GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

This Engine Cranks but Does Not Run is an organized approach to identify a condition which causes the engine to crank but not start. This diagnostic directs the technician to the appropriate system diagnosis.

This diagnostic assumes the system voltage levels are adequate for starter motor operation. Refer to Battery Inspection/Test and Engine Cranks Slowly . Fuel level and fuel quality should be determined for correct diagnosis.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  Starting System Description and Operation

Scan Tool Reference

Scan Tool Data List

Special Tools

    • CH-48027-100 Digital Pressure Gage
    • J 26792 HEI Spark Tester

Circuit/System Verification

Attempt to start the engine. The engine should start and run.

Circuit/System Testing

  1. Crank the engine for up to 30 seconds.
  2. Observe the engine DTC information with a scan tool.
  3. If DTCs P0102, P0171, P0201-P0204, P0230, P0335, P0336, P0340, P0443, P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P0685, P0689, P0690, P1516, P1682, P2610 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose those DTCs.
  4. Install a spark tester.
  5. Crank the engine for 15 seconds. Spark should be observed from the spark tester.
  6. If spark is not observed, refer to Electronic Ignition (EI) System Diagnosis .

    Important: Additional DTCs may set when using the fuel pump output control.

  7. Command the fuel pump ON and OFF. The fuel pump should energize when commanded ON and de-energize when commanded OFF.
  8. If the fuel pump does not respond, refer to Fuel Pump Electrical Circuit Diagnosis .
  9. Turn OFF the ignition.
  10. Install the CH-48027-100 . Turn ON the ignition and command the fuel pump ON while observing the CH-48027-100 . Refer to Fuel Pressure Gage Installation and Removal . The fuel pressure should be between 345-414 kPa (50-60 psi).
  11. If the fuel pressure is not within 345-414 kPa (50-60 psi), refer to Fuel System Diagnosis .
  12. Inspect for the following conditions:
  13. • Compare the actual engine coolant temperature to the ECT parameter.
    • The air filter and air intake system for restrictions and obstructions
    • Test the fuel for contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    •  Inspect the spark plugs. Refer to Spark Plug Inspection .
    • Test the exhaust system for restrictions. Refer to Restricted Exhaust .
    • Engine mechanical conditions such as worn timing chain gears, low compression, etc. Refer to Engine Compression Test .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.