030-S33767347892001010800000) . If resistance is more than 10 ohms, repair harness or connectors as necessary.

1. Check ECU Power Supply Circuit - Turn ignition on. Verify at least 10 volts between ECU 12-pin connector terminal No. 12 (Yellow wire) and ground and between ECU 22-pin connector terminals No. 2 (Yellow/Red wire) and ground, No. 13 (Yellow/Red wire) and ground, and No. 15 (Yellow/Red wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
2. Check ECU Ground Circuit - Turn ignition off. Disconnect ECU connector. Verify zero ohms between ECU 26-pin connector terminals No. 14 (Black/White wire) and ground, No. 15 (Black wire) and ground, No. 24 (Black/Yellow wire) and ground, No. 25 (Black/Yellow wire) and ground, and between ECU 22-pin connector terminals No. 11 (Black/Red wire) and ground, and No. 22 (Black/Red wire) and ground. If zero ohms are present, see LEGACY under «IGNITION CONTROL SYSTEM TESTS»(ref-26030-S33767347892001010800000) . If resistance is more than zero ohms, repair harness or connectors as necessary.

LOYALE

1. Check Ground & ECU Power Supply - Turn ignition off and disconnect ECU connector. Measure resistance between ECU harness side connector terminals No. 30 (Black/Red wire), No. 42 (Black/Red wire), No. 44 (Black wire), No. 51 (Black wire) and ground. Verify less than 10 ohms resistance between each terminal and ground. If resistance is not as specified, verify proper ground connection at right intake manifold ground terminal. Verify proper connection between body harness and engine harness connectors. Repair ground connection, harness or connectors as necessary.
2. Check ECU Power Supply Circuit - Turn ignition on (engine off). Measure voltage between ECU harness side connector terminals No. 27 (Black/White wire), No. 29 (White wire), No. 41 (White wire), No. 49 (Red/Blue wire) and ground. Verify 10 volts are present between each terminal and ground. If 10 volts are present, see LOYALE under «IGNITION CONTROL SYSTEM TEST»(ref-26030-S33767347892001010800000) . If 10 volts are not present, inspect battery terminals, fuse, ignition relay and ignition switch. Repair or replace component(s) as necessary. If components are okay, repair harness or connectors as necessary.

SVX

1. Check Operation Of Main Relay - Turn ignition on and off. Verify operating sounds from main relay. If operating sounds are present, go to step 3). If operating sounds are not present, go to next step.
2. Check Harness Connector Of Main Relay Circuit - Disconnect main relay Brown 6-pin connector. Turn ignition on. Verify at least 10 volts between main relay connector terminals No. 2 (Brown/Black wire) and ground, No. 4 (Blue/Red wire) and ground, and No. 5 (Yellow wire) and ground. If 10 volts are not present, repair harness or connectors as necessary. If main relay harness is okay, replace main relay. Turn ignition off and connect main relay harness connector.
3. Check ECU Power Supply Circuit - Turn ignition off and disconnect ECU Yellow 22-pin connector. Turn ignition on. Verify at least 10 volts between connector terminals No. 2 (White/Red wire) and ground, and No. 13 (White/Red wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
4. Check ECU Ground Circuit - Verify zero ohms resistance between ECU 22-pin connector terminals No. 11 (Black/Red wire) and ground, and No. 22 (Black/Blue wire) and ground, and between ECU 26-pin connector terminals No. 14 (Black/White wire) and ground, No. 15 (Black wire) and ground, No. 24 (Blue/Black wire) and ground, and No. 25 (Black/Yellow wire) and ground. If zero ohms are present, see SVX under «IGNITION CONTROL SYSTEM TESTS»(ref-26030-S33767347892001010800000) . If resistance is more than zero ohms, repair harness or connectors as necessary.

1. Check Ignition System For Proper Spark - Remove injector sub-harness and plug wire cap from each spark plug. Install a known good spark plug to plug wire and position spark plug so it is grounded to engine. Verify each spark plug has a spark as engine is turned over. If a spark does not occur at each spark plug, connect injector sub-harness and plug wires and go to next step. If a spark does occur at each spark plug, see IMPREZA under «FUEL PUMP CIRCUIT TESTS»(ref-26030-S11960652292001010800000).
2. Check Ignition Coil Power Supply Circuit - Turn ignition off and disconnect Gray 3-pin ignition coil connector. Turn ignition on. Verify at least 10 volts between ignition coil connector terminal No. 2 (Blue/Red wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
3. Check Ignition Coil - Verify.7 ohm resistance between ignition coil connector terminals No. 1 and 2, and No. 2 and 3. Verify 13,800 ohms resistance between spark plug wire towers opposite each other. If specified resistance is present, go to next step. If specified resistance is not present, replace ignition coil. (Scheme 1)
4. Check Harness Connector Between Ignition Coil & Ignitor - Turn ignition off and disconnect Gray 6-pin ignitor connector. Measure harness resistance between ignition coil connector terminal No. 1 (Blue/Red wire) and ignitor connector terminal No. 5 (Blue wire), and between coil connector terminal No. 3 (Red/Green wire) and ignitor connector terminal No. 6 (Red/Green wire). If resistance is less than 10 ohms, go to next step. If resistance is more than 10 ohms, repair or replace harness connector as necessary.
5. Check Input Signal For Ignitor - Turn ignition off and connect ignition coil and ignitor connectors. Measure voltage between ignitor 6-pin connector terminal No. 1 (Yellow/Blue wire) and ground, and between terminal No. 2 (Green/White wire) and ground. Crank engine and verify voltage fluctuates between.1-3.4 volts. If voltage fluctuates, go to next step. If voltage does not fluctuate, replace ignitor.
6. Check Ignitor Harness Connector Ground Circuit - Turn ignition off. Verify less than 10 ohms resistance between ignitor connector terminal No. 3 (Black wire) and ground. If resistance is as specified, go to next step. If resistance is not as specified, repair harness or connectors as necessary.
7. Check Harness Connector Between ECU & Ignitor - Turn ignition off. Disconnect ECU 26-pin and 22-pin Green connectors. Verify less than 10 ohms resistance between ECU connectors and ignitor connector. Measure between 22-pin connector terminal No. 20 (Green/White wire) and ignitor connector terminal No. 2 (Green/White wire), and between terminal No. 21 (Yellow/Blue wire) and terminal No. 1 (Yellow/Blue wire). On ECU 26-pin connector, measure between terminal No. 14 (Black wire) and ignitor 6-pin connector terminal No. 3 (Black wire). Verify one megohm resistance between 22-pin connector terminal No. 20 (Green/White wire) and ground, terminal No. 21 (Yellow/Blue wire) and ground, and 26-pin connector terminal No. 14 (Black wire) and ground. If harness resistance is not as specified, repair harness or connectors as necessary. If harness resistance is as specified, inspect and repair ECU connectors. If ECU connectors are okay, replace ECU.

1. Check Ignition System For Proper Spark - Remove injector sub-harness and plug wire cap from each spark plug. Install a known good spark plug to plug wire and position spark plug so it is grounded to engine. Verify each spark plug has a spark as engine is turned over. If a spark does not occur at each spark plug, connect injector sub-harness and plug wires and go to next step. If a spark does occur at each spark plug, see JUSTY under «FUEL PUMP CIRCUIT TESTS»(ref-26030-S11960652292001010800000).
2. Check ignition Power Circuit - Disconnect ignition coil 2-pin (Black) connector and igniter 4-pin (Gray) connector. Turn ignition on. Measure voltage between harness side of ignition coil connector terminal No. 1 (White/Black wire) and ground. Measure voltage between harness side of igniter connector terminal No. 3 (White/Black wire) and ground. Turn ignition off. If voltage is greater than 9 volts, go to next step. If voltage is less than 9 volts, repair harness or connectors as necessary. (Scheme 2)
3. Check Ignition Coil - Remove coil wire from ignition coil. Measure resistance between ignition coil 2-pin (Black) connector terminals No. 1 (White/Black wire) and No. 2 (Yellow/Blue wire). At 68°F (20°C), resistance should be.9-1.1 ohms. If resistance is not as specified, replace coil. Measure resistance between ignition coil 2-pin (Black) connector terminal No. 1 (White/Black wire) and center coil wire fitting on coil. At 68°F (20°C), resistance should be 10,000-14,000 ohms. If resistance is not as specified, replace coil. If resistance is as specified, go to next step.
4. Check Harness Between Igniter & Ignition Coil - Measure resistance between igniter 4-pin (Gray) connector terminal No. 4 (Yellow/Blue wire) and ignition coil 2-pin (Black) connector terminal No. 2 (Yellow/Blue wire). If resistance is less than one ohm, connect all connectors and go to next step. If resistance is greater than one ohm, repair harness or connectors as necessary.
5. Check Ignition System Using Self-Diagnostic System - Disconnect test mode connector and read memory connector. Crank engine for at least 5 seconds without starting. Turn ignition on and connect read memory connector. Verify trouble code 36 is stored and go to next step. If trouble code 36 is not stored, continue inspection according to trouble code(s) stored.
6. Check Crankshaft Position Sensor Harness - Disconnect distributor (Gray) connector. Using a high-impedance voltmeter set below.5 volt range, measure voltage between distributor connector terminals No. 1 (Red wire) and No. 2 (White wire) while cranking engine. Voltage should change in response to engine RPM. If voltage does not change, verify harness continuity. Repair harness or connectors as necessary. If harness is okay, replace crankshaft position sensor. If voltage changes in response to engine RPM, turn ignition off and disconnect ECU 26-pin connector. Measure harness resistance between ECU connector and distributor connector terminals. Refer to the «ECU-TO-DISTRIBUTOR HARNESS RESISTANCE (JUSTY)»(ref-26030-S27524757622001010800000) table. If harness resistance is not as specified, replace harness. If harness resistance is as specified, connect ECU connector. Measure resistance between ECU connector terminal No. 7 and ground. If resistance is not less than 10 ohms, replace ECU.

ECU-TO-DISTRIBUTOR HARNESS RESISTANCE (JUSTY)

1. Check Ignition System For Proper Spark - Remove injector sub-harness and plug wire cap from each spark plug. Install a known good spark plug to plug wire and position spark plug so it is grounded to engine. Verify each spark plug has a spark as engine is turned over. If a spark does not occur at each spark plug, connect injector sub-harness and plug wires and go to next step. If a spark does occur at each spark plug, see LEGACY under «FUEL PUMP CIRCUIT TESTS»(ref-26030-S11960652292001010800000).
2. Check Voltage At Ignition Coil Positive Terminal - Turn ignition on. Verify at least 10 volts between ignition coil 3-pin connector terminal No. 2 (Yellow/Red wire) and ground. If voltage is as specified, go to next step. If voltage is not as specified, repair harness or connectors as necessary.
3. Check Ignition Coil - Remove ignition coil connector and remove ignition coil. Measure resistance of ignition coil primary and secondary windings. If resistance is as specified, go to next step. If resistance is not as specified, replace coil. On primary side, verify.7 ohm resistance between 3-pin connector terminal No. 2 (Yellow/Red wire) and plug wire coil tower No. 1 or 3 (closest to 3-pin connector). On secondary side Hitachi coil, verify 13,800 ohms resistance between plug wire coil towers No. 1 and 2, and No. 3 and 4. On secondary side Diamond coil, verify 21,000 ohms between plug wire coil towers No. 1 and 2, and No. 3 and 4. (Scheme 1)
4. Check Ignitor Output Signal - Connect all connectors. Measure voltage between ignitor output connector terminal No. 1 (Yellow/Blue wire) and ground, and terminal No. 2 (Green/White wire) and ground while cranking engine. If at least.1 volt is present, go to next step. If at least.1 volt is not present, replace ignitor.
5. Check Harness Between ECU & Ignitor - Turn ignition off and disconnect ECU and ignitor connectors. Verify zero ohms between ECU connector terminal No. 9 (Green/White wire) and ignitor terminal No. 2, ECU connector terminal No. 10 (Yellow/Blue wire) and ignitor terminal No. 1, ECU connector terminal No. 15 (Black wire) and ignitor terminal No. 3 (Black wire) and ground. Verify no continuity between ignitor terminal No. 1 (Yellow/Blue wire) and ground, and between ignitor terminal No. 2 (Green/White wire) and ground. If resistance is as specified, inspect ECU connector and repair as necessary. If ECU connector is okay, replace ECU. If resistance is not as specified, repair harness or connectors as necessary.

1. Check Ignition Control System - Turn ignition off and connect ECU connectors. Disconnect fuel injector connector. Using a timing light, verify ignition spark when cranking engine. If ignition spark is present, refer to LOYALE under «FUEL PUMP CIRCUIT TEST»(ref-26030-S11960652292001010800000) . If ignition spark is not present, go to next step.
2. Check Crankshaft Position Sensor Harness I - Disconnect crankshaft position sensor connector at distributor. Turn ignition on. Verify more than 10 volts between crankshaft position sensor connector Green/Black wire and ground. If voltage measured is greater than 10 volts, go to next step. If voltage measured is less than 10 volts, verify more than 10 volts at ECU terminal No. 19 (Green/Black wire). If more than 10 volts are present, repair harness or connectors as necessary. If more than 10 volts are not present, replace ECU.
3. Check Crankshaft Position Sensor Harness II - With ignition turned on, verify more than 4 volts between crankshaft position sensor connector Black/White wire and ground, and Green/Yellow wire and ground. If more than 4 volts are present, connect crankshaft position sensor connector and go to next step. If voltage is less than 4 volts, verify more than 4 volts between ECU connector terminals No. 21 (Black/White wire) and ground, and No. 20 (Green/Yellow wire) and ground. If voltage is more than 4 volts, repair harness or connectors as necessary. If voltage is less than 4 volts, replace ECU.
4. Check Crankshaft Position Sensor Signal - Disconnect 2-pin ignition coil power transistor connector. Turn ignition on. Slowly turn crankshaft without using starter. Verify voltage change repeats from zero to 5 volts between ECU position signal terminal No. 21 (Black/White wire) and ground. If voltage does not change, replace crankshaft position sensor. If voltage changes, verify voltage change repeats from zero to 5 volts between ECU reference signal terminal No. 20 (Green/Yellow wire) and ground. If voltage does not change, replace crankshaft position sensor. If voltage changes, connect 2-pin ignition coil power transistor connector and go to next step.
5. Check Ignition Coil Power Transistor - Connect injector connector and turn ignition on. Verify more than 10 volts between ignition coil power transistor 2-pin terminal White/Yellow wire and ground. If less than 10 volts is present, repair harness or connectors as necessary. If voltage is more than 10 volts, verify more than 10 volts between ignition coil negative terminal and ground. If voltage is less than 10 volts, replace ignition coil. If voltage is more than 10 volts, disconnect 2-pin ignition coil power transistor connector. Monitor voltage change between 2-pin signal terminal White/Yellow wire at ignition coil power transistor and ground while cranking engine. If voltage changes while engine is cranking, replace ignition coil. If voltage does not change while engine is cranking, repair harness or connectors as necessary.

1. Check ECU Output Signal - Measure voltage between ECU 26-pin Yellow connector terminals and ground. While cranking engine, verify at least 5 volts at each terminal. See «ECU OUTPUT SIGNAL»(ref-26030-S22060535512001010800000) table. If at least 5 volts are present, go to next step. If at least 5 volts are not present, inspect ECU connector terminal for damage and/or proper connection. If ECU connector is okay, inspect crankshaft position sensor No. 1 and 2, and camshaft position sensor. ECU OUTPUT SIGNAL ECU Terminal No. Wire Color Engine Cylinder No. 10 (1) (BLU Wire) 1 8 (1) (BLU/WHT Wire) 2 9 (1) (BLU/BLK Wire) 3 7 (1) (BLU/RED Wire) 4 21 (1) (BLU/YEL Wire) 5 16 (1) (BLU/GRN Wire) 6 (1) Yellow ECU 26-pin connector.
2. Check Harness Between ECU & Ignitor - Turn ignition off and disconnect ECU and ignitor connectors. Measure harness resistance between ECU 26-pin Yellow connector terminals and ignitor 7-pin Gray connector terminals, and between ignitor connector terminal No. 4 (Black wire) and ground. Refer to the «ECU & IGNITOR HARNESS RESISTANCE»(ref-26030-S05397017662001010800000) table. If zero ohms resistance is present, go to next step. If zero ohms resistance is not present, repair harness or connectors as necessary. ECU & IGNITOR HARNESS RESISTANCE ECU Terminal No. Ignitor Terminal No. Engine Cylinder No. 10 (BLU Wire) 7 (BLU Wire) 1 8 (BLU/WHT Wire) 6 (BLU/WHT Wire) 2 9 (BLU/BLK Wire) 5 (BLU/BLK Wire) 3 7 (BLU/RED Wire) 3 (BLU/RED Wire) 4 21 (BLU/YEL Wire) 2 (BLU/YEL Wire) 5 16 (BLU/GRN Wire) 1 (BLU/GRN Wire) 6
3. Check Ignitor Output Signal - Connect all connectors. Measure voltage between each ignitor output connector terminal and ground while cranking engine. If at least 5 volts are present, go to next step. If at least 5 volts are not present, replace ignitor.
4. Check Harness Connector Between Ignitor & Each Ignition Coil - Turn ignition off. Disconnect ignitor 6-pin Gray connector and each ignition coil connector. Verify resistance between ignitor connector terminal and each ignition coil connector terminal. See the «IGNITOR & COIL HARNESS RESISTANCE»(ref-26030-S05139168602001010800000) table. If zero ohms resistance is present, go to next step. If zero ohms resistance is not present, repair or replace harness or connectors as necessary. IGNITOR & COIL HARNESS RESISTANCE Ignitor Term. No. Ignition Coil Term. No. Engine Cylinder No. 1 (GRN/RED Wire) 2 (GRN/RED Wire) 1 2 (GRN/WHT Wire) 2 (GRN/WHT Wire) 2 3 (GRN/BLK Wire) 2 (GRN/BLK Wire) 3 4 (GRN Wire) 2 (GRN Wire) 4 5 (GRN/BLU Wire) 2 (GRN/BLU Wire) 5 6 (GRN/YEL Wire) 2 (GRN/YEL Wire) 6
5. Check Ignition Coil Power Supply Circuit - Connect all connectors and turn ignition on. Verify 12 volts between each ignition coil connector terminal No. 1 (Black/White wire) and ground. If 12 volts are present, go to next step. If 12 volts are not present, repair harness or connectors as necessary.
6. Check Ignition System For Spark Using A New Coil - Turn ignition off and remove each ignition coil from cylinder head. Replace each ignition coil with a known good one. Verify a spark occurs at each cylinder. If a spark occurs, see SVX under «FUEL PUMP CIRCUIT TESTS»(ref-26030-S11960652292001010800000) . If spark does not occur, replace spark plug(s).

1. Check Fuel Pump Operation - Verify fuel pump operation for 2 seconds after turning ignition on. If fuel pump operates for 2 seconds, check fuel injector circuit. See IMPREZA under «FUEL INJECTOR CIRCUIT TESTS»(ref-26030-S08383405292001010800000). If fuel pump does not operate, go to next step.
2. Check Fuel Pump Ground Circuit - Turn ignition off and disconnect fuel pump 6-pin connector. Verify less than 10 ohms resistance between connector terminal No. 3 and ground. If resistance is less than 10 ohms, go to next step. If resistance is more than 10 ohms, repair harness or connectors as necessary.
3. Check Fuel Pump Power Supply - Turn ignition on. Verify at least 10 volts between fuel pump 6-pin connector terminal No. 1 (Blue/Yellow wire) and ground. If at least 10 volts are not present, go to next step. If at least 10 volts are present, replace fuel pump.
4. Check Harness Resistance Between Fuel Pump & Fuel Pump Relay - Turn ignition off. Verify less than 10 ohms resistance between fuel pump connector terminal No. 1 (Blue/Yellow wire) and fuel pump relay 4-pin connector terminal No. 4 (Black/Red wire). If resistance is less than 10 ohms, go to next step. If resistance is more than 10 ohms, repair harness or connectors as necessary.
5. Check Fuel Pump Relay - Disconnect fuel pump relay 4-pin connector and main relay 6-pin connector. Remove fuel pump relay and main relay with bracket. Connect battery voltage to fuel pump relay terminals No. 1 and 3. Verify less than 10 ohms resistance between terminals No. 2 and 4. If resistance is less than 10 ohms, go to next step. If resistance is greater than 10 ohms, replace fuel pump relay. (Scheme 2)
6. Check Harness Resistance Between ECU & Fuel Pump Relay - Disconnect ECU connectors. Verify less than 10 ohms resistance between ECU 26-pin connector terminal No. 8 (Light Green/Black wire) and fuel pump relay connector terminal No. 3 (Light Green/Black wire). If more than 10 ohms is present, repair harness or connectors as necessary. If less than 10 ohms is present, inspect ECU connector terminal. If ECU connector is okay, replace ECU.

Scheme 2

1. Check Fuel Pump Operation - Verify fuel pump operation for 2 seconds after turning ignition on. If fuel pump operates for 2 seconds, check fuel injector circuit. See JUSTY under «FUEL INJECTOR CIRCUIT TESTS»(ref-26030-S08383405292001010800000) . If fuel pump does not operate, go to next step.
2. Check Fuel Pump Relay Operation - Disconnect fuel pump relay connector and remove fuel pump relay from bracket. Measure resistance of relay coil connector terminals No. 1 (Blue/Black wire) and No. 3 (Red wire). Fuel pump relay is okay if resistance is 60-80 ohms at 68°F (20°C). Measure resistance between fuel pump relay terminals No. 2 and 4. There should be no continuity. Connect battery voltage between fuel pump relay terminals No. 1 and 3. Measure resistance between fuel pump relay terminals No. 2 and 4. Resistance should be less than one ohm. If resistance is not as specified, replace fuel pump relay. If resistance is as specified, install fuel pump relay on bracket, connect fuel pump connector and go to next step.
3. Check Fuel Pump Relay Power Line Circuit - Turn ignition on. Measure voltage between fuel pump relay connector terminal No. 3 (Red wire) and ground. If 9 volts are present, go to next step. If 9 volts are not present, repair harness or connectors as necessary.
4. Check Voltage Between ECU 26-Pin Connector & Ground - Turn ignition on for 2 seconds and measure voltage between ECU 26-pin connector terminal No. 18 (Blue/Black wire) and ground. Voltage should be 2.5 volts while ignition is on. After 2 seconds, turn ignition off and measure voltage. Voltage should be 9 volts. If voltage readings are as specified, go to next step. If voltage readings are not as specified, check ECU harness, connector and ground wire. Repair harness or connectors as necessary. If harness and connectors are okay, replace ECU.
5. Check Voltage At Fuel Pump Terminal - Disconnect fuel pump/gauge connector. Turn ignition on for 2 seconds and measure voltage between fuel pump/gauge connector terminal No. 2 and ground. If voltage is greater than 9 volts, go to next step. If voltage is less than 9 volts, repair harness or connectors as necessary.
6. Check Fuel Pump Operation - Connect battery voltage to fuel pump/gauge connector terminal No. 2 and a jumper wire from fuel pump/gauge connector terminal No. 1 to ground. If fuel pump operates, repair fuel pump/gauge ground circuit. If fuel pump does not operate, repair fuel pump.

1. Check Fuel Pump Operation In D-Check Mode - Connect test mode connector and turn ignition on. Verify fuel pump operation for 2 seconds after turning ignition on. If fuel pump operates for 2 seconds, check fuel injector circuit. See LEGACY under «FUEL INJECTOR CIRCUIT TESTS»(ref-26030-S08383405292001010800000) . If fuel pump does not operate, go to next step.
2. Check Fuel Pump Relay - Disconnect fuel pump relay connector and remove fuel pump relay from bracket. Verify 70 ohms of resistance between fuel pump relay terminals No. 1 and 3. Replace fuel pump relay if resistance is not as specified. If resistance is okay, connect positive battery voltage to terminal No. 1 and negative lead to terminal No. 3. If fuel pump relay does not click, replace it. If fuel pump relay clicks, verify zero ohms resistance between terminals No. 2 and 4. If resistance is as specified, go to next step. If resistance is not as specified, replace fuel pump relay.
3. Check Voltage Between Fuel Pump Relay & Ground - Turn ignition off. Remove fuel pump relay without disconnecting connector. Verify at least 10 volts between fuel pump relay connector terminal No. 1 (Yellow wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair power harness or connector.
4. Check Voltage Between ECU & Ground - Turn ignition on. Verify at least 10 volts when ignition is on and zero volts while cranking engine. Measure voltage between ECU 26-pin connector terminal No. 23 (Light Green/Blue wire) and ground. If voltage is as specified, go to next step. If voltage is not as specified, repair faulty connector or ground circuit. If connector and ground are okay, replace ECU.
5. Check Fuel Pump Terminal Voltage - Remove fuel pump access cover located in trunk area and remove fuel pump connector. Verify at least 10 volts between 5-pin fuel pump connector terminal No. 1 (Brown wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors between fuel pump and fuel pump relay as necessary.
6. Check Fuel Pump Operation - Disconnect fuel pump connector. Connect battery positive voltage lead to terminal No. 1 and battery negative voltage lead to terminal No. 3. If fuel pump operates, repair fuel pump grounding circuit. If fuel pump does not operate, replace fuel pump.

1. Check Fuel Injection Operation - Connect injector connector and disconnect ignition coil power transistor 2-pin connector. Remove air intake duct from throttle body. Crank engine and visually verify that fuel is injected into throttle body. If fuel is not injected, go to next step. If fuel is injected, go to step 3).
2. Check Fuel Pump Operation - Install upper duct. Verify fuel pump operation while cranking engine. If fuel pump operates, refer to LOYALE under «FUEL INJECTOR CIRCUIT TESTS»(ref-26030-S08383405292001010800000) . If fuel pump does not operate, verify fuel pump relay operation when ignition is turned on and off. If fuel pump relay operates, verify voltage to fuel pump during engine cranking. If voltage is not supplied to fuel pump, repair fuel pump power circuit harness. If voltage is supplied to fuel pump, verify less than 10 ohms resistance between fuel pump connector ground terminal and ground. If more than 10 ohms is present, repair fuel pump ground circuit harness. If less than 10 ohms is present, replace fuel pump. If fuel pump relay does not operate when ignition is turned on and off, verify more than 10 volts between fuel pump relay terminal Blue/Black wire of ECU connector and ground while cranking engine. If more than 10 volts are not present, replace ECU. If more than 10 volts are present, turn ignition off. Verify less than 100 ohms resistance between fuel pump relay terminal Blue/Black wire of ECU connector and ground. If resistance is greater than 100 ohms, repair harness or connectors as necessary. If resistance is less than 100 ohms, replace fuel pump relay.
3. Check ECU & Throttle Sensor Circuit - Install air intake duct and connect ignition coil power transistor 2-pin connector. Turn ignition off and disconnect ECU connector. Verify 3.5-6.5 ohms resistance between ECU connector terminals No. 26 (Red wire) and No. 35 (Black wire). Measure resistance between ECU connector terminals No. 25 (White wire) and No. 35 (Black wire) while throttle is closed and opened. Resistance should be less than 1000 ohms when throttle is fully closed and greater than 2400 ohms when throttle is fully open. If resistance is as specified, go to next step. If resistance is not as specified, disconnect throttle 4-pin connector. Verify resistance between throttle 4-pin connector, on sensor side, terminals "B" (Black wire) and "D" (Red wire) is 3.5-6.5 ohms. Measure resistance between connector terminals "C" (Green wire) and "B" (Black wire) while throttle is closed and opened. Resistance should be less than 1000 ohms when throttle is fully closed and greater than 2400 ohms when throttle is fully open. If resistance is as specified, repair harness or connectors as necessary between ECU and throttle position sensor. If resistance is not as specified, replace throttle position sensor.
4. Check Coolant Temperature Sensor Signal Circuit - Verify 100-20,000 ohms resistance between ECU connector terminal No. 23 (White/Black wire) and ground. If resistance is not as specified, go to next step. If resistance is as specified, turn ignition on. Verify fuel pressure of 20-24 psi (1.4-1.7 kg/cm 2 ). If fuel pressure is not as specified, replace fuel pressure regulator. If fuel pressure is as specified, replace ECU.
5. Check Coolant Temperature Sensor - Disconnect coolant temperature sensor connector. Verify resistance is 100-20,000 ohms between sensor connector terminals. If resistance is as specified, repair harness or connectors as necessary. If resistance is not as specified, replace coolant temperature sensor.

1. Check Fuel Pump Operation In D-CHECK Mode - Connect test mode terminal. Turn ignition on. Verify proper fuel pump operation. If fuel pump operates properly, go to next step. If fuel pump does not operate properly, refer to SVX under «FUEL INJECTOR CIRCUIT TESTS»(ref-26030-S08383405292001010800000) .
2. Check Fuel Pump Relay - Disconnect fuel pump relay connector and remove fuel pump relay from bracket. Verify 70 ohms of resistance between fuel pump relay terminals No. 1 and 3. Replace fuel pump relay if resistance is not as specified. If resistance is okay, connect battery voltage positive lead to terminal No. 3 and negative lead to terminal No. 1. If fuel pump relay does not click, replace it. If fuel pump relay clicks, verify zero ohms resistance between terminals No. 2 and 4. If there is zero ohms resistance, go to next step. If there is resistance measured, replace fuel pump relay.
3. Check Power Supply To Fuel Pump Relay - Turn ignition off and connect fuel pump relay. Turn ignition on and measure voltage between fuel pump relay connector terminal No. 3 and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
4. Check Input Signal For ECU - Turn ignition on. Verify at least 10 volts between ECU 26-pin connector terminal No. 23 (Green/Black wire) and ground. Crank engine while measuring voltage. Verify zero volts between ECU 26-pin connector terminal No. 23 (Green/Black wire) and ground. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6).
5. Check Harness Connector Between ECU & Fuel Pump - Turn ignition off. Disconnect ECU 26-pin harness connector and fuel pump relay 4-pin harness connector. Verify zero ohms resistance between ECU connector terminal No. 23 and fuel pump relay connector No. 3 (Green/Black wire). Verify at least one ohm resistance between fuel pump relay terminal No. 3 (Green/Black wire) and ground. If resistance is not as specified, repair harness or connectors as necessary. If resistance is as specified, inspect ECU connector terminal and repair as necessary. If ECU connector is okay, replace ECU.
6. Check Voltage For Fuel Pump - Fold down rear seat back and turn up floor mat. Remove fuel pump access hole cover. Disconnect fuel pump connector. Verify at least 10 volts between fuel pump connector terminal No. 1 (Blue wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors between fuel pump relay and fuel pump as necessary.
7. Check Fuel Pump Operation - Connect battery voltage to fuel pump connector terminal No. 1 and ground to terminal No. 4. If fuel pump operates, repair or replace harness connector fuel pump ground circuit. If fuel pump does not operate, replace fuel pump.

1. Check Fuel Injector Operation - Verify injector operation using a stethoscope or screwdriver to hear operating sounds while engine is cranked. If operating sounds are not heard, go to next step. If operating sounds are heard, verify fuel pressure. See «FUEL PRESSURE»(ref-26030-S24269295572001010800000) under FUEL SYSTEM.
2. Check Fuel Injector Power Circuit - Turn ignition off and disconnect each fuel injector connector. Turn ignition on. Measure voltage between each injector connector terminal No. 2 (Yellow wire) and ground. If at least 10 volts are present, go to next step. If less than 9 volts are present, repair harness or connectors as necessary.
3. Check Fuel Injectors - Measure resistance between each fuel injector terminals No. 1 and 2. Resistance between each terminal should be 11-12 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace fuel injector(s). (Scheme 3)
4. Check Resistance Between ECU Connector & Each Injector - Disconnect ECU 22-pin connector. Verify less than 10 ohms resistance between ECU connector terminals No. 1 (Light Green/Red wire), No. 2 (Brown wire), No. 12 (Blue/Red wire), No. 13 (Blue/White wire) and fuel injector terminal No. 1 of each fuel injector connector. If resistance is greater than 10 ohms, repair harness or connectors as necessary. If resistance is less than 10 ohms, inspect ECU connector terminal and repair as necessary. If ECU connector is okay, replace ECU.

Scheme 3

1. Check Fuel Injector Operation - Verify injector operation using a stethoscope or screwdriver to hear operating sounds while engine is cranked. If operating sounds are not heard, go to next step. If operating sounds are heard, verify fuel pressure. See «FUEL PRESSURE»(ref-26030-S24269295572001010800000) under FUEL SYSTEM.
2. Check Fuel Injector Power Circuit - Turn ignition off and disconnect Gray 4-pin fuel injector harness connector. Turn ignition on. Measure voltage between injector harness male connector terminal No. 1 (White/Black wire) and ground. If more than 9 volts are present, go to next step. If more than 9 volts are not present, repair harness or connectors as necessary.
3. Check Fuel Injectors - Measure resistance between Gray 4-pin fuel injector harness connector terminal No. 1 (White/Black wire) and terminals No. 2 (White/Yellow wire), No. 3 (White/Brown wire) and No. 4 (White/Green wire). Verify 10-18 ohms resistance between terminal No. 1 and each specified terminal. If resistance is as specified, go to next step. If resistance is not as specified, go to step 6).
4. Measure Voltage Between ECU Connectors & Fuel Injectors - Connect Gray 4-pin fuel injector harness connector. Turn ignition on. Measure voltage between ECU connector terminals No. 11 (White wire), No. 12 (White/Yellow wire) and No. 25 (White/Green wire) and ground. Measured voltage between each terminal and ground should be more than 8 volts. If more than 8 volts are present, go to next step. If voltage is less than 8 volts, repair harness or connectors as necessary.
5. Check Resistance Between ECU & Ground - Disconnect ECU 26-pin connector. Measure resistance between connector terminal No. 13 (Black/Blue wire) and ground, and between terminal No. 26 (Black/Blue wire) and ground. If resistance is more than 10 ohms, repair harness or connectors between ECU and fuel injectors, as necessary. If resistance is less than 10 ohms, inspect ECU terminal contact. Repair harness or connectors as necessary. If harness and connectors are okay, replace ECU.
6. Check Fuel Injection Engine Harness - Turn ignition off. Remove throttle body from intake manifold. Disconnect each injector 2-pin connector. Disconnect Gray 4-pin fuel injector harness connector. Verify infinity resistance between terminals No. 1 and No. 2 of each injector connector. Verify infinity resistance between terminals No. 2 (White/Yellow wire) and No. 3 (White/Brown wire), No. 2 (White/Yellow wire) and No. 4 (White/Green wire), and No. 3 (White/Brown wire) and 4 (White/Green wire) of 4-pin harness connector. Measure resistance between 4-pin connector and each injector 2-pin connector. See «FUEL INJECTION ENGINE HARNESS RESISTANCE TESTING»(ref-26030-S41059444442001010800000) table. If resistance between harness terminals is not as specified, replace fuel injection engine harness. If resistance between harness connector terminals is as specified, replace malfunctioning fuel injector(s).

FUEL INJECTION ENGINE HARNESS RESISTANCE TESTING (1)

1. Check Fuel Injector Operation - Verify injector operation using a stethoscope or screwdriver to hear operating sounds while engine is cranked. If operating sounds are not heard, go to next step. If operating sounds are heard, verify fuel pressure. See «FUEL PRESSURE»(ref-26030-S24269295572001010800000) under FUEL SYSTEM.
2. Check Fuel Injector Power Circuit - Turn ignition off and disconnect each fuel injector connector. Verify at least 10 volts between each injector terminal No. 2 (Yellow wire) and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
3. Check Fuel Injector Resistance - Disconnect each injector connector. Verify 11-12 ohms resistance between injector terminals No. 1 and 2. If specified resistance is present, go to next step. If specified resistance is not present, replace fuel injector(s).
4. Check Voltage At Each ECU Terminal - Verify at least 10 volts between ground and ECU 26-pin connector terminals No. 11 (Blue/White wire), No. 12 (Light Green wire), No. 13 (Brown wire), and No. 26 (Blue wire). If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
5. Check Harness Connector Between ECU & Ground - Turn ignition off. Disconnect ECU 26-pin connector. Verify zero ohms resistance between connector terminal No. 24 (Black/Yellow wire) and ground, and between terminal No. 25 (Black/Yellow wire) and ground. If specified resistance is not present, repair harness or connectors as necessary. If specified resistance is present, inspect and repair ECU terminal connector. If ECU terminal connector is okay, replace ECU.

1. Check Fuel Injector Operation - Verify injector operation using a stethoscope or screwdriver to hear operating sounds while engine is cranked. If operating sounds are not heard, go to next step. If operating sounds are heard, verify fuel pressure. See «FUEL PRESSURE»(ref-26030-S24269295572001010800000) under FUEL SYSTEM.
2. Check Fuel Injector Resistance - Disconnect each injector connector. Verify less than 2 ohms resistance between injector terminals No. 1 and 2. If specified resistance is present, go to next step. If specified resistance is not present, replace fuel injector(s).
3. Check Injector Harness Resistance - Verify more than one megohm of resistance between each terminal of injector side of connector and ground. If resistance is not as specified, replace injector(s). If resistance is as specified, replace ECU.

1. Check Fuel Injector Operation - Verify injector operation using a stethoscope or screwdriver to hear operating sounds while engine is cranked. If operating sounds are not heard, go to next step. If operating sounds are heard, verify fuel pressure. See «FUEL PRESSURE»(ref-26030-S24269295572001010800000) under FUEL SYSTEM.
2. Check Fuel Injector Power Circuit - Turn ignition off and disconnect each fuel injector connector. Verify at least 10 volts between each injector connector terminal and ground. If at least 10 volts are present, go to next step. If at least 10 volts are not present, repair harness or connectors as necessary.
3. Check Fuel Injectors - Measure resistance between connector terminals of each fuel injector. If resistance is 11-12 ohms, go to next step. If resistance is not 11-12 ohms, replace injector(s).
4. Measure Voltage Between ECU Connectors & Fuel Injectors - Connect fuel injector connectors and turn ignition on. Measure voltage between ECU connector terminals and ground. Refer to the «FUEL INJECTION & ECU HARNESS VOLTAGE TESTING»(ref-26030-S12029584862001010800000) table. If at least 5 volts are present, go to next step. If at least 5 volts are not present, repair or replace harness or connectors as necessary.
5. Check ECU Ground Circuit Resistance - Disconnect ECU 26-pin connector. Measure resistance between connector terminal No. 24 (Blue/Black wire) and ground and between terminal No. 25 (Black/Yellow wire) and ground. If resistance is more than zero ohms, repair harness or connectors between ECU and ground. Inspect ECU connector terminal. If ECU connector terminal is okay, replace ECU.

FUEL INJECTION & ECU HARNESS VOLTAGE TESTING

SUMMARY

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to appropriate SELF DIAGNOSTICS article. If no hard codes are found in self-diagnostics, go to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.