Engine Cranks But Does Not Run
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Circuit Description
The electronic Ignition System uses a coil-at-plug method of spark distribution. In this type of Ignition System, the Powertrain Control Module (PCM) triggers the correct driver inside the ignition control module (ICM), which then triggers the correct ignition coil based on the 58X signal received from the Crankshaft position sensor (CKP). The Spark Plug connected to the coil fires when the ICM opens the ground circuit for the coil's primary circuit.
During crank, the PCM monitors the CKP 58X signal. The CKP signal is used to determine which cylinder will fire first. After the CKP 58X signal has been processed by the PCM, it will command all six injectors to allow a priming shot of fuel for all the cylinders. After the priming, the injectors are left "OFF" during the next six 58X reference pulses from the CKP. This allows each cylinder a chance to use the fuel from the priming shot. During this waiting period, a camshaft position (CMP) signal pulse will have been received by the PCM. The CMP signal allows the PCM to operate the injectors sequentially based on camshaft position. If the camshaft position signal is not present at start-up, the PCM will begin sequential fuel delivery with a 1 - in - 6 chance that fuel delivery is correct. The Engine will run without a CMP signal, but will set a DTC code.
Diagnostic Aids
An intermittent problem may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the insulation. Check for the following items:
- Poor connection or damaged harness - Inspect the PCM harness and connectors for improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness.
- Faulty Engine coolant temperature (ECT) sensor - Using a Scan Tool, compare Engine coolant temperature with intake air temperature on a completely cool Engine. Engine coolant temperature should be within 10°C of intake air temperature. If not, replace the ECT sensor.
Test Description
Number(s) below refer to the step number(s) in the Diagnostic Test:
6. By using a spark tester, the ignition coil's ability to produce at least 25,000 volts is verified.
34. An obvious cause of low fuel pressure would be an empty fuel tank.
37. The injector test connector is a gray 5-way connector locates at the right rear of the valve cover. The injector test connector can be identified by the blue connector lock which is tethered to the wire harness. If any of the lights on test light J 39021-45 constantly illuminate or fail to blink when the Engine is cranked, there is a short or open circuit in the injector harness or a faulty PCM. A blinking test lamp verifies that the PCM. A blinking test lamp verifies that the PCM is monitoring the 58X Crankshaft reference signal and is capable of activating the injectors. If there is an open or shorted injector driver circuit, DTCs 201-204 should be set.
Diagnostic Test
1. Was the "On-Board Diagnostic (OBD) System Check" performed?
[YES] Go to Step 2.
[NO] Go to OBD System Check. Initial Inspection
2. a. Check the 15-A ignition coil fuse, the 15-A Engine device fuse, and the 15-A Engine Control Module (ECM) fuse.
b. Was a fuse blown?
[YES] Go to Step 3.
[NO] Go to Step 4.
3. a. Check for a short to ground and replace the fuse.
b. Is the action complete?
[YES] Verify repair.
4. a. Ignition "ON".
b. Use a grounded test lamp to verify that B+ is available at the ignition coil fuse, the Engine device fuse, and the ECM fuse.
c. Was B+ available at the fuses?
[YES] Go to Step 6.
[NO] Go to Step 5.
5. Repair the open ignition feed circuit.
[YES] Go to Fuel System Electrical Test. Fuel System Electrical Test
[NO] Go to Fuel System Diagnosis. Fuel System Diagnosis
6. a. Disconnect the ignition coil-to-distributor secondary wire at the distributor.
b. Install a spark tester J 26792 at the end of the disconnected secondary wire.
c. Clip the spark tester J 26792 to a good ground (not near the battery).
d. Observe the spark tester while the Engine is cranking.
e. Was a crisp blue spark observed? (Only one or two sparks followed by no result is considered the same as No Spark.")
[YES] Go to Step 23.
[NO] Go to Step 7.
7. a. Disconnect the ignition module harness connector.
b. Connect a test light to B+ and touch it to the blue wire at the ignition harness connector.
c. Observe the test light when the Engine is cranked.
d. Does the test light flash?
[YES] Go to Step 16.
[NO] Go to Step 8.
8. a. Disconnect the ignition module harness connector.
b. Check for an open or short circuit between the ignition control module and the tighten coil.
c. Was a problem found?
[YES] Go to Step 9.
[NO] Go to Step 10.
9. Repair the short or open circuit.
[YES] Verify repair.
10. a. Ignition "ON".
b. Use a DVM to check the ignition wire at the ignition module harness connector.
c. Was the voltage equal to the specified value?
[VALUES] B+
[YES] Go to Step 11.
[NO] Go to Step 12.
11. Repair the open circuit or faulty ECM main relay.
[YES] Verify repair.
12. a. Ignition "OFF".
b. With DVM, check the ground wire at the ignition module harness connector.
c. Was the ground wire OK?
[YES] Go to Step 13.
[NO] Go to Step 9.
13. Is there an open circuit between the ignition module and the PCM?
[YES] Go to Step 9.
[NO] Go to Step 14.
14. a. Replace the ignition module.
b. Is there still a problem?
[YES] Go to Step 15.
[NO] Verify repair.
15. a. Replace the PCM.
IMPORTANT: The replacement PCM must be programmed.
b. Is the action complete?
[YES] Verify repair.
16. a. Ignition coil harness disconnected from the ignition coil.
b. Connect a test light to ground, and touch the test lamp to the ORN/BLK wire at the ignition coil harness.
c. Ignition "ON".
d. Does the test lamp illuminate?
[YES] Go to Step 18.
[NO] Go to Step 17.
17. Repair the open circuit between the ignition coil fuse and the ignition coil.
[YES] Verify repair.
18. a. Use and ohmmeter to check the ignition coil primary resistance.
b. primary resistance approximately equal to the specified value?
[VALUES] 0.8 - 18.0 ohms.
[YES] Go to Step 20.
[NO] Go to Step 19.
19. Replace the Ignition Coil.
[YES] Verify repair.
20. a. Use an ohmmeter to check the Ignition Coil secondary resistance.
b. Was the secondary resistance equal to the specified value?
[VALUES] 9,000 - 12,000 ohms.
[YES] Go to Step 21.
[NO] Go to Step 19.
21. a. Test the resistance of the coil-to-distributor secondary ignition wire.
b. Was the resistance greater than the specified value?
[VALUES] 22.5 ohms.
[YES] Go to Step 22.
[NO] Go to Step 19.
22. a. Replace the coil-to-distributor secondary ignition wire and any other secondary wires which exceed the specified value.
b. Is there still a problem?
[VALUES] 22.5 ohms.
[YES] Go to Step 19.
[NO] Verify repair.
23. a. Reconnect the coil-to-distributor secondary wire.
b. Disconnect one of the secondary wires from a Spark Plug.
c. Attach the disconnected Spark Plug wires to the spark tester J 26792.
d. Observe the spark tester while the Engine is cranking.
e. Was a crisp blue spark observed? (Only one or two sparks followed by no result is considered the same as "No Spark.").
[YES] Go to Step 31.
[NO] Go to Step 24.
24. a. Remove the distributor cap.
b. Inspect the cap for cracks, carbon tracking, a damaged center contact, or their defects..
c. Was the distributor cap OK?
[YES] Go to Step 26.
[NO] Go to Step 25.
25. Replace the distributor cap.
[YES] Verify repair.
26. a. Examine the distributor rotor.
b. Did the rotor show signs of excessive wear or damage?
[YES] Go to Step 27.
[NO] Go to Step 28.
27. Replace the distributor rotor.
[YES] Verify repair.
28. a. Disconnect the primary wire harness connector from the ignition coil.
b. Observe the distributor rotor while the Engine is cranked.
c. Did the rotor turn when the Engine was cranked?
[YES] Go to Step 30.
29. Repair the broken or stripped camshaft timing belt or faulty distributor pinion gear.
[YES] Verify repair.
30. Test the secondary ignition wires with an ohmmeter, and replace any wires for which the resistance exceeds the specified value.
[VALUES] 22.5 ohms.
[YES] Verify repair.
31. a. Test the other 3 Spark Plug wires by using the test in Step 23 at each Spark Plug wire.
b. When the Engine is cranked, was a crisp blue spark observed? (Only one or two sparks followed by no result is considered the same as "No Spark.").
[YES] Go to Step 32.
[NO] Go to Step 24.
32. a. Remove the Spark Plugs from all cylinders.
b. Visually inspect the Spark Plug electrodes.
c. Replace any Spark Plugs with loose or missing electrodes or cracked insulators.
d. Did your inspection reveal any Spark Plugs exhibiting excessive fouling?
[YES] Correct the fouling condition.
[NO] Go to Step 33.
33. a. Ignition "OFF", install a fuel pressure gauge at the test fitting on the fuel supply line in the Engine compartment. (Use a shop cloth to absorb any fuel leakage while making the connection.)
b. Ignition "ON", observe the fuel pressure.
c. Is the fuel pressure within the specified values, and does it hold steady?
[VALUES] 285 - 375 kPa (43-55 psi).
[YES] Go to Step 35.
[NO] Go to Step 34.
34. Is any fuel pressure indicated?
[YES] Go to Fuel System Electrical Test. Fuel System Electrical Test
[NO] Go to Fuel System Diagnosis. Fuel System Diagnosis
35. a. Install switch box J 39021-2 and J 39021-90 at the injector test connector.
b. Activate an injector.
c. Did the fuel pressure drop when the injector was activated?
[YES] Go to Step 36.
[NO] Go to Fuel System Diagnosis. Fuel System Diagnosis
36. a. Pressurize the fuel system using the ignition "ON" and use the injector switch box to test pressure drop for each injector.
b. Was there a pressure drop when each injector was activated?
[YES] Go to Step 37.
[NO] Go to Fuel System Diagnosis. Fuel System Diagnosis
37. a. Remove the switch box and install an injector test light h 39021-45 at the injector test harness connector.
b. Crank the Engine.
c. Are any of the lights blinking when the Engine is cranked?
[YES] Go to Step 43.
[NO] Go to Step 38.
38. a. Raise the vehicle and disconnect the CKP sensor harness.
b. Ignition "ON."
c. With a test light to ground, probe the CKP ignition feed harness terminal.
d. Did the light illuminate?
[YES] Go to Step 9.
[NO] Go to Step 39.
39. a. Ignition "ON".
b. At the CKP harness connector, connect a test lamp between the ignition and ground terminals.
c. Did the lamp illuminate?
[YES] Go to Step 41.
[NO] Go to Step 40.
40. a. Check the signal circuit between the sensor and the PCM for a short or open.
b. Was a problem found?
[YES] Go to Step 41.
[NO] Go to Step 40.
41. a. Replace the CKP position sensor.
b. Is there still a problem?
[YES] Go to Step 9.
[NO] Go to Step 42.
42. a. Test the fuel for contamination.
b. If a problem is found, clean the fuel system and correct the contaminated fuel condition as necessary.
c. Replace the Fuel Filter and replace any injectors that are not delivering fuel (see Injector Balance Test).
d. Was a problem found?
[YES] Verify repair.
[NO] Go to Step 43.
43. a. Refer to Engine / System Diagnosis to diagnose the following conditions:
- Slipped camshaft drive belt.
- Leaking or sticky valves or rings.
- Excessive valve deposits.
- Loose or worn rocker arms.
- Weak valve springs.
- Leaking head gasket.
b. Is the action complete?
[YES] Verify repair.