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Engine Controls - Basic Testing: Other Isuzu Amigo II

Testing & Diagnostics ~13029 words

Compression

Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. If compression gauge is used, see COMPRESSION SPECIFICATIONS . If vacuum gauge is used, check for low or unstable vacuum condition. If engine analyzer is used, see manufacturer's manual for specific instructions.

WARNINGDO NOT use ignition switch during compression tests on fuel injected vehicles. Use a remote starter switch to crank engine. Fuel injectors on many models are triggered by ignition switch during cranking mode, which can create a fire hazard or contaminate the engine's oiling system.

ENGINE COMPRESSION

ApplicationPressure (Minimum)
Amigo, Rodeo, Passport, Trooper and SLX
2.2L(1)
3.2L & 3.5L145 psi (10.2 kg/cm 2 )
Hombre1100 psi (7.0 kg/cm 2 )
(1) Maximum pressure difference between any 2 cylinders is 14.5 psi (1.02 kg/cm 2 ).
(1)Maximum pressure difference between any 2 cylinders is 14.5 psi (1.02 kg/cm 2 ).

COMPRESSION SPECIFICATIONS

Exhaust System Backpressure

The exhaust system can be checked with a vacuum or pressure gauge. If using a pressure gauge, remove oxygen sensor or air injection check valve (if equipped). Connect a 0-5 psi pressure gauge and run engine at 2000 RPM. If exhaust system backpressure is greater than 2 psi, exhaust system or catalytic converter is plugged.

If a vacuum gauge is used, connect vacuum gauge hose to intake manifold vacuum port and start engine. Open throttle part way and hold. Observe vacuum gauge. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restriction.

FUEL SYSTEM

WARNINGAlways relieve fuel pressure before disconnecting any fuel injection related component. DO NOT allow fuel to contact engine or electrical components.

FUEL SYSTEM PRESSURE RELEASE

  1. Loosen fuel tank filler cap to relieve tank pressure. Remove fuel pump relay from underhood fuse/relay box (Amigo, Rodeo, Passport, Trooper and SLX), or from behind glove box (Hombre). Start and operate engine until it stalls. Crank engine an additional 30 seconds.
  2. Loosen hose clamp of fuel line on side of pressure regulator, coming from fuel line inlet distributor pipe. Cover fuel hose with a shop towel, and slowly pull hose from pressure regulator to relieve fuel pressure. When fuel stops leaking, reinstall hose and clamp.

IGNITION SYSTEM

Hombre 4.3L is only model equipped with distributor. All other applications use Distributorless Ignition System (DIS). Distributor specifications are available at time of publication.

IGNITION COIL

Application (1)Primary OhmsSecondary Ohms
Amigo, Rodeo & Passport
2.2L.81-189000-12,000
3.2LN/AN/A
HombreN/A5000-25,000
Trooper & SLXN/AN/A
(1) Insulation resistance should not be more than 10 megohms.
(1)Insulation resistance should not be more than 10 megohms.

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

IDLE SPEED

ApplicationRPM
Amigo, Rodeo & Passport
2.2L (1)800
3.2L (2)750
Hombre
2.2L(2) (3)
4.3L650
Trooper & SLX (2)750
(1) Transmission in Park or Neutral. (2) Idle speed is controlled by PCM and is not adjustable. (3) Idle speed specification is available at time of publication.
(1)Transmission in Park or Neutral.
(2)Idle speed is controlled by PCM and is not adjustable.
(3)Idle speed specification is available at time of publication.

IDLE SPEED SPECIFICATIONS

IGNITION TIMING

Note. All models are equipped with electronic computer-controlled ignition system. Ignition timing is not adjustable.

MALFUNCTION INDICATOR LIGHT (MIL) INOPERATIVE

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Attempt to start engine. If engine does not start, go to step 6). If engine starts, go to next step.
  3. Check METER fuse (15-amp) located in underhood fuse box. If fuse is okay, go to next step. If fuse is blown, go to step 16).
  4. Turn ignition on. Using test light connected to ground, 0probe ignition feed circuit at instrument cluster terminal No. 9 (Yellow wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 13).
  5. Turn ignition off. Disconnect PCM electrical connectors. Connect a jumper wire between ground and MIL control circuit at PCM 36-pin, Red connector terminal A13 (White/Green wire). Turn ignition on. If MIL comes on, go to step 10). If MIL does not come on, go to step 11).
  6. Check ENGINE fuse (15-amp) located in dash fuse box. Check PCM fuse EB-12 (15-amp) in fuse/relay box located in engine compartment. If fuses are okay, go to next step. If fuses are blown, go to step 15).
  7. Turn ignition off. Disconnect PCM electrical connectors. Turn ignition on. Using test light connected to ground, probe ignition feed circuits at PCM 36-pin, Blue connector terminals E16 and F16 (Red/Blue wires). If test light illuminates, go to next step. If test light does not illuminate, go to step 12).
  8. Using test light connected to ground, probe battery feed circuit at PCM 36-pin, Red connector terminal A4 (Red/White wire). If test light does not illuminate, go to step 14). If test light illuminates, go to next step.
  9. Check for faulty PCM ground connections. Repair as necessary. Retest system. If connections are okay, go to next step.
  10. Check PCM connectors for damaged terminals. If any terminals are damaged, repair terminals as necessary. Retest system. If PCM connector terminals are okay, go to step 17).
  11. Check for an open in MIL control circuit (White/Green wire) between PCM and MIL. Repair as necessary. Retest system. If circuit is okay, go to step 18).
  12. Substitute PCM main relay with a known-good relay. PCM main relay is located in fuse/relay box in engine compartment. Observe MIL. If MIL operates properly, replace PCM main relay. Retest system. If MIL still does not operate, go to next step.
  13. Repair open in ignition feed circuit (Black/Yellow wire) between PCM main relay and dash fuse box. Retest system.
  14. Repair open in PCM battery feed circuit (Red/White wire) between PCM and fuse/relay box located in engine compartment. Retest system.
  15. Repair short to ground in PCM ignition feed circuit (Black/Yellow or Red/Blue wire) or PCM battery feed circuit (Red/White wire). See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. Retest system. Replace fuse.
  16. Repair the short to ground in ignition feed circuit (Yellow wire) between instrument cluster and dash fuse box. Retest system. Replace fuse.
  17. Replace PCM. Reprogram PCM. Verify proper system operation. Retest system.
  18. Check MIL driver circuit (White/Green wire) for poor connection at instrument cluster connector. Repair as necessary. Retest system. If no problem is found, diagnose problem in instrument cluster. See «INSTRUMENT PANELS»(ref-26406) article in ACCESSORIES/SAFETY EQUIP section.

MIL ON STEADY

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM electrical connectors. Turn ignition on. If MIL comes on, go to next step. If MIL does not come on, go to step 5).
  3. Turn ignition off. Disconnect instrument panel cluster connector. Check for short to ground in MIL control circuit (Green wire) between PCM 36-pin, Red connector terminal A13 and instrument panel cluster. Repair as necessary. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES -INTRODUCTION»(ref-16364) article. If circuit is okay, go to next step.
  4. Replace instrument panel cluster. See «INSTRUMENT PANEL»(ref-26406) article in ACCESSORIES/SAFETY EQUIP section. Repeat OBD-II system check.
  5. Turn ignition off. Reconnect PCM electrical connectors. Turn ignition on. Reprogram EEPROM. Using TECH 2 scan tool, command MIL OFF. If MIL did not go off, go to next step. If MIL did go off, repeat OBD-II system check.
  6. Replace PCM. Program PCM. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.

ENGINE CRANKS BUT WILL NOT RUN

WARNINGRelieve fuel pressure before connecting fuel pressure gauge. See FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEM.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Install Tech 2 scan tool. Following manufacturer's instructions, check for stored DTCs. If no DTCs are stored, go to next step. If any DTCs are stored, diagnose DTC. See appropriate TESTS W/CODES - INTRODUCTION articles below: For SLX, Amigo, Rodeo, Trooper and Passport 2.2L, see «TESTS W/CODES»(ref-16367) article. For Hombre 2.2L, see «TESTS W/CODES»(ref-16368) article. For SLX, Amigo, Rodeo, Trooper and Passport 3.2L and 3.5L, see «TESTS W/CODES»(ref-16369) article.
  3. Check IGNITION COIL fuse (15-amp) and ENGINE DEVICE fuse (15-amp) located in dash fuse box. Check PCM fuse (15-amp) located in fuse/relay box in engine compartment. If any fuse is blown, go to next step. If fuses are okay, go to step 5).
  4. Check for short to ground in appropriate circuits. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. Repair as necessary. Replace any blown fuses.
  5. Turn ignition on. With a test light connected to ground, probe IGNITION COIL fuse (15-amp) and ENGINE DEVICE fuse (15-amp) located in dash fuse box and PCM fuse (15-amp) located in fuse/relay box in engine compartment. If test light illuminates at all fuses, go to step 7). If test light does not illuminate at all fuses, go to next step.
  6. Repair open in appropriate ignition feed circuit. Retest system.
  7. Disconnect ignition secondary wire at coil No. 1. Install spark tester at end of secondary wire. While cranking engine, check for crisp, Blue spark. If poor or no spark is found, go to next step. If spark is okay, go to step 16).
  8. Disconnect ignition module harness connector. Check for open or short in Red/Black wire between ignition coil and Ignition Control Module (ICM). If Red/Black wire is okay, go to step 10). If problem is found in Red/Black wire, go to next step.
  9. Repair open or short in Red/Black wire as necessary. Retest system.
  10. Turn ignition on. Using DVOM, measure voltage at Black/Orange wire terminal of ICM harness connector. If battery voltage exists, go to step 12). If battery voltage does not exist, go to next step.
  11. Repair open in Black/Orange wire. Retest system.
  12. Check for open in ICM ground circuit (Black/Red wire). If problem is found, go to next step. If no problem is found, go to step 14)
  13. Locate and repair open in Black/Red wire. Retest system.
  14. Replace ICM. Attempt to start engine. If engine does not start, go to next step.
  15. Replace PCM. Program PCM as required. Retest system.
  16. Turn ignition off. Using DVOM, measure ignition coil primary resistance. If primary resistance is .8-18 ohms, go to next step. If resistance is not as specified, go to step 18).
  17. Measure ignition coil secondary resistance. If secondary resistance is 9000-12,000 ohms, go to step 19). If secondary resistance is not as specified, go to next step.
  18. Replace ignition coil. Retest system.
  19. Measure resistance of each coil-to-spark plug secondary ignition wire. If resistance is greater than 10 k/ohms per foot, go to next step. If resistance is not greater than specification, go to step 21)
  20. Replace any spark plug wires with resistance greater than 10 k/ohms per foot. Verify engine operation. If problem still exists, go to next step.
  21. Remove all spark plugs. Inspect spark plugs for fouling, loose or missing electrodes, or cracked plugs. Clean or replace spark plugs as necessary and go to next step. If spark plugs are okay, go to step 33).
  22. Attempt to start engine. If problem still exists, go to next step.
  23. Turn ignition off. Install fuel pressure gauge to fuel supply line test fitting. Turn ignition on. If fuel pressure is 43-55 psi (2.9-3.9 kg/cm 2 ) and holds steady, go to step 24). If fuel pressure is not 43-55 psi (2.9-3.9 kg/cm 2 ) or does not hold steady, go to next step.
  24. If no fuel pressure is indicated, go to «FUEL SYSTEM DIAGNOSIS»(ref-16362-S30992961432001010800000) . If any fuel pressure is indicated, go to «FUEL SYSTEM ELECTRICAL TEST»(ref-16362-S40688053162001010800000) .
  25. Install Injector Tester (J-39021 ) and switch box at injector test connector, and activate fuel injector. If fuel pressure drops, go to next step. If fuel pressure does not drop, go to «FUEL SYSTEM DIAGNOSIS»(ref-16362-S30992961432001010800000) .
  26. Pressurize system with ignition on. Using injector switch box, test each injector for pressure drop. If a pressure drop exists for each injector, go to next step. If a pressure drop does not exist for each injector, go to «FUEL SYSTEM DIAGNOSIS»(ref-16362-S30992961432001010800000) .
  27. Remove Injector Tester (J-39021 ) and switch box. Connector Injector Test Light (J-39021-45 ) to injector test harness connector. Crank engine. If any tester lights blink while engine is cranking, go to step 33). If no tester lights blink while engine is cranking, go to next step.
  28. Raise and support vehicle. Disconnect Crankshaft Position (CKP) sensor connector. Turn ignition on. Using a test light connected to ground, probe ignition feed circuit at CKP sensor harness terminal No. 1 (Green wire). If test light does not illuminate, repair open Green wire. Retest system. If test light illuminates, go to next step.
  29. Connect test light between ignition feed circuit at CKP sensor harness terminal No. 1 (Green wire) and ground circuit terminal No. 3 (Black wire). If test light does not illuminate, repair open Black wire. Retest system. If test light illuminates, go to next step.
  30. Turn ignition off. Check signal circuit of CKP sensor between CKP sensor and ECM for open or short. If problem is found in CKP signal circuit, repair open or short as necessary. Retest system. If CKP signal circuit is okay, go to step 33).
  31. Replace CKP sensor. Retest system. If problem still exists, go to step 34).
  32. Check for open or short in CKP low circuit (Blue wire) between CKP sensor terminal No. 2 and PCM. If no problem was found, go to next step. If problem was found, repair Blue wire as necessary.
  33. Replace PCM. Program PCM. Retest system.
  34. Test for fuel contamination. If fuel is not contaminated, go to next step. If fuel is contaminated, clean fuel system as necessary. Replace fuel filter and verify all fuel injectors are delivering fuel.
  35. Check for these possible conditions: Faulty or incorrect camshaft timing belt. Leaking or sticking valves or rings. Leaking head gasket. Excessive valve deposits. Loose or worn rocker arms. Weak valve springs. Repair as necessary. See appropriate article in ENGINES section. Retest system.

MULTIPLE PCM INFORMATION SENSOR DTCS SET

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM electrical connectors. Turn ignition on. Check for poor connections, open or short in 5-volt reference circuit for affected sensors. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. If problem is found, go to next step. If circuits are okay, go to step 4).
  3. Repair as necessary. Verify system is operating properly.
  4. Check for poor connections or open in ground circuits of affected sensors. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. If problem is found, go to next step. If connections and circuits are okay, go to step 6).
  5. Repair poor connection or open as necessary. Verify system is operating properly.
  6. Using DVOM, check voltage between ground and EGR pintle position sensor signal circuit at PCM connector A-36 harness terminal B7 (Yellow/Red wire). If no voltage exists, go to next step. If voltage exists, go to step 12).
  7. Using DVOM, check voltage between ground and MAP sensor signal circuit at PCM connector A-38 harness terminal F8 (Gray wire). If voltage exists, go to step 14). If no voltage exists, go to next step.
  8. Using DVOM, check voltage between ground and TP sensor signal circuit at PCM connector A-38 harness terminal E8 (Blue wire). If no voltage exists, go to next step. If voltage exists, go to step 15).
  9. Using DVOM, check voltage between ground and IAT sensor signal circuit at PCM connector A-36 harness terminal B8 (Yellow/Green wire). If no voltage exists, go to next step. If any voltage exists, go to step 16).
  10. Using DVOM, check voltage between ground and ECT sensor signal circuit at PCM connector A-38 harness terminal E9 (Blue/Red wire). If voltage exists, go to step 20). If voltage does not exist, go to step 17).
  11. Using DVOM, check voltage between ground and A/C pressure sensor circuit at PCM connector A-36 harness terminal B9 (Green wire). If no voltage exists, go to step 13). If voltage does exist, go to step 18).
  12. Disconnect EGR valve. Using DVOM, check voltage between ground and EGR pintle position sensor signal circuit at PCM connector A-36 harness terminal B7 (Yellow/Red wire). If no voltage exists, go to next step. If voltage exists, go to step 19).
  13. Replace EGR valve. Verify system is operating properly.
  14. Repair short to voltage in Gray wire between PCM connector A-38 and MAP sensor.
  15. Repair short to voltage in Blue wire between PCM connector A-38 and TP sensor.
  16. Repair short to voltage in Yellow/Green wire between PCM connector A-36 and IAT sensor.
  17. Repair short to voltage in Blue/Red wire between PCM connector A-38 and ECT sensor.
  18. Repair short to voltage in Green wire between PCM connector A-36 and A/C pressure sensor.
  19. Repair short to voltage in Yellow/Red wire between PCM connector A-36 and EGR valve.
  20. Replace PCM. Program PCM. Repeat OBD-II system check.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Attempt to start engine. If engine does not start, go to step 6). If engine starts, go to next step.
  3. Check METER fuse CB-7 (15-amp) located in dash fuse box. If fuse is okay, go to next step. If fuse is blown, go to step 16).
  4. Turn ignition on. Using test light connected to ground, probe ignition feed circuit at instrument cluster terminal No. 14 (Yellow wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 13).
  5. Turn ignition off. Disconnect PCM harness connector A-36. Connect a jumper wire between ground and MIL control circuit at PCM connector A-36 terminal A13 (White/Green wire). Turn ignition on. If MIL comes on, go to step 10). If MIL does not come on, go to step 11).
  6. Check ENGINE DEVICE fuse CB-3 (15-amp) located in dash fuse box. Check PCM fuse EB-12 (15-amp) in fuse/relay box located in engine compartment. If fuses are okay, go to next step. If fuses are blown, go to step 15).
  7. Turn ignition off. Disconnect PCM harness connector A-38. Turn ignition on. Using test light connected to ground, probe ignition feed circuits at PCM harness connector A-38 terminal E16 and F16 (Red/Blue wires). If test light illuminates, go to next step. If test light does not illuminate, go to step 12).
  8. Using test light connected to ground, probe battery feed circuit at PCM connector A-36 terminal A4 (Red/White wire). If test light illuminates, go to next step. If the test light does not illuminate, go to step 14).
  9. Check for faulty PCM ground connections. Repair as necessary. If connections are okay, go to next step.
  10. Check PCM harness connectors for damaged terminals. If any terminals are damaged, replace PCM. If PCM harness connector terminals are okay, go to step 17).
  11. Check for an open in MIL control circuit (White/Green wire) between PCM and MIL. Repair as necessary. If circuit is okay, go to step 18).
  12. Substitute PCM main relay with a known-good relay. PCM main relay is located in fuse/relay box in engine compartment. Observe MIL. If MIL operates properly, replace PCM main relay. If MIL still does not operate, go to next step.
  13. Repair open in ignition feed circuit (Black/Yellow wire) between PCM main relay and dash fuse box.
  14. Repair open in PCM battery feed circuit (Red/White wire) between PCM and fuse/relay box located in engine compartment.
  15. Repair short to ground in PCM ignition feed circuit (Black/Yellow wire) or PCM battery feed circuit (Red/White wire). See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. Replace fuse.
  16. Repair the short to ground in ignition feed circuit (Yellow wire) between instrument cluster and dash fuse box. Replace fuse.
  17. Replace PCM. Program PCM. Verify proper system operation.
  18. Check MIL driver circuit (White/Green wire) for poor connection at instrument cluster connector. Repair as necessary. If no problem is found, diagnose problem in instrument cluster. See «INSTRUMENT PANELS»(ref-26406) article in ACCESSORIES/SAFETY EQUIP section.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM harness connector A-36. Turn ignition on. If MIL comes on, go to next step. If MIL does not come on, go to step 5).
  3. Turn ignition off. Disconnect instrument panel cluster connector. Check for short to ground in MIL control circuit (White/Green wire) between PCM harness connector A-36 terminal A13 and instrument panel cluster. Repair as necessary. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. If circuit is okay, go to next step.
  4. Replace instrument panel cluster. See «INSTRUMENT PANELS»(ref-26406) article in ACCESSORIES/SAFETY EQUIP section. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES -INTRODUCTION»(ref-16364) article.
  5. Turn ignition off. Reconnect PCM harness connector A-36. Turn ignition on. Reprogram EEPROM. Using scan tool, command MIL OFF. If MIL did not go off, go to next step. If MIL did go off, repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  6. Replace PCM. Program PCM. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
WARNINGRelieve fuel pressure before connecting fuel pressure gauge. See FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEM.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Check IGNITION COIL fuse CB-4 (15-amp) and ENGINE DEVICE fuse CB-3 (15-amp) located in dash fuse box. Check PCM fuse EB-12 (15-amp) located in fuse/relay box in engine compartment. If any fuse is blown, go to next step. If fuses are okay, go to step 4).
  3. Check for short to ground in appropriate circuits. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. Repair as necessary. Replace any blown fuses.
  4. Turn ignition off. Install fuel pressure gauge to fuel supply line test fitting. Turn ignition on. If fuel pressure is 43-55 psi (2.9-3.9 kg/cm 2 ) and holds steady, go to step 6). If fuel pressure is not 43-55 psi (2.9-3.9 kg/cm 2 ) or does not hold steady, go to next step.
  5. If no fuel pressure is indicated, go to «FUEL SYSTEM DIAGNOSIS»(ref-16362-S09176513662001010800000) . If any fuel pressure is indicated, go to «FUEL SYSTEM ELECTRICAL TEST»(ref-16362-S25147947672001010800000) .
  6. Install Injector Tester (J-39021-2 ) at injector test connector and activate fuel injector. If fuel pressure drops, go to next step. If fuel pressure does not drop, go to step 18).
  7. Install fuel injector test light (noid light) at cylinder No. 2 injector harness connector. Turn ignition on and crank engine. If noid light blinks, go to next step. If light does not blink, go to step 24).
  8. Turn ignition off. Disconnect 6-pin Ignition Control Module (ICM) harness connector at ignition coil. Using a test light connected to battery voltage, probe each terminal of 6-pin harness connector while cranking engine. If test light flashes at each terminal, go to step 12). If test light does not flash at each terminal, go to next step.
  9. Remove 5-pin ICM harness connector from ignition coil. Turn ignition on. Using a test light, verify module is being supplied with battery voltage at 5-pin ICM harness connector terminal No. 2 (Black/Yellow wire). Using a self-powered test light connected to ground, probe 5-pin ICM harness connector terminal No. 1 (Black wire). If test light does not illuminate at both terminals, go to next step. If test light illuminates at both terminals, go to step 11).
  10. Repair open in Black/Yellow wire between ICM and dash fuse box, or in Black wire between ICM and ground.
  11. Repair or replace ICM as necessary.
  12. Reconnect 6-pin ICM harness connector. Remove electrical connector from each ignition coil. Using a test light connected to battery voltage, probe each ignition coil terminal No. 2 (Green or Green with tracer wire) of coil connector. While cranking engine, observe test light. If test light does not flash at each coil connector, go to next step. If test light flashes at each coil connector, go to step 14).
  13. Repair open in appropriate circuit between coil connector and ICM connector.
  14. Turn ignition on. Ensure all coil connectors are disconnected. Using a test light connected to ground, probe ignition feed circuit to each ignition coil connector terminal No. 3 (Black/Orange wire). If test light does not illuminate at each terminal, go to next step. If test light illuminates at each terminal, go to step 16).
  15. Repair open in Black/Orange wire between appropriate ignition coil and dash fuse box.
  16. Ensure all coil connectors are disconnected. Using a test light connected to battery voltage, probe secondary ground circuit to each ignition coil connector terminal No. 1 (Black wire). If test light does not illuminate at each terminal, go to next step. If test light illuminates at each terminal, go to step 18).
  17. Repair open in Black wire between appropriate ignition coil and ground.
  18. Test for fuel contamination. If fuel is not contaminated, go to next step. If fuel is contaminated, clean fuel system as necessary. Replace fuel filter and verify all fuel injectors are delivering fuel.
  19. Remove any ignition coil. Install spark tester at spark plug end of coil. While cranking engine, check ignition coil for crisp Blue spark. If poor spark or no spark is found, go to next step. If spark is okay, go to step 21).
  20. Replace faulty ignition coil. Repeat test from previous step for each ignition coil. Replace as necessary. Verify system is operating properly.
  21. Repeat test from step 19) for each ignition coil. Test one coil at a time, and reinstall each coil on its spark plug when testing is complete ( DO NOT install screws). Start engine. If engine does not start, go to next step. If engine starts, install ignition coil screws and verify system is operating properly.
  22. Remove all spark plugs. Inspect spark plugs for fouling, loose or missing electrodes, or cracked plugs. Clean or replace spark plugs as necessary. If spark plugs are okay, go to next step.
  23. Check for these possible conditions: Faulty or incorrect camshaft belt. Incorrect valve timing. Leaking or sticking valves or rings. Leaking head gasket. Excessive valve deposits. Loose or worn rocker arms. Weak valve springs. If problem is found, repair as necessary. See appropriate article in ENGINES section. If no problem is found, go to step 25).
  24. Using scan tool, select ENGINE SPEED display. While cranking engine, observe scan tool. If RPM is indicated on scan tool, go to next step. If engine RPM is not indicated, go to step 34). NOTE: If scan tool is powered by cigarette lighter socket and display goes blank while cranking engine, it will be necessary to power scan tool directly from battery.
  25. Disconnect 7-pin, Gray connector E-9 at rear of air cleaner (below where air duct attaches to MAF sensor). Turn ignition on. Using a test light connected to ground, probe ignition feed circuit at female side of connector E-9 terminal No. 1 (Red/Blue wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 32).
  26. Connect test light between female side of connector E-9 terminal No. 1 (Red/Blue wire) and each specified terminal. See «CONNECTOR E-9 TERMINAL/PIN IDENTIFICATION»(ref-16362-S32709520802001010800000) . Turn ignition on. If test light illuminates at any terminal, go to next step. If test light does not illuminate at any terminal, go to step 29). CONNECTOR E-9 TERMINAL/PIN IDENTIFICATION Application Terminal No. Wire Color Injector No. 1 6 Green/White Injector No. 2 5 Green/Orange Injector No. 3 3 (1) Green Injector No. 4 2 Green/Red Injector No. 5 7 Green/Black Injector No. 6 4 Green/Yellow (1) Wire color may be White/Green.
  27. Turn ignition off. Disconnect PCM A-38 connector. Turn ignition on. If test light illuminates, go to next step. If test light does not illuminate, go to step 33).
  28. Repair short to ground in appropriate injector driver circuit. See «CONNECTOR E-9 TERMINAL/PIN IDENTIFICATION»(ref-16362-S32709520802001010800000) .
  29. Connect test light between female side of connector E-9 terminal No. 1 (Red/Blue wire) and each specified terminal. See «CONNECTOR E-9 TERMINAL/PIN IDENTIFICATION»(ref-16362-S32709520802001010800000) . Crank engine. If test light flashes at all terminals, go to step 31). If test light does not flash at all terminals, go to next step.
  30. Check for open in appropriate injector driver circuit. See «CONNECTOR E-9 TERMINAL/PIN IDENTIFICATION»(ref-16362-S32709520802001010800000) . Repair as necessary. If circuit is okay, go to step 33).
  31. Turn ignition off. Connect ohmmeter between male side of connector E-9 terminal No. 1 (Red/Blue wire) and each specified terminal. See «CONNECTOR E-9 TERMINAL/PIN IDENTIFICATION»(ref-16362-S32709520802001010800000) . If resistance is about 12.5 ohms at all pins, go to step 8). If resistance is not about 12.5 ohms at all pins, check for an open, shorted or faulty injector. Repair or replace as necessary.
  32. Repair Red/Blue wire(s) between PCM harness connector A-38, PCM main relay (located in fuse/relay box in engine compartment) and harness connector E-9.
  33. Replace PCM. Program PCM. Verify system is operating properly.
  34. Raise and support vehicle. Disconnect Crankshaft Position (CKP) sensor connector. Turn ignition on. Using a test light connected to ground, probe ignition feed circuit at CKP sensor harness terminal No. 1 (Yellow/Red wire). If test light does not illuminate, go to next step. If test light illuminates, go to step 36).
  35. Repair open or short to ground in Brown wire (Green wire after splice) between CKP sensor and PCM harness connector A-38.
  36. Turn ignition on. Connect a test light between CKP sensor harness terminals No. 1 (Brown wire; Green wire after splice) and No. 3 (Green wire). If test light illuminates, go to step 38). If test light does not illuminate, go to next step.
  37. Repair open or short to voltage in Green wire between CKP sensor and ground.
  38. Check for open or short in signal circuit (Yellow wire) between CKP sensor and PCM harness connector A-37. Repair as necessary. If circuit is okay, go to next step.
  39. Replace CKP sensor. Verify system is operating properly. If system is still not operating properly, go to step 33).
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM electrical connectors. Turn ignition on. Check for poor connections, open or short in 5-volt reference circuit for affected sensors. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. If problem is found, go to next step. If circuits are okay, go to step 4).
  3. Repair as necessary. Verify system is operating properly.
  4. Check for poor connections or open in ground circuits of affected sensors. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. If problem is found, go to next step. If connections and circuits are okay, go to step 6).
  5. Repair as necessary. Verify system is operating properly.
  6. Using DVOM, check voltage between ground and EGR pintle position sensor signal circuit at PCM harness connector A-36 terminal B7 (Yellow/Red wire). If no voltage exists, go to next step. If voltage exists, go to step 11).
  7. Using DVOM, check voltage between ground and MAP sensor signal circuit at PCM harness connector A-38 terminal F8 (Red wire). If no voltage exists, go to next step. If voltage exists, go to step 14).
  8. Using DVOM, check voltage between ground and TP sensor signal circuit at PCM harness connector A-38 terminal E8 (Blue wire). If no voltage exists, go to next step. If voltage exists, go to step 15).
  9. Using DVOM, check voltage between ground and IAT sensor signal circuit at PCM harness connector A-36 terminal B8 (Yellow/Green wire). If voltage is not present, go to next step. If voltage is present, go to step 16).
  10. Using DVOM, check voltage between ground and ECT sensor signal circuit at PCM harness connector A-38 terminal E9 (Blue/Red wire). If voltage is not present, go to next step. If voltage is present, go to step 17).
  11. Disconnect EGR valve. Using DVOM, check voltage between ground and EGR pintle position sensor signal circuit at PCM harness connector A-36 terminal B7 (Yellow/Red wire). If no voltage exists, go to step 14). If voltage exists, go to step 18). NOTE: TFT sensor may also be referred to as an A/T oil temperature sensor.
  12. Using DVOM, check voltage between ground and TFT sensor signal circuit at PCM harness connector A-38 terminal F4 (Green/Red wire). If no voltage exists, go to step 20). If voltage exists, go to step 19).
  13. Replace EGR valve. Verify EGR system is operating properly. 14) Repair short to voltage in Red wire between PCM harness connector A-38 and MAP sensor.
  14. Repair short to voltage in Blue wire between PCM harness connector A-38 and TP sensor.
  15. Repair short to voltage in Yellow/Green wire between PCM harness connector A-36 and IAT sensor.
  16. Repair short to voltage in Blue/Red wire between PCM harness connector A-38 and ECT sensor.
  17. Repair short to voltage in Yellow/Red wire between PCM harness connector A-36 and EGR valve.
  18. Repair short to voltage in Green/Red wire between PCM harness connector A-38 and TFT sensor.
  19. Replace PCM. Program PCM. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition on with engine off. If Malfunction Indicator Light (MIL) illuminates, go to next step. If MIL does not illuminate, go to step 4).
  3. Check Orange and Pink wires for poor connections at PCM harness connector C1. Repair as necessary. After repairs, go to step 22). If connections are okay, go to step 5).
  4. Attempt to start engine. If engine starts, go to step 6). If engine does not start, go to step 7).
  5. Check for poor PCM ground connection on engine block or PCM connector ground terminals. Repair as necessary. After repairs, go to step 22).
  6. Turn ignition off. Disconnect PCM connectors. Turn ignition on. Using a test light connected to ground, probe MIL control circuit (Brown/White wire) at PCM harness connector C2. See «WIRING DIAGRAMS»(ref-16366) article. If MIL illuminates, go to step 8). If MIL does not illuminate, go to step 9).
  7. Check ignition feed fuse (15-amp) and battery feed fuse (20-amp). If fuses are okay, go to step 10). If fuses are blown, go to step 11).
  8. Check for poor battery feed (Orange wire) and ignition feed (Pink wire), or MIL control circuit (Brown/White wire) connections at PCM harness connectors. Repair as necessary. After repairs are complete, go to step 22). If circuits are okay, go to step 12).
  9. Using a test light connected to ground, probe MIL control circuit (Brown/White wire) at PCM connector C2. If test light illuminates, go to step 13). If test light does not illuminate, go to step 14).
  10. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Using a test light connected to ground, probe ignition feed circuit (Pink wire) at PCM harness connector C1 terminal No.19. See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to step 15). If test light does not illuminate, go to step 16).
  11. Check for short to ground in Pink or Orange wire(s) between PCM harness connector C1 and fuse block. Repair as necessary and replace fuse(s). After repairs, go to step 22).
  12. Replace PCM. Program PCM. After repairs, go to step 22).
  13. Repair short to voltage in MIL control circuit (Brown/White wire). After repairs, go to step 22).
  14. Check for open or poor connection in MIL control circuit (Brown/White wire). See «WIRING DIAGRAMS»(ref-16366) article. Repair as necessary. After repairs, go to step 22). If circuit is okay, go to step 17).
  15. Using a test light connected to ground, probe Pink wire at PCM connector C1. See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to step 18). If test light does not illuminate, go to step 19).
  16. Repair open in battery feed circuit (Orange wire). After repairs, go to step 22).
  17. Check for open in Pink wire or blown fuse No. 19 between fuse block and MIL in instrument cluster. See «WIRING DIAGRAMS»(ref-16366) article. Repair as necessary. After repairs, go to step 22). If circuit or fuse is okay, go to step 20).
  18. Check for poor connections at battery feed circuit (Orange wire) or ignition feed circuit (Pink wire). Repair as necessary. After repairs, go to step 22). If circuits are okay, go to step 21).
  19. Repair open in Pink wire. After repairs, go to step 22).
  20. Replace Instrument Panel Cluster (IPC). After IPC replacement, go to step 22).
  21. Check for poor PCM ground connection on engine block or PCM connector. Repair as necessary. After repairs, go to next step. If connection and connector are okay, go to step 12).
  22. Warm engine to operating temperature. Check for DTCs. If DTCs are present, go to appropriate «TESTS W/CODES»(ref-16364) article. If DTC(s) do not exist, system is okay.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition on with engine off. MIL should illuminate. If MIL does not illuminate, go to «MALFUNCTION INDICATOR LIGHT (MIL) INOPERATIVE»(ref-16362-S36564639052001010800000) . If MIL illuminates, go to next step.
  3. Install Tech 2 scan tool. Using scan tool, command MIL on and off. If MIL turns on and off when commanded, go to step 8). If MIL does not turn on and off when commanded, go to next step.
  4. Turn ignition off. Disconnect PCM connectors. Turn ignition on. If MIL does not illuminate, go to step 7). If MIL illuminates, go to next step.
  5. Check for short to ground in MIL control circuit (Brown/White wire) between instrument cluster and PCM. See «WIRING DIAGRAMS»(ref-16366) article. Repair Brown/White as necessary. After repairs, go to step 8). If circuit is okay, go to next step.
  6. Replace Instrument Panel Cluster (IPC). After IPC replacement, go to step 8).
  7. Replace PCM. Program PCM. After repairs, go to next step.
  8. Using scan tool, clear DTC(s). Attempt to start engine. If engine starts and runs, go to next step. If engine does not start, or starts and dies, go to step 1).
  9. Warm engine to operating temperature. Check for DTCs. If DTCs are present, go to «TESTS W/CODES - INTRODUCTION»(ref-16364) article. If DTC(s) are not present, system is okay.

ENGINE CRANKS BUT WILL NOT START

Note. Before performing following tests, check battery condition, engine cranking speed and fuel supply.

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Check for Diagnostic Trouble Codes (DTCs). If DTC P0601, P0602 or P1621 exists, diagnose DTC(s). See appropriate «TESTS W/CODES - INTRODUCTION»(ref-16364) article. If DTC(s) do not exist, go to next step.
  3. Check PCM ground connection (Black/White wire) at engine block. Repair as necessary. After repairs, go to next step. If ground connection is okay, go to step 5).
  4. Check fuel pump and injector feed fuse ECM B (20-amp). If fuse is okay, go to step 6). If fuse is blown, go to step 7).
  5. Repair faulty PCM ground connection at engine block. After repairs, go to step 42).
  6. Check fuel level in tank and add fuel if necessary. If fuel level is okay, go to step 8). If fuel level was low and fuel needed to be added, go to step 41).
  7. Check for short to ground in fuel pump and injector feed circuit (Gray wire). Repair as necessary. Replace defective ECM B fuse (20-amp). After repairs, go to step 41).
  8. Install scan tool. Turn ignition on, with engine off. Ensure throttle is closed. Scan TP sensor. TP sensor value should be less than one volt. If TP sensor value is as specified, go to next step. If TP sensor value is not as specified, diagnose problem using DTC P0123. See «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  9. Using scan tool, monitor Engine Coolant Temperature (ECT) sensor and Intake Air Temperature (IAT) sensor values. Both values should be about the same. If values are about the same, go to next step. If values are not about the same, diagnose problem using DTC P0118. See «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  10. Check MAP sensor value with ignition on and engine cranking. If MAP sensor value is greater than 4 volts, then changes while cranking engine, go to next step. If MAP sensor value is less than 4 volts and does not change while cranking engine, go to step 12).
  11. Using scan tool, check Crankshaft Position (CKP) sensor activity while cranking engine. If CKP ACTIVITY COUNTER increments while cranking, go to step 14). If CKP ACTIVITY COUNTER does not increment, go to step 21).
  12. If serial data was lost while cranking engine, go to next step. If serial data was not lost while cranking engine, diagnose MAP sensor. See «I - SYSTEM & COMPONENT TESTS»(ref-16371) article.
  13. Repair voltage loss to PCM from ignition switch. Check for damaged harness or poor connections. After repairs, go to step 41).
  14. Install Spark Tester (J-26792) to cylinder No. 1, 2, 3 and 4 (one at a time). Connect the spark plug wire of companion cylinder to ground. Crank engine and observe spark tester. If spark exists, go to step 37). If spark does not exist, go to step 26).
  15. Turn ignition off. Disconnect 6-pin Ignition Control Module (ICM) connector. Using a DVOM, check resistance between ICM connector CKP sensor ground terminal (Black/White wire) and CKP sensor signal terminal (Purple wire). See «WIRING DIAGRAMS»(ref-16366) article. Resistance should be 700-1300 ohms. If resistance is as specified, go to step 17). If resistance is not as specified, go to next step.
  16. Remove CKP sensor. Ensure CKP sensor is still magnetized and terminals are not damaged. Using DVOM, check CKP resistance. Resistance should be 700-1300 ohms. If resistance is as specified, go to step 19). If resistance is not as specified, go to step 20).
  17. Set DVOM to AC scale. Connect DVOM between ICM connector CKP sensor ground terminal (Black/White wire) and CKP sensor signal terminal (Purple wire). See «WIRING DIAGRAMS»(ref-16366) article. Crank engine. Voltage reading should be greater than 200 millivolts (mV). If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 20).
  18. Connect test light to ICM 7x reference signal terminal (Purple/White wire). Touch remaining test light lead to ground and then to batter voltage. See «WIRING DIAGRAMS»(ref-16366) article. Monitor CKP ACTIVITY COUNTER increment on scan tool. If CKP ACTIVITY COUNTER increments as test light is touched to battery voltage, go to step 30). If CKP ACTIVITY COUNTER does not increment, go to step 24).
  19. Repair open or short in CKP sensor circuit (Purple wire). After repairs, go to step 41).
  20. Replace CKP sensor. After replacing CKP sensor, go to step 41).
  21. Turn ignition off. Disconnect 2-pin Ignition Control Module (ICM) connector. Turn ignition on. Using a test light, probe ICM connector ignition voltage terminal (Pink wire) and ground terminal (Black wire). See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to step 15). If test light does not illuminate, go to next step.
  22. Using a test light connected to ground, probe ICM connector ignition voltage terminal (Pink wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 25).
  23. Repair faulty ground circuit (Black/White wire) between ICM and ground. After repairs, go to step 41).
  24. Check CKP activity (7X reference) circuit (Red/Black wire) for an open or short. Repair circuit as necessary. After repairs are complete, go to step 41). If circuit is okay, go to step 31).
  25. Repair open in ICM power circuit (Pink wire). After repairs, go to step 41). NOTE: DO NOT leave jumper wire connected between IC circuit and battery voltage for more than 5 seconds.
  26. Turn ignition off. Disconnect PCM connectors. Connect spark tester to plug wire indicating no spark. Turn ignition on. Momentarily connect lead of fused jumper to battery power. Connect other lead of jumper wire to affected IC circuit. See «WIRING DIAGRAMS»(ref-16366) article. If spark jumps across spark tester, go to step 31). If spark does not jump across spark tester, go to step 32).
  27. Measure resistance of cable that would not produce spark with spark tester. If resistance is less than 30 k/ohms, go to next step. If resistance is greater than 30 k/ohms, go to step 35).
  28. Check secondary resistance of ignition coil that did not produce a spark. Resistance should be 5-8 k/ohms. If resistance is not as specified, go to step 36). If resistance is as specified, go to next step.
  29. Install a known-good ignition coil. Reconnect ICM connector. Install Spark Tester (J-26792) to faulty cylinder. Connect spark plug wire of companion cylinder to ground. Crank engine and observe spark tester. If spark is present, go to step 41). If spark is not present, go to next step.
  30. Replace ICM. After replacing ICM, go to step 41).
  31. Check for faulty PCM connector or connection. If connector and connection are okay, go to step 34). If connector and connection are faulty, go to step 33).
  32. Check ignition control circuit of faulty cylinder for an open or short. Repair circuit as necessary. See «WIRING DIAGRAMS»(ref-16366) article. After repairs, go to step 41). If circuit is okay, go to step 27).
  33. Repair faulty PCM connector or connection. After repairs, go to step 41).
  34. Replace PCM. Program PCM. After replacing PCM, go to step 41).
  35. Replace faulty spark plug wires. After repairs, go to step 41).
  36. Replace faulty ignition coil(s). After repairs, go to step 41).
  37. Disconnect all injector connectors. Connect injector test light to injector No. 1, 2, 3 and 4 (one at a time). Crank engine and observe injector test light. Test light should flash on all tests. If test light flashed, go to next step. If test light did not flash on all tests, or flashed only on one of the tests, or was on steady on one or all tests, go to step 40).
  38. Install fuel pressure gauge in fuel rail inlet line. Turn ignition on and note fuel pressure after 2 seconds. Fuel pressure should be 41-47 psi (2.9-3.3 kg/cm 2 ). If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, go to «FUEL SYSTEM»(ref-16362-S17690802422001010800000) .
  39. Check for fouled spark plugs. Replace as necessary. If spark plugs were fouled, go to step 41). If spark plugs were okay, check for water in fuel system. Check for basic engine mechanical problem (low compression). Ensure spark plugs are of resistor type. Check fuel pump operation with scan tool.
  40. Repair open in fuel pump and injector ignition feed circuit (Gray wire). After repairs, go to next step.
  41. Using scan tool, clear DTC(s). Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts but dies, go to step 2).
  42. Warm engine to operating temperature. Check for DTCs. If DTCs are present, go to appropriate «TESTS W/CODES - INTRODUCTION»(ref-16364) article. If DTC(s) are not present, system is okay.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Ensure fuel pump relay fuse ECM B (20-amp) is okay. If fuse is okay, go to next step. If fuse is faulty, go to step 20).
  3. Install Tech 2 scan tool. Turn ignition on. Using scan tool, command fuel pump on. Fuel pump should operate for about 2 seconds. If fuel pump operates as specified, diagnose fuel system. See «FUEL SYSTEM DIAGNOSIS»(ref-16362-S33383929702001010800000) . If fuel pump does not operate, go to next step.
  4. Remove fuel pump relay. Using a fused jumper wire, jumper fuel pump relay feed terminal (Dark Green/White wire) and fuel pump relay ignition feed terminal. See «WIRING DIAGRAMS»(ref-16366) article. If fuel pump operates, go to next step. If fuel pump does not operate, go to step 6).
  5. Using a test light connected to ground, probe fuel pump relay control terminal (Dark Green/white wire). See «WIRING DIAGRAMS»(ref-16366) article. Using scan tool, command fuel pump on. If test light illuminates, go to step 7). If test light does not illuminate, go to step 8).
  6. Using a test light connected to ground, probe fuel pump relay ignition feed terminal. See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to step 9). If test light does not illuminate, go to step 10).
  7. Using a test light connected to battery voltage, probe fuel pump relay ground terminal (Black wire). See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to step 11). If test light does not illuminate, go to step 12).
  8. Check for an open or short to ground in fuel pump relay control circuit (Dark Green/White wire). Repair as necessary. After repairs, go to step 25). If circuit is okay, go to step 13).
  9. Reinstall fuel pump relay. Disconnect fuel pump connector at fuel pump. Using a test light connected to ground, probe Gray wire at fuel pump connector feed terminal (body side). Using scan tool, command fuel pump on. If test light illuminates, go to step 14). If test light does not illuminate, go to step 15).
  10. Repair open in ignition feed circuit to fuel pump relay. See «WIRING DIAGRAMS»(ref-16366) article. After repairs, go to step 25).
  11. Replace fuel pump relay. After repairs, go to step 25).
  12. Repair open in fuel pump relay ground circuit (Black wire). After repairs, go to step 25).
  13. Check connections and terminals to PCM. Repair as necessary. After repairs, go to step 25). If connections and terminals are okay, go to step 16).
  14. Using a test light connected to battery voltage, probe Black wire at fuel pump terminal (body side). If test light glows, go to step 17). If test light does not glow, go to step 18).
  15. Repair open in fuel pump feed circuit (Gray wire). After repairs, go to step 25).
  16. Replace PCM. Program PCM. After replacing PCM, go to step 25).
  17. Check for an open in fuel pump feed circuit (Gray wire) and ground circuit (Black wire). Repair as necessary. After repairs, go to step 25). If circuit is okay, go to step 19).
  18. Repair open in fuel pump ground circuit (Black wire). After repairs, go to step 25).
  19. Replace fuel pump. After repairs, go to step 25).
  20. Disconnect fuel pump connector at fuel pump. Remove fuel pump relay. Turn ignition off. Using a test light connected to battery voltage, probe fuel pump feed terminal (Gray wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 22).
  21. Repair short to ground in fuel pump feed circuit (Gray wire). After repairs, go to step 25).
  22. Using a test light connected to battery voltage, probe fuel pump relay ignition feed terminal. See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to next step. If test light does not illuminate, go to step 24).
  23. Repair short to ground in fuel pump relay ignition feed circuit. See «WIRING DIAGRAMS»(ref-16366) article. After repairs, go to step 25).
  24. Check for short to ground in fuel pump feed circuit (Gray wire). Repair as necessary. After repairs, go to next step. If circuit is okay, go to step 19).
  25. Using scan tool, clear DTC(s). Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts but dies, go to step 2).
  26. Warm engine to operating temperature. Check for DTCs. If DTCs are present, go to appropriate «TESTS W/CODES - INTRODUCTION»(ref-16364) article. If DTC(s) are not present, system is okay.

Note. Vehicle Control Module (VCM) may also be referred to as Powertrain Control Module (PCM).

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn engine off for 15 seconds. Turn ignition on with engine off. If Malfunction Indicator Light (MIL) illuminates, go to step 6). If MIL does not illuminate, go to next step.
  3. Install Tech 2 scan tool. Turn ignition on with engine off. Using scan tool, attempt to communicate with VCM. If scan tool communicates with VCM, go to next step. If scan tool does not communicate with VCM, check wiring harness and connectors for damage, corrosion or loose connections. See «WIRING DIAGRAMS»(ref-16366) article. Repair as necessary and retest system.
  4. Turn ignition on. Using scan tool, command MIL to turn on and off. If MIL does not turn on and off as commanded, go to next step. If MIL turns on and off as commanded, go to step 23).
  5. Turn ignition off. Disconnect VCM Black harness connector. Turn ignition on. If Malfunction Indicator Light (MIL) illuminates, go to step 18). If MIL does not illuminate, go to step 19).
  6. Check for open in ignition and battery fuses. See «WIRING DIAGRAMS»(ref-16366) article. If fuses are okay, go to next step. If fuse(s) is open, go to step 20).
  7. Turn ignition off. Disconnect VCM Black and Clear harness connectors. Turn ignition on. Using a fused jumper connected to ground, probe VCM harness connector MIL control circuit (Brown/White wire). See «WIRING DIAGRAMS»(ref-16366) article. If MIL illuminates, go to next step. If MIL does not illuminate, go to step 12).
  8. Turn ignition off. Ensure VCM Black and Clear harness connectors are still disconnected. Turn ignition on. Using a test light connected to ground, probe VCM harness connector ignition feed circuit (Pink wire) and battery feed circuit (Orange wire). See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to next step. If test light does not illuminate, go to step 22).
  9. Using a test light connected to battery voltage. Probe VCM ground circuits (Black/White wires) at VCM connector. If test light does not illuminate, go to next step. If test light illuminates, go to step 19).
  10. Check for faulty VCM ground connection at engine block. If connections are okay, go to next step. If problem is found, repair as necessary. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  11. Repair open in VCM ground circuit. Black/White wire. After repairs, retest system.
  12. Check for open in fused jumper wire used in step 7). If fused jumper wire is okay, go to next step. If fused jumper is open, go to step 21).
  13. Check for open in MIL control circuit (Brown/White wire). See «WIRING DIAGRAMS»(ref-16366) article. If circuit is okay, go to next step. If open is found, repair as necessary. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  14. Check for open in Instrument Panel (IP) cluster connections. See «WIRING DIAGRAMS»(ref-16366) article. If circuit is okay, go to next step. If open is found, repair as necessary. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  15. Check MIL bulb. If no problem is found, go to next step. If faulty, replace bulb and perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES -INTRODUCTION»(ref-16364) article.
  16. Check for open in MIL circuit (Orange wire) between instrument panel and MIL. If no problem is found, go to next step. If problem is found, repair Orange wire as necessary. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  17. Replace faulty instrument cluster. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  18. Locate and repair short to ground in MIL control circuit (Brown/White wire). After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  19. Check VCM for faulty harness connections. If no problem was found, go to step 24). If problem was found, repair as necessary. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  20. Locate open(s) in ignition fuse circuit (Pink wire) and/or battery fuse circuit (Orange wire). See «WIRING DIAGRAMS»(ref-16366) article. Repair as necessary and replace fuse. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  21. Repair short to voltage in MIL control circuit (Brown/White wire). After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES -INTRODUCTION»(ref-16364) article.
  22. Locate and repair open(s) in VCM harness connector ignition feed circuit (Pink wire) and/or battery feed circuit (Orange wire). See «WIRING DIAGRAMS»(ref-16366) article. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  23. Ensure scan tool is properly connected. Turn ignition on. Using scan tool, command MIL to turn on and off. If MIL does not turn on and off as commanded, problem is intermittent. Check for damaged wiring harness, loose or corroded connections, damaged connectors and improper connector mating. Repair as necessary. After repair, perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  24. Replace VCM. Program VCM.

Note. Before performing following tests, check battery condition, engine cranking speed and fuel supply.

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Install Tech 2 scan tool. Using scan tool, monitor Throttle Position (TP) sensor. Ensure is throttle closed. If TP sensor value is greater than 2.5 volts, diagnose using DTC P0123. See appropriate «TESTS W/CODES - INTRODUCTION»(ref-16364) article. If TP sensor voltage is less than 2.5 volts, go to next step.
  3. Using scan tool, monitor Engine Coolant Temperature (ECT) sensor. If ECT sensor value is less than -22°F (-30°C), diagnose using DTC P0118. See appropriate «TESTS W/CODES - INTRODUCTION»(ref-16364) article. If ECT sensor is greater than specified, go to next step.
  4. Turn ignition off for 10 seconds. Turn ignition on. Fuel pump should operate for about 2 seconds. If fuel pump operates as specified, go to next step. If fuel pump does not operate as specified, go to FUEL SYSTEM.
  5. Turn ignition off. Disconnect injector harness connector at intake manifold. Using a test light connected to ground, probe injector feed circuit. See «WIRING DIAGRAMS»(ref-16366) article. Turn ignition on with engine off. If test light flashes, go to next step. If test light does not flash, go to step 8).
  6. Disconnect one spark plug wire. Install Spark Tester (J-26792). Crank engine. If spark is present, go to next step. If spark is not present, diagnose enhanced ignition system. See «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  7. Reconnect spark plug wire. Turn ignition off. Connect fuel pressure gauge. Turn ignition on with engine off. Observe fuel pressure. Fuel pressure should be 55-61 psi (3.9-4.3 kg/cm 2 ). If fuel pressure is as specified, perform fuel injector balance test. See INJECTOR BALANCE TEST under FUEL SYSTEM in «I - SYSTEM & COMPONENT TESTS»(ref-16371) article. If fuel pressure is not as specified, diagnose fuel system. See FUEL SYSTEM DIAGNOSIS.
  8. Repair injector ignition feed circuit. See «WIRING DIAGRAMS»(ref-16366) article. After repairs, go to next step.
  9. Using scan tool, select DTC, CLEAR INFO function. Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts and dies, go to step 2).
  10. Warm engine to normal operating temperature. Using scan tool, select DTC, FAILED THIS IGN function. If DTC(s) are displayed, diagnose DTC(s). See «TESTS W/CODES - INTRODUCTION»(ref-16364) article. If DTC(s) are not present, go to next step.
  11. Select CAPTURE INFO, REVIEW INFO function. If additional DTC(s) are displayed, diagnose DTC(s). See «TESTS W/CODES -INTRODUCTION»(ref-16364) article. If DTC(s) are not present, system is okay.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition off for about 10 seconds. Turn ignition on. Fuel pump should operate for about 2 seconds. If fuel pump operates as specified, go to IGNITION SYSTEM check. If fuel pump does not operate as specified, go to next step.
  3. Connect a fused jumper wire between battery positive and fuel pump test terminal. If fuel pump operates, go to next step. If fuel pump does not operate, go to step 12).
  4. Disconnect jumper wire from test terminal. Turn ignition off for 10 seconds. Turn ignition on. Fuel pump should operate for about 2 seconds. If fuel pump operates as specified, go to step 24). If fuel pump does not operate as specified, go to next step.
  5. Remove fuel pump relay. Turn ignition on with engine off. Using a test light connected to ground, probe fuel pump relay harness connector battery feed terminal (Orange wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 14).
  6. Connect test light between ground and fuel pump relay harness connector battery feed circuit (Orange wire). See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to next step. If test light does not illuminate, go to step 15).
  7. Connect test light between ground and fuel pump relay Gray wire terminal. Turn ignition off for 10 seconds. Turn ignition on. If test light illuminates for 2 seconds, then turns off, go to next step. If test light does not illuminate, go to step 16).
  8. Check for faulty fuel pump relay harness connector. Repair as necessary. After repair is complete, go to step 11). If connector is okay, go to next step.
  9. Replace fuel pump relay. After repair, go to next step.
  10. Start and warm engine to normal operating temperature. Ensure oil pressure is within normal range. Disconnect fuel pump relay. If engine continues to run, go to next step. If engine stalls/dies, go to step 17).
  11. Reinstall fuel pump relay. Turn ignition off. Using test light connected to ground, probe fuel pump test connector. If test light illuminates, go to step 18). If test light does not illuminate, go to step 24).
  12. Disconnect fuel pump harness connector. Using a fused jumper wire connected to battery voltage, jumper fuel pump test terminal. Using a test light connected to ground, probe fuel pump feed circuit (Gray wire). See «WIRING DIAGRAMS»(ref-16366) article. If test light illuminates, go to next step. If test light does not illuminate, go to step 20).
  13. Connect test light to fuel pump ground terminal (Black wire) on harness connector. If test light illuminates, go to step 19). If test light does not illuminate, go to step 21).
  14. Repair open in battery feed circuit (Orange wire) to fuel pump relay harness connector terminal. After repair, go to step 24).
  15. Repair open in fuel pump relay ground circuit (Black wire). After repair, go to step 24).
  16. Check for faulty connection at VCM connector fuel pump relay control circuit (Dark Green/White wire). Check for open or short to ground in harness between fuel pump relay control connector terminal and fuel pump relay control circuit (Dark Green/White wire). Repair as necessary. After repair is complete, go to step 22). If circuits are okay, go to step 23).
  17. Check for faulty oil pressure switch connector terminals. Repair as necessary. After repair, go to step 22). If connector terminals are okay, go to next step.
  18. Replace oil pressure switch. After repair, go to step 24).
  19. Replace fuel pump. After repair, go to step 24).
  20. Repair open between fuel pump test terminal and fuel pump feed circuit (Gray wire) at fuel pump harness connector. After repair, go to step 24).
  21. Repair open in fuel pump harness ground circuit (Black wire). After repair, go to step 24).
  22. Check for open or shorted oil pressure switch connector circuits. See «WIRING DIAGRAMS»(ref-16366) article. Repair affected circuit(s) as necessary. After repair(s), go to next step.
  23. Replace VCM. Program VCM. After repair, go to next step.
  24. Select CAPTURE INFO, REVIEW INFO function. If additional DTC(s) are displayed, diagnose DTC(s). See «TESTS W/CODES -INTRODUCTION»(ref-16364) article. If DTC(s) are not present, system is okay.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Attempt to start engine. If engine does not start, go to step 6). If engine starts, go to next step.
  3. Check METER fuse C-10 (10-amp) located in dash fuse box. If fuse is okay, go to next step. If fuse is blown, go to step 16).
  4. Turn ignition on. Using test light connected to ground, probe ignition feed circuit at instrument cluster terminal No. 14 (Blue/Yellow wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 13).
  5. Turn ignition off. Disconnect PCM C-1 electrical connector. Connect a jumper wire between ground and MIL control circuit at PCM connector C-1 terminal A13 (Purple wire). Turn ignition on. If MIL comes on, go to step 10). If MIL does not come on, go to step 11).
  6. Check ENGINE fuse C-8 (15-amp) located in dash fuse box. Check PCM fuse F-13 (30-amp) in fuse/relay box located in engine compartment. If fuses are okay, go to next step. If fuses are blown, go to step 15).
  7. Turn ignition off. Disconnect PCM C-3 electrical connector. Turn ignition on. Using test light connected to ground, probe ignition feed circuits at PCM connector C-3 terminal E16 and F16 (Red/Blue wires). If test light illuminates, go to next step. If test light does not illuminate, go to step 12).
  8. Using test light connected to ground, probe battery feed circuit at PCM connector C-1 terminal A4 (White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 14).
  9. Check for faulty PCM ground connections. Repair as necessary. If connections are okay, go to next step.
  10. Check PCM connectors for damaged terminals. If any terminals are damaged, repair terminals as necessary. Retest system. If PCM are okay, go to step 17).
  11. Check for an open in MIL control circuit (Purple wire) between PCM and MIL. Repair as necessary. If circuit is okay, go to step 18).
  12. Substitute PCM main relay with a known-good relay. PCM main relay is located in fuse/relay box in engine compartment. Observe MIL. If MIL operates properly, replace PCM main relay. If MIL still does not operate, go to next step.
  13. Repair open in ignition feed circuit (Black/Yellow wire) between PCM main relay and dash fuse box.
  14. Repair open in PCM battery feed circuit (Red/White wire) between PCM and fuse/relay box located in engine compartment.
  15. Repair short to ground in PCM ignition feed circuit (Black/Yellow or Red/Blue wire) or PCM battery feed circuit (Red/White wire). See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. Replace ENGINE fuse C-8 (15-amp).
  16. Repair the short to ground in ignition feed circuit (Blue/Yellow wire) between instrument cluster and dash fuse box. Replace fuse.
  17. Replace PCM. Reprogram PCM. Verify proper system operation.
  18. Check MIL driver circuit (Purple wire) for poor connection at instrument cluster connector. Repair as necessary. If no problem is found, diagnose problem in instrument cluster. See «INSTRUMENT PANELS»(ref-26406) article in ACCESSORIES/SAFETY EQUIP section.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM C-1 electrical connector. Turn ignition on. If MIL comes on, go to next step. If MIL does not come on, go to step 5).
  3. Turn ignition off. Disconnect instrument panel cluster connector. Check for short to ground in MIL control circuit (Purple wire) between PCM connector C-1 terminal A13 and instrument panel cluster. Repair as necessary. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES -INTRODUCTION»(ref-16364) article. If circuit is okay, go to next step.
  4. Replace instrument panel cluster. See «INSTRUMENT PANELS»(ref-26406) article in ACCESSORIES/SAFETY EQUIP section. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  5. Turn ignition off. Reconnect PCM C-1 electrical connector. Turn ignition on. Reprogram EEPROM. Using Tech 2 scan tool, command MIL OFF. If MIL did not go off, go to next step. If MIL did go off, repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
  6. Replace PCM. Program PCM. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.
WARNINGRelieve fuel pressure before connecting fuel pressure gauge. See FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEM.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Check IGNITION COIL fuse C-9 (15-amp) and ENGINE fuse C-8 (15-amp) located in dash fuse box. Check PCM fuse F-13 (30-amp) located in fuse/relay box in engine compartment. If any fuse is blown, go to next step. If fuses are okay, go to step 4).
  3. Check for short to ground in appropriate circuits. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. Repair as necessary. Replace any blown fuses.
  4. Turn ignition off. Relieve fuel system pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-16362-S34788331672001010800000) under FUEL SYSTEM. Install fuel pressure gauge to fuel supply line test fitting. Turn ignition on. If fuel pressure is 43-55 psi (2.9-3.9 kg/cm 2 ) and holds steady, go to step 6). If fuel pressure is not 43-55 psi (2.9-3.9 kg/cm 2 ) or does not hold steady, go to next step.
  5. If no fuel pressure is indicated, go to «FUEL SYSTEM DIAGNOSIS»(ref-16362-S33383929702001010800000) . If any fuel pressure is indicated, go to «FUEL SYSTEM ELECTRICAL TEST»(ref-16362-S06945948212001010800000) .
  6. Install Injector Tester (J-39021 ) at cylinder No. 2, and activate fuel injector. If fuel pressure drops, go to next step. If fuel pressure does not drop, go to step 14).
  7. Install fuel injector test light at cylinder No. 2 injector harness connector. Turn ignition on and crank engine. If noid light blinks, go to next step. If light does not blink, go to step 20).
  8. Remove 6-pin ignition coil module connector. Using a test light connected to battery voltage, probe each exposed ignition coil module terminal in sequence. While cranking engine, observe test light. If test light does not flash at each coil terminal, go to next step. If test light flashes at each coil terminal, go to step 10).
  9. Repair open in appropriate circuit between coil connector and PCM.
  10. Turn ignition on. Ensure all coil connectors are disconnected. Using a test light connected to ground, probe ignition feed circuit to each ignition coil connector terminal No. 2 (Black/Orange wire). If test light does not illuminate at each terminal, go to next step. If test light illuminates at each terminal, go to step 14).
  11. Repair open in Black/Orange wire between appropriate ignition coil and dash fuse box.
  12. Ensure all coil connectors are disconnected. Using a test light connected to battery voltage, probe secondary ground circuit to each ignition coil connector terminal No. 1 (Black wire). If test light does not illuminate at each terminal, go to next step. If test light illuminates at each terminal, go to step 14).
  13. Repair open in Black wire between appropriate ignition coil and ground.
  14. Test for fuel contamination. If fuel is not contaminated, go to next step. If fuel is contaminated, clean fuel system as necessary. Replace fuel filter and verify all fuel injectors are delivering fuel.
  15. Remove any ignition coil. Install spark tester at spark plug end of coil. While cranking engine, check ignition coil for crisp blue spark. If spark is okay, go to step 17). If weak spark or no spark exists, go to next step.
  16. Replace faulty ignition coil. Verify system is operating properly.
  17. Repeat test from step 15) for each ignition coil. Test one coil at a time, and reinstall each coil on its spark plug when testing is complete ( DO NOT install screws). Start engine. If engine does not start, go to next step. If engine starts, install ignition coil screws and verify system is operating properly.
  18. Remove all spark plugs. Inspect spark plugs for fouling, loose or missing electrodes, or cracked plugs. Clean or replace spark plugs as necessary. If spark plugs are okay, go to next step.
  19. Check for these possible conditions: Faulty or incorrect camshaft belt. Incorrect valve timing. Leaking or sticking valves or rings. Leaking head gasket. Excessive valve deposits. Loose or worn rocker arms. Weak valve springs. If problem is found, repair as necessary. See appropriate article in ENGINES section. If no problem is found, go to step 21).
  20. Using Tech 2 scan tool, select ENGINE SPEED display. While cranking engine, observe scan tool. If RPM is indicated on scan tool, go to next step. If engine RPM is not indicated, go to step 30). NOTE: If scan tool is powered by cigarette lighter socket and display goes blank while cranking engine, it will be necessary to power scan tool directly from battery.
  21. Disconnect Gray, 7-pin H-4 connector at rear of air cleaner (below where air duct attaches to MAF sensor). Turn ignition on. Using a test light connected to ground, probe ignition feed circuit at female side of connector H-4 terminal No. 1 (Red/Blue wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 28).
  22. Connect test light between female side of H-4 connector terminal No. 1 (Red/Blue wire) and each specified terminal. See «CONNECTOR H-4 TERMINAL/PIN IDENTIFICATION»(ref-16362-S26840068012001010800000) . Turn ignition on. If test light illuminates at any terminal, go to next step. If test light does not illuminate at any terminal, go to step 25). CONNECTOR H-4 TERMINAL/PIN IDENTIFICATION Application Terminal No. Wire Color Injector No. 1 6 Green/White Injector No. 2 5 Green/Orange Injector No. 3 3 Green Injector No. 4 2 Green/Red Injector No. 5 7 Green/Black Injector No. 6 4 Green/Yellow
  23. Turn ignition off. Disconnect PCM C-3 electrical connector. Turn ignition on. If test light illuminates, go to next step. If test light does not illuminate, go to step 29).
  24. Repair short to ground in appropriate injector driver circuit. See «CONNECTOR H-4 TERMINAL/PIN IDENTIFICATION»(ref-16362-S26840068012001010800000) .
  25. Connect test light between female side of H-4 connector terminal No. 1 (Red/Blue wire) and each specified terminal. See «CONNECTOR H-4 TERMINAL/PIN IDENTIFICATION»(ref-16362-S26840068012001010800000) . Crank engine. If test light flashes at all terminals, go to step 27). If test light does not flash at all terminals, go to next step.
  26. Check for open in appropriate injector driver circuit. See «CONNECTOR H-4 TERMINAL/PIN IDENTIFICATION»(ref-16362-S26840068012001010800000) . Repair as necessary. If circuit is okay, go to step 29).
  27. Turn ignition off. Connect ohmmeter between male side of H-4 connector pin No. 1 (Red/Blue wire) and each specified pin. See «CONNECTOR H-4 TERMINAL/PIN IDENTIFICATION»(ref-16362-S26840068012001010800000) . If resistance is about 12.5 ohms at all pins, go to step 8). If resistance is not about 12.5 ohms at all pins, check for an open, shorted or faulty injector. Repair or replace as necessary.
  28. Repair Red/Blue wire(s) between PCM connector C-3, PCM main relay (located in fuse/relay box in engine compartment) and H-4 connector.
  29. Replace PCM. Program PCM. Verify system is operating properly.
  30. Raise and support vehicle. Disconnect Crankshaft Position (CKP) sensor connector. Turn ignition on. Using a test light connected to ground, probe ignition feed circuit at CKP sensor harness terminal No. 1 (Yellow/Red wire). If test light illuminates, go to step 32). If test light does not illuminate, go to next step.
  31. Repair open or short to ground in Yellow/Red wire between CKP sensor and PCM connector C-3.
  32. Turn ignition on. Connect test light between CKP sensor harness connector terminals No. 1 (Yellow/Red wire) and No. 3 (Yellow wire). If test light illuminates, go to step 34). If test light does not illuminate, go to next step.
  33. Repair open or short to voltage in Yellow/Red or Green wire between CKP sensor and ground.
  34. Check for open or short in signal circuit (Yellow wire) between CKP sensor and PCM connector C-2. Repair as necessary. If circuit is okay, go to next step.
  35. Replace CKP sensor. Verify system is operating properly. If system is still not operating properly, go to step 29).
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article. After performing OBD-II system check, go to next step.
  2. Turn ignition off. Disconnect PCM electrical connectors. Turn ignition on. Check for poor connections, open or short in 5-volt reference circuit for affected sensors. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. If problem is found, go to next step. If circuits are okay, go to step 4).
  3. Repair as necessary. Verify system is operating properly.
  4. Check for poor connections or open in ground circuits of affected sensors. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16366) article. If problem is found, go to next step. If connections and circuits are okay, go to step 6).
  5. Repair as necessary. Verify system is operating properly.
  6. Using DVOM, check voltage between ground and EGR pintle position sensor signal circuit at PCM connector C-1 harness terminal B7 (Yellow/Red wire). If no voltage exists, go to next step. If voltage exists, go to step 12). 7) Using DVOM, check voltage between ground and MAP sensor signal circuit at PCM connector C-3 harness terminal F8 (Red wire). If no voltage exists, go to next step. If voltage exists, go to step 15).
  7. Using DVOM, check voltage between ground and TP sensor signal circuit at PCM connector C-3 harness terminal E8 (Blue wire). If no voltage exists, go to next step. If voltage exists, go to step 16).
  8. Using DVOM, check voltage between ground and IAT sensor signal circuit at PCM connector C-1 terminal B8 (Yellow/Green wire). If no voltage exists, go to next step. If voltage exists, go to step 17).
  9. Using DVOM, check voltage between ground and ECT sensor signal circuit at PCM connector C-3 terminal E9 (Blue/Red wire). If no voltage exists, go to step 12). If voltage exists, go to step 18).
  10. Disconnect EGR valve. Using DVOM, check voltage between ground and EGR pintle position sensor signal circuit at PCM connector C-1 terminal B7 (Yellow/Red wire). If no voltage exists, go to step 13). If voltage exists, go to step 18). NOTE: TFT sensor may also be referred to as A/T oil temperature sensor.
  11. Using DVOM, check voltage between ground and TFT sensor signal circuit at PCM connector C-3 harness terminal E4 (Purple/White wire). If no voltage is present, go to step 20). If voltage is present, go to step 19).
  12. Replace EGR valve. Verify system is operating properly.
  13. Repair short to voltage in Red wire between PCM connector C-3 and MAP sensor.
  14. Repair short to voltage in Blue wire between PCM connector C-3 and TP sensor.
  15. Repair short to voltage in Yellow/Green wire between PCM connector C-1 and IAT sensor.
  16. Repair short to voltage in Blue/Red wire between PCM connector C-3 and ECT sensor.
  17. Repair short to voltage in Yellow/Red wire between PCM connector C-1 and EGR valve.
  18. Repair short to voltage in Purple/White wire between PCM connector C-3 and TFT sensor.
  19. Replace PCM. Program PCM. Repeat OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in «TESTS W/CODES - INTRODUCTION»(ref-16364) article.

SUMMARY

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

More articles — Engine Controls - Basic Testing