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Ignition System

  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC (OBD-II) SYSTEM CHECK in TESTS W/CODES - INTRODUCTION 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 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 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 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 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 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 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 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 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 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 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/cm2 ). If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, go to FUEL SYSTEM  .
  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 article. If DTC(s) are not present, system is okay.
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