Home ReviewsRefund
Home/Subaru/Impreza/Subaru Impreza GD/GC/GG рестайлинг (2002-2005)/Repair manual/Testing & Diagnostics/Engine Controls - Basic Diagnostic Procedures: Other
Contents Section: Testing & Diagnostics All sections

Engine Controls - Basic Diagnostic Procedures: Other Subaru Impreza GD/GC/GG рестайлинг

Testing & Diagnostics 20 illustrations ~12705 words

Cylinder Compression Pressure

Ensure battery is fully charged and starter motor is in good operating condition. Warm engine to normal operating temperature and turn ignition off. Release fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE . Clean spark plug recesses with compressed air and remove all spark plugs. Install compression gauge. Hold throttle in Wide Open Throttle (WOT) position. Using a remote starter switch, rotate engine 2 revolutions and record maximum value shown on compression gauge when pointer is steady. Continue test for remaining cylinders. See COMPRESSION SPECIFICATIONS table. Install and tighten spark plugs to 15.5 ft. lbs. (21 N.m).

ApplicationSpecification
Normal Compression Pressure
2.0L142-171 psi (10.0-12.0 kg/cm 2 )
2.5L185 psi (13.0 kg/cm 2 )
3.0L185-213 psi (13.0-15.0 kg/cm 2 )
Minimum Compression Pressure
2.0L121 psi (8.5 kg/cm 2 )
2.5L156 psi (11.0 kg/cm 2 )
3.0L164 psi (11.5 kg/cm 2 )
Maximum Variation Between Cylinders
All Models7 psi (0.5 kg/cm 2 )

COMPRESSION SPECIFICATIONS

Checking Engine Vacuum

Warm engine to normal operating temperature. Disconnect brake vacuum hose at manifold and install vacuum gauge to hose fitting on manifold. With engine at idle, read vacuum gauge. Normal engine vacuum reading should be less than 17.72 in. Hg with engine at idle and A/C off. While monitoring engine vacuum reading, quickly open and close the throttle several times and then allow engine to idle. If engine vacuum is within specification, test is complete. If engine vacuum is not within specification, check for vacuum leaks and repair as necessary. If no vacuum leaks are found, check for engine mechanical problem. See MANIFOLD VACUUM READING DIAGNOSIS table.

Vacuum Gauge IndicationPossible Cause
Needle Steady, But Lower Than Normal ReadingIntake Manifold Gasket Leak Or Damaged/Disconnected Vacuum Hose
Needle Temporarily Stops Or Is Steady Above Normal Reading When Engine Speed Is Slowly Reduced From High SpeedExhaust Backpressure Too High Or Clogged Exhaust System
Needle Intermittently Drops To Lower Than Normal ReadingLeak Around Cylinder
Needle Vibrates Rapidly At A Certain Speed As Engine Speed Is Gradually Increased & Then Vibration Increases With Engine SpeedWeak Or Broken Valve Springs
Needle Vibrates In Narrow Range Above & Below Normal ReadingDefective Ignition System Or Throttle Idle Adjustment

MANIFOLD VACUUM READING DIAGNOSIS

STARTER CIRCUIT

Note. Before performing following tests, ensure adequate fuel in fuel tank and battery open circuit voltage is more than 12 volts.

Scheme 2

Scheme 2: Baja, Legacy & Outback 2.5L
Scheme 2: Baja, Legacy & Outback 2.5L

Scheme 3

Scheme 3
Scheme 3

Scheme 4

Scheme 4
Scheme 4

Scheme 5

Scheme 5
Scheme 5
  1. Using Customer Complaint Check List, attempt to start engine. see scheme 1 If starter operates when ignition switch is turned but engine does not start, go to next step. If starter does not operate when ignition switch is turned, go to step 3.
  2. Check for Diagnostic Trouble Codes (DTCs) stored in memory. If DTCs are present, repair cause of problem and retest system. See appropriate SELF-DIAGNOSTICS article. If DTCs are not present, check Engine Control Module (ECM) power feed and ground circuits. See «ENGINE CONTROL MODULE POWER SUPPLY & GROUND CIRCUITS»(ref-157416-S07258394282003081200000).
  3. Turn ignition off. Disconnect starter single-pin electrical harness connector. Using a DVOM, measure voltage of White/Green wire (White/Blue wire on models with anti-theft system) between starter single-pin electrical harness connector and good engine ground point while holding ignition switch in ST position. Ensure gear selector is in Park or Neutral on automatic transaxles or clutch pedal is depressed on manual transaxles while activating starter. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, go to step 5.
  4. Turn ignition off. Disconnect ground cable from starter. Using a DVOM, measure resistance of ground cable between ground cable terminal and engine ground point. If resistance is less than 5 ohms, check starter. See appropriate STARTERS article in ENGINE. If resistance is not less than 5 ohms, repair open in ground circuit. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off. Access ignition switch and disconnect ignition switch Blue 4-pin electrical harness connector. Using a DVOM, measure voltage on White wire between ignition switch Blue 4-pin electrical harness connector terminal No. 1 and good body ground point. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, check slow blow fuses No. 1 (100-amp) and No. 4 (50-amp) located in main fuse box at left side of engine compartment at shock tower. If fuses are blown, replace fuses and locate and repair open in power feed circuit between ignition switch and battery. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Check ignition switch. See IGNITION SWITCH under COMPONENT TESTS in appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step.
  7. If vehicle is equipped with manual transaxle, go to step 9. On vehicles with automatic transaxle, turn ignition off and reconnect ignition switch Blue 4-pin electrical harness connector. Separate Black 12-pin transaxle electrical harness connector on top of transaxle assembly. Using a DVOM, measure voltage of White/Black wire (White/Green wire on models with anti-theft system) between harness side of 12-pin transaxle electrical harness connector terminal No. 12 and good engine ground point while turning ignition to ST position. (Scheme 2) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, check anti-theft system (if equipped). See appropriate ANTI-THEFT article in ACCESSORIES & EQUIPMENT. If anti-theft system is okay, repair White/Black wire (White/Green wire on models with anti-theft system) between inhibitor switch and ignition switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  8. With ignition off, place transaxle selector lever in Park or Neutral. Using a DVOM, measure resistance on transaxle side of 12-pin transaxle electrical harness connector between terminals No. 11 (Black/White wire) and No. 12 (Black/Yellow wire). (Scheme 3) If resistance is less than one ohm, repair open or short to ground in White/Green wire (White/Blue wire on models with anti-theft system) between inhibitor switch and starter. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If resistance is not less than one ohm, replace inhibitor switch.
  9. On manual transaxle vehicles, turn ignition off. Reconnect ignition switch 4-pin electrical harness connector. Remove Blue starter interlock relay from fuse and relay block located on bulkhead under left side of instrument panel. Using a DVOM, measure voltage on White/Black wire (White/Green wire on models with anti-theft system) between starter interlock relay cavities No. 1 and 3 and good chassis ground point while turning ignition switch to ST position. (Scheme 4) If voltage is more than 10 volts at both test points, go to next step. If voltage is not more than 10 volts at both test points, repair open or short to ground in power feed circuit (White/Green wires on models with anti-theft or White/Black wires on models without anti-theft) between starter interlock relay and ignition switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Check anti-theft system, if equipped. See appropriate ANTI-THEFT SYSTEMS article in ACCESSORIES & EQUIPMENT.
  10. Turn ignition off and remove starter interlock relay. Using jumper wires, apply battery voltage to starter interlock relay terminals No. 2 and 3. Measure resistance across interlock relay terminals No. 1 and 4. (Scheme 5) If resistance is less than one ohm, go to next step. If resistance is greater than one ohm, replace starter interlock relay.
  11. Turn ignition off. Locate and disconnect clutch switch 2-pin electrical harness connector. Measure resistance between clutch switch 2-pin electrical harness connector terminal No. 1 (Black wire) and good chassis ground point. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair clutch switch ground circuit. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  12. With ignition off and clutch switch still disconnected, connect DVOM across terminals of clutch switch. With clutch pedal depressed, resistance should be less than one ohm. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, replace clutch switch.
  13. Turn ignition off and reconnect clutch switch 2-pin electrical harness connector. Remove Blue starter interlock relay from fuse and relay block located on bulkhead under left side of instrument panel. Using a DVOM, measure resistance between starter interlock relay cavity No. 2 (Green/Yellow wire) and good chassis ground point while depressing clutch. (Scheme 4) If resistance is less than one ohm, repair short to ground in White/Green wire (White/Blue wire on models with anti-theft system) between starter interlock relay and starter motor. If resistance is not less than one ohm, repair open circuit in Green/Yellow wire between starter interlock relay and clutch switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

Scheme 6

Scheme 6: Forester
Scheme 6: Forester

Scheme 7

Scheme 7
Scheme 7
  1. Using Customer Complaint Check List, attempt to start engine. see scheme 1 If starter operates when ignition switch is turned but engine does not start, go to next step. If starter does not operate when ignition switch is turned, go to step 3.
  2. Check for Diagnostic Trouble Codes (DTCs) stored in memory. If DTCs are present, repair cause of problem and retest system. See appropriate SELF-DIAGNOSTICS article. If DTCs are not present, check Engine Control Module (ECM) power feed and ground circuits. See «ENGINE CONTROL MODULE POWER SUPPLY & GROUND CIRCUITS»(ref-157416-S07258394282003081200000).
  3. Turn ignition off. Disconnect starter single-pin electrical harness connector. Using a DVOM, measure voltage of Yellow/Blue wire between starter single-pin electrical harness connector and good engine ground point while holding ignition switch in ST position. Ensure gear selector is in Park or Neutral on automatic transaxles or clutch pedal is depressed on manual transaxles while activating starter. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, go to step 5.
  4. Turn ignition off. Disconnect ground cable from starter. Using a DVOM, measure resistance of ground cable between ground cable terminal and engine ground point. If resistance is less than 5 ohms, check starter. See appropriate STARTERS article in ENGINE. If resistance is not less than 5 ohms, repair open in ground circuit. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off. Access ignition switch and disconnect ignition switch Black 4-pin electrical harness connector. Using a DVOM, measure voltage on White wire between ignition switch Black 4-pin electrical harness connector terminal No. 1 and good body ground point. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, check slow blow fuses No. 1 (100-amp) and No. 4 (50-amp) located in main fuse box at left side of engine compartment at shock tower. If fuses are blown, replace fuses and locate and repair open in power feed circuit between ignition switch and battery. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Check ignition switch. See IGNITION SWITCH under COMPONENT TESTS in appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step.
  7. If vehicle is equipped with manual transaxle, go to step 9. On vehicles with automatic transaxle, turn ignition off and reconnect ignition switch Black 4-pin electrical harness connector. Separate 12-pin transaxle electrical harness connector on top of transaxle assembly. Using a DVOM, measure voltage of White/Red wire between harness side of 12-pin transaxle electrical harness connector terminal No. 12 and good engine ground point while turning ignition to ST position. (Scheme 2) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, check anti-theft system (if equipped). See appropriate ANTI-THEFT article in ACCESSORIES & EQUIPMENT. If anti-theft system is okay, repair White/Red wire between 12-pin transaxle electrical harness connector and ignition switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  8. With ignition off, place transaxle selector lever in Park or Neutral. Using a DVOM, measure resistance on transaxle side of 12-pin transaxle electrical harness connector between terminals No. 11 (Black/White wire) and No. 12 (Black/Yellow wire). (Scheme 3) If resistance is less than one ohm, repair open or short to ground in Yellow/Blue wire between inhibitor switch and starter. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If resistance is not less than one ohm, replace inhibitor switch.
  9. On manual transaxle vehicles, turn ignition off. Reconnect ignition switch Black 4-pin electrical harness connector. Remove starter interlock relay from Black fuse and relay block located on bulkhead under left side of instrument panel. Using a DVOM, measure voltage between starter interlock relay cavities No. 26 and 28 and good chassis ground point while turning ignition switch to ST position. (Scheme 6) If voltage is more than 10 volts at both test points, go to next step. If voltage is not more than 10 volts at both test points, repair open or short to ground in power feed circuit (White/Red wires) between starter interlock relay and ignition switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Check anti-theft system, if equipped. See appropriate ANTI-THEFT SYSTEMS article in ACCESSORIES & EQUIPMENT.
  10. Using jumper wires, apply battery voltage to starter interlock relay terminals No. 24 and 26. Measure resistance across interlock relay terminals No. 27 and 28. (Scheme 7) If resistance is less than one ohm, go to next step. If resistance is greater than one ohm, replace starter interlock relay.
  11. Turn ignition off. Locate and disconnect clutch switch 2-pin electrical harness connector. Measure resistance between clutch switch 2-pin electrical harness connector terminal No. 1 (Black wire) and good chassis ground point. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair clutch switch ground circuit. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  12. With ignition off and clutch switch still disconnected, connect DVOM across terminals of clutch switch. With clutch pedal depressed, resistance should be less than one ohm. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, replace clutch switch.
  13. Turn ignition off and reconnect clutch switch 2-pin electrical harness connector. Remove starter interlock relay from Black fuse and relay block located on bulkhead under left side of instrument panel. Using a DVOM, measure resistance between starter interlock relay cavity No. 24 and good chassis ground point while depressing clutch. (Scheme 6) If resistance is less than one ohm, repair short to ground in Yellow/Blue wire between starter interlock relay and starter motor. If resistance is not less than one ohm, repair open circuit in Green/Yellow wire between starter interlock relay and clutch switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

Impreza & Outback Sport

  1. Using Customer Complaint Check List, attempt to start engine. see scheme 1 If starter operates when ignition switch is turned but engine does not start, go to next step. If starter does not operate when ignition switch is turned, go to step 3.
  2. Check for Diagnostic Trouble Codes (DTCs) stored in memory. If DTCs are present, repair cause of problem and retest system. See appropriate SELF-DIAGNOSTICS article. If DTCs are not present, check Engine Control Module (ECM) power feed and ground circuits. See «ENGINE CONTROL MODULE POWER SUPPLY & GROUND CIRCUITS»(ref-157416-S07258394282003081200000).
  3. Turn ignition off. Disconnect starter single-pin electrical harness connector. Using a DVOM, measure voltage of Yellow wire between starter single-pin electrical harness connector and good engine ground point while holding ignition switch in ST position. Ensure gear selector is in Park or Neutral on automatic transaxles or clutch pedal is depressed on manual transaxles while activating starter. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, go to step 5.
  4. Turn ignition off. Disconnect ground cable from starter. Using a DVOM, measure resistance of ground cable between ground cable terminal and engine ground point. If resistance is less than 5 ohms, check starter. See appropriate STARTERS article in ENGINE. If resistance is not less than 5 ohms, repair open in ground circuit. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off. Access ignition switch and disconnect ignition switch Blue 4-pin electrical harness connector. Using a DVOM, measure voltage on White wire between ignition switch Blue 4-pin electrical harness connector terminal No. 1 and good body ground point. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, check slow blow fuses No. 1 (80-amp) and No. 4 (50-amp) located in main fuse box at left side of engine compartment at shock tower. If fuses are blown, replace fuses and locate and repair open in power feed circuit between ignition switch and battery. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Check ignition switch. See IGNITION SWITCH under COMPONENT TESTS in appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step.
  7. If vehicle is equipped with manual transaxle, go to step 9. On vehicles with automatic transaxle, turn ignition off and reconnect ignition switch Blue 4-pin electrical harness connector. Separate 12-pin transaxle electrical harness connector on top of transaxle assembly. Using a DVOM, measure voltage of White/Red wire between harness side of 12-pin transaxle electrical harness connector terminal No. 12 and good engine ground point while turning ignition to ST position. (Scheme 2) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, check anti-theft system (if equipped). See appropriate ANTI-THEFT article in ACCESSORIES & EQUIPMENT. If anti-theft system is okay, repair White/Red wire between inhibitor switch and ignition switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  8. With ignition off, place transaxle selector lever in Park or Neutral. Using a DVOM, measure resistance on transaxle side of 12-pin transaxle electrical harness connector between terminals No. 11 (Black/White wire) and No. 12 (Black/Yellow wire). (Scheme 3) If resistance is less than one ohm, repair open or short to ground in Yellow/Blue wire between ignition switch and starter. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If resistance is not less than one ohm, replace inhibitor switch.
  9. On manual transaxle vehicles, turn ignition off. Reconnect ignition switch 4-pin electrical harness connector. Remove starter interlock relay from Black fuse and relay block located on bulkhead under left side of instrument panel. Using a DVOM, measure voltage between starter interlock relay cavities No. 24 and 27 and good chassis ground point while turning ignition switch to ST position. (Scheme 6) If voltage is more than 10 volts at both test points, go to next step. If voltage is not more than 10 volts at both test points, repair open or short to ground in power feed circuit (White/Red wires) between starter interlock relay and ignition switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Check anti-theft system, if equipped. See appropriate ANTI-THEFT SYSTEMS article in ACCESSORIES & EQUIPMENT.
  10. Using jumper wires, apply battery voltage to starter interlock relay terminals No. 24 and 26. Measure resistance across interlock relay terminals No. 27 and 28. (Scheme 7) If resistance is less than one ohm, go to next step. If resistance is greater than one ohm, replace starter interlock relay.
  11. Turn ignition off. Locate and disconnect clutch switch 2-pin electrical harness connector. Measure resistance between clutch switch 2-pin electrical harness connector terminal No. 1 (Black wire) and good chassis ground point. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair clutch switch ground circuit. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  12. With ignition off and clutch switch still disconnected, connect DVOM across terminals of clutch switch. With clutch pedal depressed, resistance should be less than one ohm. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, replace clutch switch.
  13. Turn ignition off and reconnect clutch switch 2-pin electrical harness connector. Remove starter interlock relay from Black fuse and relay block located on bulkhead under left side of instrument panel. Using a DVOM, measure resistance between starter interlock relay cavity No. 26 and good chassis ground point while depressing clutch. (Scheme 6) If resistance is less than one ohm, repair short to ground in Yellow wire between starter interlock relay and starter motor. If resistance is not less than one ohm, repair open circuit in Green/Yellow wire between starter interlock relay and clutch switch. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

Scheme 8

Scheme 8: Outback 3.0L
Scheme 8: Outback 3.0L
  1. Using Customer Complaint Check List, attempt to start engine. see scheme 1 If starter operates when ignition switch is turned but engine does not start, go to next step. If starter does not operate when ignition switch is turned, go to step 3.
  2. Check for Diagnostic Trouble Codes (DTCs) stored in memory. If DTCs are present, repair cause of problem and retest system. See appropriate SELF-DIAGNOSTICS article. If DTCs are not present, check Engine Control Module (ECM) power feed and ground circuits. See «ENGINE CONTROL MODULE POWER SUPPLY & GROUND CIRCUITS»(ref-157416-S07258394282003081200000).
  3. Turn ignition off. Disconnect starter single-pin electrical harness connector. Using a DVOM, measure voltage of White/Green wire (White/Blue wire on models with anti-theft system) between starter single-pin electrical harness connector and good engine ground point while holding ignition switch in ST position. Ensure gear selector is in Park or Neutral while activating starter. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, go to step 5.
  4. Turn ignition off. Disconnect ground cable from starter. Using a DVOM, measure resistance of ground cable between ground cable terminal and engine ground point. If resistance is less than 5 ohms, check starter. See appropriate STARTERS article in ENGINE. If resistance is not less than 5 ohms, repair open in ground circuit. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off. Access ignition switch and disconnect ignition switch Blue 4-pin electrical harness connector. Using a DVOM, measure voltage on White wire between ignition switch Blue 4-pin electrical harness connector terminal No. 1 and good body ground point. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, check slow blow fuses No. 1 (100-amp) and No. 4 (50-amp) located in main fuse box at left side of engine compartment at shock tower. If fuses are blown, replace fuses and locate and repair open in power feed circuit between ignition switch and battery. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Reconnect ignition switch Blue 4-pin electrical harness connector. Using a DVOM, backprobe between ignition switch Blue 4-pin electrical harness connector terminal No. 3 (White/Black wire) and good chassis ground point with ignition in ST position. If voltage is greater than 10 volts, go to step 8. If voltage is not greater than 10 volts, go to next step.
  7. Check ignition switch Blue 4-pin electrical harness connector for poor contact. If poor contact is present in connector, repair as necessary. If contact is okay, replace ignition switch. See REMOVAL & INSTALLATION in appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.
  8. Turn ignition off and separate Black 12-pin transaxle electrical harness connector on top of transaxle assembly. Place transaxle selector lever in Park or Neutral. Using a DVOM, measure resistance on transaxle side of 12-pin transaxle electrical harness connector between terminals No. 11 (Black/White wire) and No. 12 (Black/Yellow wire). (Scheme 3) If resistance is not less than one ohm, go to next step. If resistance is less than one ohm, repair open in appropriate wire between ignition switch and starter. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  9. With ignition off and Black 12-pin transaxle electrical harness connector on top of transaxle assembly disconnected, disconnect 12-pin electrical harness connector from inhibitor switch. Using a DVOM, measure resistance of Black/White wire between transaxle side of 12-pin transaxle electrical harness connector terminal No. 11 and harness side of 12-pin inhibitor switch electrical harness connector terminal No. 7. (Scheme 3)and (Scheme 8). If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open in Black/White wire between transaxle harness connector and inhibitor switch connector. See appropriate STARTING/CHARGING wiring diagram in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  10. Check 12-pin inhibitor switch electrical harness connector for poor contact. If poor contact is present in connector, repair as necessary. If contact is okay, replace inhibitor switch. See REMOVAL & INSTALLATION in appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.

Scheme 9

Scheme 9: Baja, Legacy & Outback 2.5L
Scheme 9: Baja, Legacy & Outback 2.5L

Scheme 10

Scheme 10
Scheme 10
  1. Turn ignition off. Remove main relay. Main relay is located under right side of dash. Connect battery voltage to relay terminals No. 1 and 2. Using a DVOM, measure resistance between terminals No. 3 and 5 and between terminals No. 4 and 6. (Scheme 9) If resistance is less than 10 ohms at both test points, go to next step. If resistance is not less than 10 ohms at both test points, replace main relay.
  2. Turn ignition off. Disconnect connectors from Engine Control Module (ECM). Using a DVOM, measure resistance between specified terminals on harness side of specified ECM electrical harness connector and good chassis ground point. See «ECM GROUND CIRCUIT RESISTANCE (BAJA, LEGACY & OUTBACK 2.5L)»(ref-157416-S30792099172003102400000) table. (Scheme 10) If resistance is as specified, go to next step. If resistance is not as specified, repair open circuit in suspect ground circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. ECM GROUND CIRCUIT RESISTANCE (BAJA, LEGACY & OUTBACK 2.5L) ECM Connector & Terminal No. (Wire Color) Specification 35-Pin B134 7 (Black/White) Less Than 5 Ohms 35 (Black/Pink) Less Than 5 Ohms 28-Pin B135 21 (Black/Blue) Less Than 5 Ohms 26-Pin B136 5 (Black/Blue) Less Than 5 Ohms 16 (Black/Blue) Less Than 5 Ohms 19 (Black/Blue) - M/T Only Less Than 5 Ohms 20-Pin B137 14 (Black/Blue) Less Than 5 Ohms
  3. With ignition off and all ECM connectors still disconnected, measure voltage between harness side of 28-pin ECM electrical harness connector B135 terminal No. 9 (Black/Red wire) and good chassis ground point. (Scheme 10) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair power feed circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. With all ECM connectors still disconnected, turn ignition on. Using a DVOM, measure voltage between harness side of 26-pin ECM electrical harness connector B136 terminal No. 21 (White/Black wire) and good chassis ground point. (Scheme 10) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open or short to ground in power supply circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off and leave all ECM connectors disconnected. Using a DVOM, measure resistance between harness side of 26-pin ECM electrical harness connector B136 terminal No. 12 (Light Green wire) and good chassis ground point. (Scheme 10) If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short to ground in harness between ECM and main relay, and check ECM for damage. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Turn ignition off and reconnect all ECM connectors. Turn ignition on. Backprobing, measure voltage between harness side of 26-pin ECM electrical harness connector B136 terminal No. 12 (Light Green wire) and good chassis ground point. (Scheme 10) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, replace ECM.
  7. Turn ignition off. Disconnect main relay 6-pin electrical harness connector. Turn ignition on. Using a DVOM, measure voltage between main relay 6-pin electrical harness connector terminal No. 2 (Light Green wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open circuit in Light Green wire between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  8. With main relay 6-pin electrical harness connector disconnected, turn ignition off. Using a DVOM, measure resistance between main relay 6-pin electrical harness connector terminal No. 1 (Black wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in ground circuit (Black wire) between main relay and chassis ground point located at rear of engine compartment. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  9. With main relay 6-pin electrical harness connector disconnected, measure voltage of Black/Red wires between main relay 6-pin electrical harness connector terminals No. 5 and 6 and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open or short to ground in power feed circuits (Black/Red wires) between main relay and main fuse block located in engine compartment. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  10. Turn ignition off and reconnect main relay 6-pin electrical harness connector. Turn ignition on. Backprobing, measure voltage between 28-pin ECM electrical harness connector B135 terminals No. 1 and 2 (Yellow/Blue wires) and good chassis ground point. (Scheme 10) If voltage is greater than 10 volts, check ignition control system. See «IGNITION SYSTEMS»(ref-157416-S12337035572003081200000). If voltage is not greater than 10 volts, repair open or short to ground in Yellow/Blue wires between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

Scheme 11

Scheme 11: Forester, Impreza 2.5L & Outback Sport
Scheme 11: Forester, Impreza 2.5L & Outback Sport
  1. Turn ignition off. Remove main relay. Main relay is located under right side of dash. Connect battery voltage to relay terminals No. 1 and 2. Using a DVOM, measure resistance between terminals No. 3 and 5 and between terminals No. 4 and 6. (Scheme 9) If resistance is less than 10 ohms at both test points, go to next step. If resistance is not less than 10 ohms at both test points, replace main relay.
  2. Turn ignition off. Disconnect connectors from Engine Control Module (ECM). Using a DVOM, measure resistance between specified terminals on harness side of specified ECM electrical harness connector and good chassis ground point. See «ECM GROUND CIRCUIT RESISTANCE (FORESTER, IMPREZA 2.5L & OUTBACK SPORT)»(ref-157416-S19146463312003102400000) table. (Scheme 11) If resistance is as specified, go to next step. If resistance is not as specified, repair open circuit in suspect ground circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. ECM GROUND CIRCUIT RESISTANCE (FORESTER, IMPREZA 2.5L & OUTBACK SPORT) ECM Connector & Terminal No. (Wire Color) Specification 28-Pin B134 21 (Black/Red) Less Than 5 Ohms 20-Pin B135 14 (Black/Red) Less Than 5 Ohms 26-Pin B136 5 (Black/Yellow) Less Than 5 Ohms 16 (Black/Yellow) Less Than 5 Ohms 19 (Black/Red) - M/T Only Less Than 5 Ohms 26 (Black) Less Than 5 Ohms 35-Pin B137 - Forester 7 (Black/White) Less Than 5 Ohms 35 (Black/Orange) Less Than 5 Ohms 35-Pin B137 - Impreza & Outback Sport 7 (Black/White) Less Than 5 Ohms 35 (Black/Green) Less Than 5 Ohms
  3. With ignition off and all ECM connectors still disconnected, measure voltage between harness side of 28-pin ECM electrical harness connector B134 terminal No. 9 (Black/Red wire) and 26-pin ECM electrical harness connector B136 terminal No. 10 (Green/Red wire) and good chassis ground point. (Scheme 11) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair power feed circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. Turn ignition off and leave all ECM connectors disconnected. Using a DVOM, measure resistance between harness side of 26-pin ECM electrical harness connector B136 terminal No. 12 (Light Green/White wire) and good chassis ground point. (Scheme 11) If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short to ground in harness between ECM and main relay, and check ECM for damage. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off and reconnect all ECM connectors. Turn ignition on. Backprobing, measure voltage between harness side of 26-pin ECM electrical harness connector B136 terminal No. 12 (Light Green/White wire) and good chassis ground point. (Scheme 11) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, replace ECM.
  6. Turn ignition off. Disconnect main relay 6-pin electrical harness connector. Turn ignition on. Using a DVOM, measure voltage between main relay 6-pin electrical harness connector terminal No. 2 (Light Green/White wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open circuit in Light Green/White wire between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  7. With main relay 6-pin electrical harness connector disconnected, turn ignition off. Using a DVOM, measure resistance between main relay 6-pin electrical harness connector terminal No. 1 (Black wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in ground circuit (Black wire) between main relay and chassis ground point located at right kick panel on Forester and right side of instrument panel on Impreza 2.5L and Outback Sport. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  8. With main relay 6-pin electrical harness connector disconnected, measure voltage of Black/Red wires between main relay 6-pin electrical harness connector terminals No. 5 and 6 and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open or short to ground in power feed circuits (Black/Red wires) between main relay and main fuse block located in engine compartment. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  9. Turn ignition off and reconnect main relay 6-pin electrical harness connector. Turn ignition on. Backprobing, measure voltage on Yellow/Blue wires between 28-pin ECM electrical harness connector B134 terminals No. 1 and 2 and good chassis ground point. On Forester only, also backprobe between 26-pin ECM electrical harness connector B136 terminal No. 23 (Yellow/Red wire) and good chassis ground point. (Scheme 11) If voltage is greater than 10 volts, check ignition control system. See «IGNITION SYSTEMS»(ref-157416-S12337035572003081200000). If voltage is not greater than 10 volts, repair open or short to ground in suspect wires between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

Scheme 12

Scheme 12: Impreza WRX 2.0L
Scheme 12: Impreza WRX 2.0L
  1. Turn ignition off. Remove main relay. Main relay is located under right side of dash. Connect battery voltage to relay terminals No. 1 and 2. Using a DVOM, measure resistance between terminals No. 3 and 5 and between terminals No. 4 and 6. (Scheme 9) If resistance is less than 10 ohms at both test points, go to next step. If resistance is not less than 10 ohms at both test points, replace main relay.
  2. Turn ignition off. Disconnect connectors from Engine Control Module (ECM). Using a DVOM, measure resistance between specified terminals on harness side of specified ECM electrical harness connector and good chassis ground point. See «ECM GROUND CIRCUIT RESISTANCE (IMPREZA WRX 2.0L)»(ref-157416-S30720129502003102900000) table. (Scheme 12) If resistance is as specified, go to next step. If resistance is not as specified, repair open circuit in suspect ground circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. ECM GROUND CIRCUIT RESISTANCE (IMPREZA WRX 2.0L) ECM Connector & Terminal No. (Wire Color) Specification 22-Pin B134 7 (Black/Red) Less Than 5 Ohms 15 (Black/Red) Less Than 5 Ohms 22 (Black/Red) Less Than 5 Ohms 24-Pin B136 8 (Black/Yellow) Less Than 5 Ohms 17 (Black/White) Less Than 5 Ohms 18 (Black) Less Than 5 Ohms 31-Pin B137 8 (Black/Blue) Less Than 5 Ohms 9 (Black/Blue) Less Than 5 Ohms 17-Pin B84 1 (Black/Red) - M/T Only Less Than 5 Ohms
  3. With ignition off and all ECM connectors still disconnected, measure voltage between harness side of 22-pin ECM electrical harness connector B134 terminal No. 5 (Green/Red wire) and 31-pin ECM electrical harness connector B137 terminal No. 10 (Black/Red wire) and good chassis ground point. (Scheme 12) If voltage is greater than 10 volts at both test points, go to next step. If voltage is not greater than 10 volts at both test points, repair power feed circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. Turn ignition off and leave all ECM connectors disconnected. Using a DVOM, measure resistance between harness side of 22-pin ECM electrical harness connector B134 terminal No. 6 (Light Green/White wire) and good chassis ground point. (Scheme 12) If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short to ground in harness between ECM and main relay, and check ECM for damage. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off and reconnect all ECM connectors. Turn ignition on. Backprobing, measure voltage between harness side of 22-pin ECM electrical harness connector B134 terminal No. 6 (Light Green/White wire) and good chassis ground point. (Scheme 12) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, replace ECM.
  6. Turn ignition off. Disconnect main relay 6-pin electrical harness connector. Turn ignition on. Using a DVOM, measure voltage between main relay 6-pin electrical harness connector terminal No. 2 (Light Green/White wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open circuit in Light Green/White wire between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  7. With main relay 6-pin electrical harness connector disconnected, turn ignition off. Using a DVOM, measure resistance between main relay 6-pin electrical harness connector terminal No. 1 (Black wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in ground circuit (Black wire) between main relay and chassis ground located at right side of instrument panel. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  8. With main relay 6-pin electrical harness connector disconnected, measure voltage between main relay 6-pin electrical harness connector terminals No. 5 (Blue/Red wire) and No. 6 (Black/Red wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open or short to ground in suspect power feed circuit between main relay and main fuse block located in engine compartment. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  9. Turn ignition off and reconnect main relay 6-pin electrical harness connector. Turn ignition on. Backprobing, measure voltage on Yellow/Blue wires between 31-pin ECM electrical harness connector B137 terminals No. 2 and 3 and good chassis ground point. (Scheme 12) If voltage is greater than 10 volts, check ignition control system. See «IGNITION SYSTEMS»(ref-157416-S12337035572003081200000). If voltage is not greater than 10 volts, repair open or short to ground in suspect wires between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

Scheme 13

Scheme 13: Outback 3.0L
Scheme 13: Outback 3.0L
  1. Turn ignition off. Remove main relay. Main relay is located under right side of dash. Connect battery voltage to relay terminals No. 1 and 2. Using a DVOM, measure resistance between terminals No. 3 and 5 and between terminals No. 4 and 6. (Scheme 9) If resistance is less than 10 ohms at both test points, go to next step. If resistance is not less than 10 ohms at both test points, replace main relay.
  2. Turn ignition off. Disconnect connectors from Engine Control Module (ECM). Using a DVOM, measure resistance between specified terminals on harness side of specified ECM electrical harness connector and good chassis ground point. See «ECM GROUND CIRCUIT RESISTANCE (OUTBACK 3.0L)»(ref-157416-S09290534832003102900000) table. (Scheme 13) If resistance is as specified, go to next step. If resistance is not as specified, repair open circuit in suspect ground circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. ECM GROUND CIRCUIT RESISTANCE (OUTBACK 3.0L) ECM Connector & Terminal No. (Wire Color) Specification 22-Pin B134 22 (Black/White) Less Than 5 Ohms 24-Pin B136 8 (Black/Pink) Less Than 5 Ohms 17 (Black/White) Less Than 5 Ohms 18 (Black) Less Than 5 Ohms 31-Pin B137 8 (Black/White) Less Than 5 Ohms 9 (Black/White) Less Than 5 Ohms 21 (Black/Yellow) Less Than 5 Ohms 31 (Black/Yellow) Less Than 5 Ohms
  3. With ignition off and all ECM connectors still disconnected, measure voltage between harness side of 22-pin ECM electrical harness connector B134 terminal No. 8 (White/Black wire) and 31-pin ECM electrical harness connector B137 terminal No. 10 (Black/Red wire) and good chassis ground point. (Scheme 13) If voltage is greater than 10 volts at both test points, go to next step. If voltage is not greater than 10 volts at both test points, repair power feed circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. Turn ignition off and leave all ECM connectors disconnected. Using a DVOM, measure resistance between harness side of 22-pin ECM electrical harness connector B134 terminal No. 6 (Light Green wire) and good chassis ground point. (Scheme 13) If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short to ground in harness between ECM and main relay, and check ECM for damage. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off and reconnect all ECM connectors. Turn ignition on. Backprobing, measure voltage between harness side of 22-pin ECM electrical harness connector B134 terminal No. 6 (Light Green wire) and good chassis ground point. (Scheme 13) If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, replace ECM.
  6. Turn ignition off. Disconnect main relay 6-pin electrical harness connector. Turn ignition on. Using a DVOM, measure voltage between main relay 6-pin electrical harness connector terminal No. 2 (Light Green wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open circuit in Light Green wire between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  7. With main relay 6-pin electrical harness connector disconnected, turn ignition off. Using a DVOM, measure resistance between main relay 6-pin electrical harness connector terminal No. 1 (Black wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in ground circuit (Black wire) between main relay and chassis ground point located at rear of engine compartment. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  8. With main relay 6-pin electrical harness connector disconnected, measure voltage between main relay 6-pin electrical harness connector terminals No. 5 (Black/Red wire) and No. 6 (Black/White wire) and good chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is greater than 10 volts at both test points, go to next step. If voltage is not greater than 10 volts at either test point, repair open or short to ground in suspect power feed circuit between main relay and main fuse block located in engine compartment. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  9. Turn ignition off and reconnect main relay 6-pin electrical harness connector. Turn ignition on. Backprobing, measure voltage on Yellow/Blue wires between 31-pin ECM electrical harness connector B137 terminals No. 2 and 3 and good chassis ground point. (Scheme 13) If voltage is greater than 10 volts, check ignition control system. See «IGNITION SYSTEMS»(ref-157416-S12337035572003081200000). If voltage is not greater than 10 volts, repair open or short to ground in suspect wires between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

FUEL SYSTEMS

Note. Basic diagnosis of fuel system should begin by checking fuel pump operation and fuel pressure.

FUEL SYSTEM PRESSURE RELEASE

WARNINGALWAYS release fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components.

Baja, Legacy & Outback

Turn ignition off. Disconnect electrical harness connector from fuel pump relay. Fuel pump relay is located under left side of instrument panel, to right of fuse block. (Scheme 14) Start and run engine until it stalls. After engine stalls, crank engine for 5 seconds. Turn ignition off. Reconnect fuel pump relay connector.

Scheme 14

Scheme 14: Baja, Legacy & Outback
Scheme 14: Baja, Legacy & Outback

Forester, Impreza & Outback Sport

Turn ignition off. Disconnect electrical harness connector from fuel pump relay. Fuel pump relay is a round relay located under right side of instrument panel. (Scheme 15)and (Scheme 16). Start and run engine until it stalls. After engine stalls, crank engine for 5 seconds. Turn ignition off. Reconnect fuel pump relay connector.

Scheme 15

Scheme 15: Forester, Impreza & Outback Sport
Scheme 15: Forester, Impreza & Outback Sport

Scheme 16

Scheme 16
Scheme 16

FUEL PUMP CIRCUIT TESTS

Note. Fuel pump operation can also be checked using Subaru Select Monitor (function mode: FD01). See COMPULSORY VALVE OPERATION CHECK MODE in appropriate SELF-DIAGNOSTICS article.

Scheme 17

Scheme 17: Baja, Forester, Impreza 2.5L, Legacy, Outback 2.5L & Outback Sport
Scheme 17: Baja, Forester, Impreza 2.5L, Legacy, Outback 2.5L & Outback Sport

Scheme 18

Scheme 18
Scheme 18

Scheme 19

Scheme 19
Scheme 19
  1. Turn ignition on and listen for sound of fuel pump operation. If fuel pump operates for 2 seconds when ignition is turned on, check fuel injector circuit. See «FUEL INJECTOR CIRCUIT»(ref-157416-S04665230132003081200000). If fuel pump does not operate for 2 seconds when ignition is turned on, go to next step.
  2. Turn ignition off. Remove fuel pump access hole cover located under right rear side of luggage compartment floor on Baja, Legacy and Outback 2.5L (under right side of rear seat on Forester, Impreza 2.5L and Outback Sport). Disconnect 6-pin electrical harness connector from fuel pump. Using a DVOM, measure resistance between a good chassis ground point and harness side of fuel pump 6-pin electrical harness connector terminal No. 1 (Yellow/Black wire) on Baja, Legacy and Outback 2.5L (terminal No. 4 - Black wire on Forester, Impreza 2.5L and Outback Sport). (Scheme 17)and (Scheme 18). If resistance less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in harness between fuel pump connector and chassis ground point located under right front seat (behind center of instrument panel on Impreza 2.5L and Outback Sport). Also check contact of terminals in connectors between fuel pump and chassis ground point. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  3. Turn ignition on. Using a DVOM, measure voltage between harness side of fuel pump 6-pin electrical harness connector terminal No. 2 (Yellow/Red wire) on Baja, Legacy and Outback 2.5L (terminal No. 1 - Black/Yellow wire on Forester, Impreza 2.5L and Outback Sport) and good chassis ground point. (Scheme 17)and (Scheme 18). If voltage is not greater than 10 volts, go to next step. If voltage is greater than 10 volts, replace fuel pump.
  4. Turn ignition off. Disconnect 4-pin electrical harness connector from fuel pump relay and leave fuel pump connector disconnected. Using a DVOM, measure resistance between harness side of fuel pump 6-pin electrical harness connector terminal No. 2 (Yellow/Red wire) and harness side of fuel pump relay 4-pin electrical harness connector terminal No. 4 (Black wire) on Baja, Legacy and Outback 2.5L. On Forester, Impreza 2.5L and Outback Sport, measure resistance of Black/Yellow wire between harness side of fuel pump 6-pin electrical harness connector terminal No. 1 and harness side of fuel pump relay 4-pin electrical harness connector terminal No. 4. (Scheme 17)and (Scheme 18). If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in harness between fuel pump and fuel pump relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off and leave fuel pump and fuel pump relay connectors disconnected. Using a DVOM, measure resistance between harness side of fuel pump 6-pin electrical harness connector terminal No. 2 (Yellow/Red wire) on Baja, Legacy and Outback 2.5L (terminal No. 1 - Black/Yellow wire on Forester, Impreza 2.5L and Outback Sport) and good chassis ground point. If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short circuit in harness between fuel pump and fuel pump relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Remove fuel pump relay. Using jumper wires, connect battery voltage to fuel pump relay terminals No. 1 and 3. Measure resistance between fuel pump relay terminals No. 2 and 4. (Scheme 19) If resistance is less than 10 ohms, go to next step. If resistance is not less than 10 ohms, replace fuel pump relay.
  7. Turn ignition off. Locate ECM and disconnect 35-pin electrical harness connector B134 (B137 on Forester, Impreza 2.5L and Outback Sport). On Baja, Legacy and Outback 2.5L, use a DVOM to measure resistance of Light Green wire between harness side of ECM 35-pin electrical harness connector B134 terminal No. 11 and harness side of fuel pump relay 4-pin electrical harness connector terminal No. 3. On Forester, use a DVOM to measure resistance of Light Green/Black wire between harness side of ECM 35-pin electrical harness connector B137 terminal No. 11 and harness side of fuel pump relay 4-pin electrical harness connector terminal No. 3. On Impreza 2.5L and Outback Sport, use a DVOM to measure resistance of Light Green/Black wire between harness side of ECM 35-pin electrical harness connector B137 terminal No. 11 and harness side of fuel pump relay 4-pin electrical harness connector terminal No. 3. (Scheme 10), (Scheme 11) and (Scheme 19). If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in harness between ECM and fuel pump relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  8. Check for poor contact of terminals in connectors between ECM and fuel pump relay. If poor contact exists in any connector, repair as required. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If poor contact does not exist, check fuel injector circuit. See «FUEL INJECTOR CIRCUIT»(ref-157416-S04665230132003081200000).

Impreza WRX 2.0L & Outback 3.0L

Turn ignition on and listen for sound of fuel pump operation. If fuel pump operates for 2 seconds when ignition is turned on, check fuel injector circuit. See FUEL INJECTOR CIRCUIT . If fuel pump does not operate for 2 seconds when ignition is turned on, check for diagnostic trouble codes (DTCs). See appropriate SELF-DIAGNOSTICS article.

Baja, Forester, Impreza 2.5L, Legacy, Outback 2.5L & Outback Sport

  1. Crank engine while using a screwdriver or stethoscope to check each fuel injector for a clicking sound. If all fuel injectors click during cranking, injectors are okay, check fuel system pressure. See «FUEL PRESSURE TEST»(ref-157416-S17010386082003081200000). If any fuel injector does not click during cranking, go to next step.
  2. Turn ignition off. Disconnect 2-pin electrical harness connector from each fuel injector one at a time. Turn ignition on. Using a DVOM, measure voltage of Yellow wire between fuel injector 2-pin electrical harness connector terminal No. 2 and good engine ground point. If voltage is more than 10 volts at each fuel injector harness connector, go to next step. If voltage is not more than 10 volts at any fuel injector, repair open circuit in harness between main relay and identified fuel injector. Also check for poor contact in all connectors between main relay and identified fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  3. Turn ignition off. Locate ECM and disconnect 35-pin electrical harness connector B134 (B137 on Forester, Impreza 2.5L and Outback Sport). Using a DVOM, measure resistance of wire between specified terminal on harness side of ECM 35-pin electrical harness connector B134 (B137 on Forester, Impreza 2.5L and Outback Sport) and specified terminal on harness side of fuel injector 2-pin electrical harness connector. See «ECM-TO-FUEL INJECTOR TEST POINTS (BAJA, FORESTER, IMPREZA 2.5L, LEGACY, OUTBACK 2.5L & OUTBACK SPORT)»(ref-157416-S25640661732003110700000) table. (Scheme 10)and (Scheme 11). If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in harness between ECM and identified fuel injector. Also check for poor contact in all connectors between ECM and identified fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. Leave ECM and fuel injector connectors disconnected. Using a DVOM, measure resistance between specified terminal on harness side of ECM 35-pin electrical harness connector B134 (B137 on Forester, Impreza 2.5L and Outback Sport) and good chassis ground point. See «ECM-TO-FUEL INJECTOR TEST POINTS (BAJA, FORESTER, IMPREZA 2.5L, LEGACY, OUTBACK 2.5L & OUTBACK SPORT)»(ref-157416-S25640661732003110700000) table. (Scheme 10)and (Scheme 11). If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short circuit in harness between ECM and fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off. With 2-pin electrical harness connector disconnected at each fuel injector, measure resistance across fuel injector terminals. If resistance is 5-20 ohms, go to next step. If resistance is not 5-20 ohms, replace faulty fuel injector.
  6. Check for poor contact of terminals in connectors between ECM and fuel injectors. If poor contact exists in any connector, repair as required. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If poor contact does not exist, go to «TROUBLE SHOOTING - NO CODES»(ref-157458) article. ECM-TO-FUEL INJECTOR TEST POINTS (BAJA, FORESTER, IMPREZA 2.5L, LEGACY, OUTBACK 2.5L & OUTBACK SPORT) Application, ECM Harness Connector & Terminal No. ECM Harness Connector Wire Color Fuel Injector No. (1) Fuel Injector Harness Connector Terminal No. 1 Wire Color Baja, Legacy & Outback 35-Pin B134 34 Pink 1 Brown/White 23 Pink/Blue 2 Light Green 22 Pink/Black 3 Brown/Light Blue 8 Pink/Green 4 Brown/White Forester 35-Pin B137 34 Pink 1 Brown 23 Pink/Blue 2 Light Green 22 Pink/Black 3 Green/Orange 8 Pink/Green 4 Green/Black Impreza 2.5L 35-Pin B137 34 Pink 1 Brown/White 23 Pink/Blue 2 Light Green 22 Pink/Black 3 Green/Orange 8 Pink/Green 4 Green/Black (1) Wire changes color at Brown 16-pin connector located at top front of engine.

Impreza WRX 2.0L

  1. Crank engine while using a screwdriver or stethoscope to check each fuel injector for a clicking sound. If all fuel injectors click during cranking, injectors are okay, check fuel system pressure. See «FUEL PRESSURE TEST»(ref-157416-S17010386082003081200000). If any fuel injector does not click during cranking, go to next step.
  2. Turn ignition off. Disconnect 2-pin electrical harness connector from each fuel injector one at a time. Turn ignition on. Using a DVOM, measure voltage of Red wire between fuel injector 2-pin electrical harness connector terminal No. 2 and good engine ground point. If voltage is more than 10 volts at each fuel injector harness connector, go to next step. If voltage is not more than 10 volts at any fuel injector, repair open circuit in harness between main relay and identified fuel injector. Also check for poor contact in all connectors between main relay and identified fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  3. Turn ignition off. Locate ECM and disconnect 24-pin electrical harness connector B136 and 31-pin electrical harness connector B137. Using a DVOM, measure resistance of wire between specified terminal on harness side of specified ECM electrical harness connector and specified terminal on harness side of fuel injector 2-pin electrical harness connector. See «ECM-TO-FUEL INJECTOR TEST POINTS (IMPREZA WRX 2.0L)»(ref-157416-S29430317202003110700000) table. (Scheme 12) If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in harness between ECM and identified fuel injector. Also check for poor contact in all connectors between ECM and identified fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. Leave ECM and fuel injector connectors disconnected. Using a DVOM, measure resistance between specified terminal on harness side of specified ECM electrical harness connector and good chassis ground point. See «ECM-TO-FUEL INJECTOR TEST POINTS (IMPREZA WRX 2.0L)»(ref-157416-S29430317202003110700000) table. (Scheme 12) If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short circuit in harness between ECM and fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off. With 2-pin electrical harness connector disconnected at each fuel injector, measure resistance across fuel injector terminals. If resistance is 5-20 ohms, go to next step. If resistance is not 5-20 ohms, replace faulty fuel injector.
  6. Check for poor contact of terminals in connectors between ECM and fuel injectors. If poor contact exists in any connector, repair as required. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If poor contact does not exist, go to «TROUBLE SHOOTING - NO CODES»(ref-157458) article. ECM-TO-FUEL INJECTOR TEST POINTS (IMPREZA WRX 2.0L) ECM Harness Connector & Terminal No. ECM Harness Connector Wire Color Fuel Injector No. (1) Fuel Injector Harness Connector Terminal No. 1 Wire Color 31-Pin B137 1 Pink 1 Green/White 24-Pin B136 6 Pink/Blue 2 Blue/White 5 Pink/Black 3 White 4 Pink/Green 4 Yellow/White (1) Wire changes color at Brown 16-pin connector located at left front corner of engine compartment in front of main fuse box.

Outback 3.0L

  1. Crank engine while using a screwdriver or stethoscope to check each fuel injector for a clicking sound. If all fuel injectors click during cranking, injectors are okay, check fuel system pressure. See «FUEL PRESSURE TEST»(ref-157416-S17010386082003081200000). If any fuel injector does not click during cranking, go to next step.
  2. Turn ignition off. Disconnect 2-pin electrical harness connector from each fuel injector one at a time. Turn ignition on. Using a DVOM, measure voltage of Yellow/Blue wire between fuel injector 2-pin electrical harness connector terminal No. 2 and good engine ground point. If voltage is more than 10 volts at each fuel injector harness connector, go to next step. If voltage is not more than 10 volts at any fuel injector, repair open circuit in harness between main relay and identified fuel injector. Also check for poor contact in all connectors between main relay and identified fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  3. Turn ignition off. Locate ECM and disconnect 24-pin electrical harness connector B136 and 31-pin electrical harness connector B137. Using a DVOM, measure resistance of wire between specified terminal on harness side of specified ECM electrical harness connector and specified terminal on harness side of fuel injector 2-pin electrical harness connector. See «ECM-TO-FUEL INJECTOR TEST POINTS (OUTBACK 3.0L)»(ref-157416-S12753619992003110700000) table. (Scheme 13) If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in harness between ECM and identified fuel injector. Also check for poor contact in all connectors between ECM and identified fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. Leave ECM and fuel injector connectors disconnected. Using a DVOM, measure resistance between specified terminal on harness side of specified ECM electrical harness connector and good chassis ground point. See «ECM-TO-FUEL INJECTOR TEST POINTS (OUTBACK 3.0L)»(ref-157416-S12753619992003110700000) table. (Scheme 13) If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short circuit in harness between ECM and fuel injector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off. With 2-pin electrical harness connector disconnected at each fuel injector, measure resistance across fuel injector terminals. If resistance is 5-20 ohms, go to next step. If resistance is not 5-20 ohms, replace faulty fuel injector.
  6. Check for poor contact of terminals in connectors between ECM and fuel injectors. If poor contact exists in any connector, repair as required. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If poor contact does not exist, go to «TROUBLE SHOOTING - NO CODES»(ref-157458) article. ECM-TO-FUEL INJECTOR TEST POINTS (OUTBACK 3.0L) ECM Harness Connector & Terminal No. ECM Harness Connector Wire Color Fuel Injector No. (1) Fuel Injector Harness Connector Terminal No. 1 Wire Color 31-Pin B137 1 Pink 1 Brown 24-Pin B136 6 Pink/Blue 2 Light Green 5 Pink/Black 3 Blue/Red 4 Pink/Green 4 Blue/Black 3 Violet 5 Brown/White 1 Violet/White 6 Green/Red (1) Wire changes color at Brown 16-pin connector located at top front of engine.

Scheme 20

Scheme 20: Baja, Forester, Impreza 2.5L, Legacy, Outback 2.5L & Outback Sport
Scheme 20: Baja, Forester, Impreza 2.5L, Legacy, Outback 2.5L & Outback Sport

Scheme 21

Scheme 21
Scheme 21
  1. Remove and inspect all spark plugs. If spark plugs are okay, reinstall all spark plugs and go to next step. If spark plugs are not okay, replace as necessary.
  2. Check ignition system for spark. Remove plug wire from each spark plug. DO NOT remove spark plug from cylinder. Install new spark plug or spark plug tester to each plug wire. Make contact of thread portion of spark plug with engine. While opening throttle valve fully, crank engine to check that spark occurs at each cylinder. If spark occurs at each cylinder, check fuel pump system. See «FUEL PUMP CIRCUIT TESTS»(ref-157416-S14956756052003081200000) under FUEL SYSTEMS. If spark does not occur at each cylinder, go to next step.
  3. Remove spark plug cables and check resistance of each cable. See «HIGH TENSION WIRE RESISTANCE»(ref-157416-S02677951842003111000000) table. Replace spark plug cables if resistance is not within specification. If spark plug cables are okay, go to next step. HIGH TENSION WIRE RESISTANCE Application Ohms No. 1 Spark Plug Cable 5600-10,600 No. 2 Spark Plug Cable 7300-13,700 No. 3 Spark Plug Cable 5900-11,100 No. 4 Spark Plug Cable 7300-13,700
  4. Turn ignition off. Disconnect 4-pin electrical harness connector from ignition coil and ignitor assembly. Turn ignition on. Using a DVOM, measure power supply voltage of Yellow/Black wire (Yellow/White wire on Forester, Impreza 2.5L and Outback Sport) between harness side of ignition coil and ignitor assembly 4-pin electrical harness connector terminal No. 2 and good engine ground point. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open circuit in harness between ignition coil and ignitor assembly and ignition switch. Note that wire changes color to Green/Red on all models at Brown 16-pin connector located at top front of engine. Also check for poor contact in all connectors between ignition coil and ignitor assembly and ignition switch. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off and leave 4-pin ignition coil and ignitor assembly electrical harness connector disconnected. Using a DVOM, measure ground circuit resistance of Black wire (Green/White wire on Forester, Impreza 2.5L and Outback Sport) between harness side of ignition coil and ignitor assembly 4-pin electrical harness connector terminal No. 3 and good engine ground point. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in harness between ignition coil and ignitor assembly and engine ground point located at right rear of engine. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Turn ignition off. Remove ignition coil and ignitor assembly. Using a DVOM, check primary resistance between ignition coil and ignitor assembly terminals No. 1 and 2 for one coil and terminals No 2. and 4 for remaining coil. (Scheme 20) See «IGNITION COIL RESISTANCE - OHMS @ 68°F (20°C)»(ref-157416-S39069641152003111000000) table. If primary resistance is as specified, go to next step. If primary resistance is not as specified, replace ignition coil and ignitor assembly.
  7. Check secondary resistance. To test secondary resistance, connect DVOM between ignition coil and ignitor assembly secondary terminals No. 1 and 2, and terminals No. 3 and 4. (Scheme 21) See «IGNITION COIL RESISTANCE - OHMS @ 68°F (20°C)»(ref-157416-S39069641152003111000000) table. If secondary resistance is as specified, go to next step. If secondary resistance is not as specified, replace ignition coil and ignitor assembly. IGNITION COIL RESISTANCE - OHMS @ 68°F (20°C) Application Primary (1) (2) Secondary Baja, Forester, Impreza 2.5L, Legacy, Outback 2.5L & Outback Sport 0.66-0.80 10,880-14,720 (1) Measured between ignition coil and ignitor assembly 4-pin terminals No. 1 and 2, and between terminals No. 2 and 4. (Scheme 20) (2) Measured between ignition coil and ignitor assembly secondary terminals for cylinders No. 1 and 2 and cylinders No. 3 and 4. (Scheme 21) Insulation resistance between primary terminal and case should be 100 megohms or more.
  8. Turn ignition off. Reconnect 4-pin ignition coil and ignitor assembly electrical harness connector. While cranking engine, monitor voltage on Red/Dark Green wire (Red/Green wire on Forester, Impreza 2.5L and Outback Sport) by backprobing between 4-pin ignition coil and ignitor assembly electrical harness connector terminal No. 1 and good engine ground point. Also monitor voltage on Blue/Black wire (Blue wire on Forester, Impreza 2.5L and Outback Sport) by backprobing between 4-pin ignition coil and ignitor assembly electrical harness connector terminal No. 4 and good engine ground point. Voltage should vary synchronously with engine speed. If voltage is greater than 10 volts at both test points, go to next step. If voltage is not greater than 10 volts at either test point, replace ignition coil and ignitor assembly.
  9. Turn ignition off. Locate ECM and disconnect 35-pin electrical harness connector B134 (B137 on Forester, Impreza 2.5L and Outback Sport). Disconnect ignition coil and ignitor assembly 4-pin electrical harness connector. Using a DVOM, measure resistance of wire between specified terminal on harness side of ECM electrical harness connector and backprobe specified terminal on harness side of ignition coil and ignitor assembly 4-pin electrical harness connector. See «ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (BAJA, FORESTER, IMPREZA 2.5L, LEGACY, OUTBACK 2.5L & OUTBACK SPORT)»(ref-157416-S22735009992003111000000) table. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in harness between ECM and ignition coil and ignitor assembly. Also check for poor contact in all connectors between ECM and ignition coil and ignitor assembly. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  10. Leave ECM and ignition coil and ignitor assembly electrical harness connectors disconnected. Using a DVOM, measure resistance between specified terminal on harness side of ECM electrical harness connector and good chassis ground point. See «ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (BAJA, FORESTER, IMPREZA 2.5L, LEGACY, OUTBACK 2.5L & OUTBACK SPORT)»(ref-157416-S22735009992003111000000) table. If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short circuit in harness between ECM and ignition coil and ignitor assembly. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  11. Check for poor contact of terminals in connectors between ECM and ignition coil and ignitor assembly. If poor contact exists in any connector, repair as required. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If poor contact does not exist, check fuel pump circuit. See «FUEL PUMP CIRCUIT TESTS»(ref-157416-S14956756052003081200000) under FUEL SYSTEMS. ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (BAJA, FORESTER, IMPREZA 2.5L, LEGACY, OUTBACK 2.5L & OUTBACK SPORT) Application, ECM Harness Connector & Terminal No. ECM Harness Connector Wire Color Ignition Coil & Ignitor Assembly Terminal No. (1) Ignition Coil & Ignitor Assembly Terminal Wire Color Baja, Legacy & Outback 35-Pin B134 32 Red/Black 4 Blue/Black 33 Red/Yellow 1 Red/Dark Green Forester, Impreza 2.5L & Outback Sport 35-Pin B137 32 Green/White 4 Blue 33 Yellow/Blue 1 Red/Green (1) Wire changes color at Brown 16-pin connector located at top front of engine.
  1. Remove and inspect all spark plugs. If spark plugs are okay, reinstall all spark plugs and go to next step. If spark plugs are not okay, replace as necessary.
  2. Check ignition system for spark. Remove plug wire from each spark plug. DO NOT remove spark plug from cylinder. Install new spark plug or spark plug tester to each plug wire. Make contact of thread portion of spark plug with engine. While opening throttle valve fully, crank engine to check that spark occurs at each cylinder. If spark occurs at each cylinder, check fuel pump system. See «FUEL PUMP CIRCUIT TESTS»(ref-157416-S14956756052003081200000) under FUEL SYSTEMS. If spark does not occur at each cylinder, go to next step.
  3. Turn ignition off. Disconnect 3-pin electrical harness connector from ignition coil and ignitor assembly at each cylinder. Turn ignition on. Using a DVOM, measure power supply voltage of Red/Yellow wire between harness side of each ignition coil and ignitor assembly 3-pin electrical harness connector terminal No. 3 and good engine ground point. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open circuit in harness between identified ignition coil and ignitor assembly and ignition switch. Note that wire changes color to Green/Red at Brown 16-pin connector located at left front corner of engine compartment, in front of main fuse box. Also check for poor contact in all connectors between ignition coil and ignitor assemblies and ignition switch. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. Turn ignition off and leave 3-pin ignition coil and ignitor assembly electrical harness connectors disconnected. Using a DVOM, measure ground circuit resistance of Black/Yellow wire between harness side of each ignition coil and ignitor assembly 3-pin electrical harness connector terminal No. 2 and good engine ground point. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in harness between identified ignition coil and ignitor assembly and engine ground point located at top left side of engine. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off and leave 3-pin ignition coil and ignitor assembly electrical harness connectors disconnected. Locate ECM and disconnect 24-pin electrical harness connector B136. Using a DVOM, measure resistance of wire between specified terminal on harness side of ECM 24-pin electrical harness connector B136 and specified terminal on harness side of each ignition coil and ignitor assembly 3-pin electrical harness connector. See «ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (IMPREZA WRX 2.0L)»(ref-157416-S38546123422003111000000) table. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in harness between ECM and identified ignition coil and ignitor assembly. Also check for poor contact in all connectors between ECM and ignition coil and ignitor assemblies. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Leave ECM and ignition coil and ignitor assembly electrical harness connectors disconnected. Using a DVOM, measure resistance between specified terminal on harness side of ECM 24-pin electrical harness connector B136 and good chassis ground point. See «ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (IMPREZA WRX 2.0L)»(ref-157416-S38546123422003111000000) table. If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short circuit in harness between ECM and identified ignition coil and ignitor assembly. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  7. Check for poor contact of terminals in connectors between ECM and ignition coil and ignitor assemblies. If poor contact exists in any connector, repair as required. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If poor contact does not exist, check fuel pump circuit. See «FUEL PUMP CIRCUIT TESTS»(ref-157416-S14956756052003081200000) under FUEL SYSTEMS. ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (IMPREZA WRX 2.0L) ECM Harness Connector & Terminal No. ECM Harness Connector Wire Color Cylinder No. (1) Ignition Coil & Ignitor Assembly Terminal No. 1 Wire Color 24-Pin B136 21 Yellow/Green 4 Yellow 22 Yellow/Red 3 White/Yellow 23 Yellow/Black 2 Blue/Yellow 24 Yellow 1 Green/Yellow (1) Wire changes color at Brown 16-pin connector located at left front corner of engine compartment in front of main fuse box.
  1. Remove and inspect all spark plugs. If spark plugs are okay, reinstall all spark plugs and go to next step. If spark plugs are not okay, replace as necessary.
  2. Check ignition system for spark. Remove plug wire from each spark plug. DO NOT remove spark plug from cylinder. Install new spark plug or spark plug tester to each plug wire. Make contact of thread portion of spark plug with engine. While opening throttle valve fully, crank engine to check that spark occurs at each cylinder. If spark occurs at each cylinder, check fuel pump system. See «FUEL PUMP CIRCUIT TESTS»(ref-157416-S14956756052003081200000) under FUEL SYSTEMS. If spark does not occur at each cylinder, go to next step.
  3. Turn ignition off. Disconnect 3-pin electrical harness connector from ignition coil and ignitor assembly at each cylinder. Turn ignition on. Using a DVOM, measure power supply voltage of Black/White wire between harness side of each ignition coil and ignitor assembly 3-pin electrical harness connector terminal No. 3 and good engine ground point. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open circuit in harness between identified ignition coil and ignitor assembly and ignition switch. Note that wire changes color to Green/Red at Brown 16-pin connector located at top front of engine. Also check for poor contact in all connectors between ignition coil and ignitor assemblies and ignition switch. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  4. Turn ignition off and leave 3-pin ignition coil and ignitor assembly electrical harness connectors disconnected. Using a DVOM, measure ground circuit resistance of White/Green wire (Black/White wire on cylinders No. 3 and 5) between harness side of each ignition coil and ignitor assembly 3-pin electrical harness connector terminal No. 2 and good engine ground point. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in harness between identified ignition coil and ignitor assembly and engine ground point located at right rear of engine. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  5. Turn ignition off and leave 3-pin ignition coil and ignitor assembly electrical harness connectors disconnected. Locate ECM and disconnect 24-pin electrical harness connector B136. Using a DVOM, measure resistance of wire between specified terminal on harness side of ECM 24-pin electrical harness connector B136 and specified terminal on harness side of each ignition coil and ignitor assembly 3-pin electrical harness connector. See «ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (OUTBACK 3.0L)»(ref-157416-S41610023082003111000000) table. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in harness between ECM and identified ignition coil and ignitor assembly. Also check for poor contact in all connectors between ECM and ignition coil and ignitor assemblies. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  6. Leave ECM and ignition coil and ignitor assembly electrical harness connectors disconnected. Using a DVOM, measure resistance between specified terminal on harness side of ECM 24-pin electrical harness connector B136 and good chassis ground point. See «ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (OUTBACK 3.0L)»(ref-157416-S41610023082003111000000) table. If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short circuit in harness between ECM and identified ignition coil and ignitor assembly. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
  7. Turn ignition off. Reconnect 3-pin ignition coil and ignitor assembly and ECM electrical harness connectors. While cranking engine, monitor voltage on specified wire by backprobing between each 3-pin ignition coil and ignitor assembly electrical harness connector terminal No. 1 and good engine ground point for each cylinder. See «ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (OUTBACK 3.0L)»(ref-157416-S41610023082003111000000) table. Voltage should vary synchronously with engine speed. If voltage is greater than 10 volts at all test points, go to next step. If voltage is not greater than 10 volts at any test point, replace identified ignition coil and ignitor assembly.
  8. Check for poor contact of terminals in connectors between ECM and ignition coil and ignitor assemblies. If poor contact exists in any connector, repair as required. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If poor contact does not exist, check fuel pump circuit. See «FUEL PUMP CIRCUIT TESTS»(ref-157416-S14956756052003081200000) under FUEL SYSTEMS. ECM-TO-IGNITION COIL & IGNITOR ASSEMBLY TEST POINTS (OUTBACK 3.0L) ECM Harness Connector & Terminal No. ECM Harness Connector Wire Color Cylinder No. Ignition Coil & Ignitor Assembly Terminal No. 1 Wire Color 24-Pin B136 19 Blue 6 Blue 20 Yellow 5 Yellow 21 Green 4 Green 22 Red 3 Red 23 Black 2 Black 24 White 1 White

IDLE SPEED & IGNITION TIMING

Ensure idle speed and ignition timing are set to specification. See IDLE SPEED SPECIFICATIONS and IGNITION TIMING (DEGREES BTDC @ IDLE) tables.

ApplicationRPM
2.0L
With A/C Off750 +/- 100
With A/C On
A/T825 +/- 150
M/T800 +/- 150
2.5L
With A/C Off
A/T700 +/- 100
M/T650 +/- 100
With A/C On850 +/- 100
3.0L
With A/C Off600 +/- 50
With A/C On700 +/- 50

IDLE SPEED SPECIFICATIONS

Application(1) Auto. Trans.(1) Man. Trans.
2.0L12 @ 700 RPM12 @ 750 RPM
2.5L15 @ 700 RPM10 @ 650 RPM
3.0L (2)10 @ 600 RPM(3)
(1) To improve stability, timing is controlled while engine is idling. Timing range is plus or minus 8 degrees (3 degrees on 2.0L). (2) Timing must be checked using a scan tool. (3) Manual transmission is not available with 3.0L engine.
(1)To improve stability, timing is controlled while engine is idling. Timing range is plus or minus 8 degrees (3 degrees on 2.0L).
(2)Timing must be checked using a scan tool.
(3)Manual transmission is not available with 3.0L engine.

IGNITION TIMING (DEGREES BTDC @ IDLE)

More articles — Engine Controls - Basic Diagnostic Procedures