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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Basic Diagnostic Procedures >> No-Start Diagnosis >> No-Start - Engine Cranks Okay (6.6L Diesel) >> Diagnostic Procedure

Diagnostic Procedure

  1. Perform OBD system check. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. After performing diagnostic system check, go to next step.
  2. Turn ignition on, with engine off. Check for DTCs. If DTC P0088, P0089, P0090, P0335, P0336, P0340, P0370, P0374, P0380, P0601, P0602, P0603, P0604, P0611, P0612, P1621, P1626, P1631, P1683, or U1800 is set, perform appropriate diagnostic procedure for DTC set. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. If no DTCs are set, go to next step.
  3. If customer's concern is with a fuel smell or fuel leak, go to FUEL LEAKS INSIDE OF ENGINE (6.6L) or FUEL LEAKS OUTSIDE OF ENGINE (6.6L) under FUEL SYSTEM (DIESEL) in SYSTEM & COMPONENT TESTING - TRUCKS - EXCEPT TRACKER article. If a fuel smell or fuel leak concern is not present, go to next step.
  4. Turn ignition on. Using scan tool, observe Actual Fuel Rail Pressure parameter. If pressure is 159-203 psi (1100-1400 kPa), go to next step. If pressure is not as specified, go to step  18.
  5. Using scan tool, observe Ignition 1 signal parameter. If Ignition 1 signal parameter indicates battery voltage, go to next step. If Ignition 1 signal parameter does not indicate battery voltage, go to step  24.
  6. Attempt to start engine. Using scan tool, observe Engine Speed parameter while cranking engine. If Engine Speed parameter is more than zero RPM, go to next step. If Engine Speed parameter is not more than zero RPM, go to step  19.
  7. Test CKP sensor signal and low reference circuits for high resistance. After repairs, go to step  34. If CKP sensor signal and low reference circuits are okay, go to next step.
  8. Check for excessive fuel in engine oil, contaminated fuel and check fuel specific gravity. After repairs, go to step  34. If engine oil, fuel and fuel specific gravity are okay, go to next step.
  9. Install vacuum gauge to fuel system service port on right front side of engine. Attempt to hand prime fuel manager 30 times or until fuel pressure is 8 psi (55 kPa). If fuel system is able to be primed to 8 psi (55 kPa), go to next step. If fuel system is not able to be primed to 8 psi (55 kPa), go to step  31.
  10. If system pressure is maintained at more than 2.0 psi (13.8 kPa) for more than 2 minutes, go to next step. If system is not able to maintain more than 2.0 psi (13.8 kPa) for more than 2 minutes, go to step  14.
  11. Check engine compression. For compression specifications, see SERVICE & ADJUSTMENT SPECIFICATIONS - TRUCKS article. Repair engine as necessary. After repairs, go to step  34. If engine compression is within specification, go to next step.
  12. If any cylinders emitted fuel vapor during engine compression test, go to step  28. If no fuel vapor was emitted from cylinders during engine compression test, go to next step.
  13. Crank engine for 15 seconds. Using scan tool, observe Actual Fuel Rail Pressure parameter. If Actual Fuel Rail Pressure parameter is more than 1450 psi (10 MPa), go to step  15. If Actual Fuel Rail Pressure parameter is 1450 psi (10 MPa) or less, go to next step.
  14. Reprime fuel manager to 10 psi. Attempt to start engine while prime is still above 8 psi (55 kPa). If engine now starts, go to FUEL SYSTEM DIAGNOSIS - PICKUP (6.6L) or FUEL SYSTEM DIAGNOSIS - CAB & CHASSIS (6.6L) under FUEL SYSTEM (DIESEL) in SYSTEM & COMPONENT TESTING - TRUCKS - EXCEPT TRACKER article. If engine does not start, go to FUEL SYSTEM DIAGNOSIS - HIGH PRESSURE SIDE under FUEL SYSTEM (DIESEL) in SYSTEM & COMPONENT TESTING - TRUCKS - EXCEPT TRACKER article.
  15. Using scan tool, observe Glow Plug System Type parameter. If Glow Plug System Type indicates Federal, go to next step. If Glow Plug System Type does not indicate Federal, go to step  17.
    16. NOTE: Repeat this procedure on both cylinder banks. This test may be repeated as many times as necessary.
  16. Turn ignition off. Connect a test light to a glow plug harness connector on one side of engine. Turn ignition on, with engine off. If test light illuminates and then goes off, go to next step. If test light does not illuminate and then go off, go to GLOW PLUG SYSTEM DIAGNOSIS under FUEL SYSTEM (DIESEL) in SYSTEM & COMPONENT TESTING - TRUCKS - EXCEPT TRACKER article.
  17. Check for the following conditions:
    • Plugged air filter.
    • Collapsed air intake duct.
    • Inoperative fuel heater. If customer's concern is that engine will not start when ambient temperatures are less than 35-40°F (2-4°C), go to FUEL HEATER INOPERATIVE DIAGNOSIS (6.6L) under FUEL SYSTEM (DIESEL) in SYSTEM & COMPONENT TESTING - TRUCKS - EXCEPT TRACKER article.
    • Restricted exhaust system.

    Repair as necessary. After repairs, go to step  34. If no repairs are necessary, go to DIAGNOSTIC AIDS .

  18. Disconnect fuel rail pressure sensor. Using scan tool, observe Actual Fuel Rail Pressure parameter on scan tool. If Actual Fuel Rail Pressure parameter is more than 25,381 psi (175 MPa), go to step  23. If Actual Fuel Rail Pressure parameter is 25,381 psi (175 MPa) or less, go to step  22.
  19. Turn ignition off. Disconnect Crankshaft Position (CKP) sensor. Turn ignition on, with engine off. Using a DVOM connected to ground, probe 12-volt reference circuit at CKP sensor. If voltage is more than 10 volts, go to step  29. If voltage is 10 volts or less, go to next step.
  20. Turn ignition off. Disconnect Camshaft Position (CMP) sensor. Turn ignition on, with engine off. Using a DVOM connected to ground, probe 12-volt reference circuit of CMP sensor. If voltage is more than 10 volts, go to step  30. If voltage is 10 volts or less, go to next step.
  21. Check 12-volt reference circuit to CKP sensor and CMP sensor for a short to ground. Repair as necessary. After repairs, go to step  34. If no repairs are necessary, go to step  33.
  22. Check fuel rail pressure sensor signal circuit for a short to ground. Repair as necessary. After repairs, go to step  34. If no repairs are necessary, go to step  33.
  23. Check fuel rail pressure sensor circuits for high resistance. Repair as necessary. After repairs, go to step  34. If no repairs are necessary, go to step  25.
  24. Check Ignition 1 voltage circuit of ECM for a short to ground, high resistance or an open. Repair as necessary. After repairs, go to step  34. If no repairs are necessary, go to step  26.
  25. Check for an intermittent or for a poor connection at fuel rail pressure sensor. Repair as necessary. After repairs, go to step  34. If no repairs are necessary, go to step  32.
  26. Clean and tighten ECM shared ground. Repair as necessary. After repairs, attempt to start engine. If engine starts, go to step  34. If engine does not start, go to next step.
  27. Check for an intermittent and for a poor connection at ECM. Repair as necessary. After repairs, go to step  34. If no repairs are necessary, go to step  33
    28. NOTE: When fuel injector pressure lines are removed, debris will fall on fuel injector inlet fitting. Remove debris from area to prevent debris from falling in fuel injector.
  28. Replace fuel injectors on affected cylinders. After repairs, go to step  34.
  29. Replace CKP sensor. After repairs, go to step  34.
  30. Replace CMP sensor. After repairs, go to step  34.
  31. Replace fuel filter/heater element housing. After repairs, go to step  34.
  32. Replace fuel rail pressure sensor. After repairs, go to step  34.
  33. Replace ECM. Perform ECM relearn procedures. See PROGRAMMING in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. After repairs, go to next step.
  34. Clear DTCs. Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, repeat step  2
  35. Allow engine to idle until normal operating temperature is reached. Check for DTCs. If any DTCs are set, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. If no DTCs are set, system is okay.
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