GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2009 🢒 SLS 🢒 Engine 🢒 Engine Controls and Fuel - 4.6L (LH2) 🢒 Engine Cranks But Does Not Run

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 system approach to identify a condition which causes the engine to start but not crank. The Diagnosis lead the technician to carry appropriate system diagnosis.

The Diagnosis assume system voltage class sufficiently started 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

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Description and Operation

Starting System Description and Operation

Scan Tool Reference

Scan Tool Data List

Special Tools

    • CH-48027 Digital Fuel Pressure Gage
    • J 26792 High-energy Ignition Spark Tester

Circuit/System Verification

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

Circuit/System Testing
  1. Crank the engine for no more than 15 seconds.
  2. Observe the Engine DTC information with a scan tool.
    3. ⇒DTC P0102, P0171, P0201-P0208, P0230, P0335, P0336, P0340, P0403, P0404, 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.
  3. Install a spark tester.
  4. Start the engine for 15 seconds. Spark should be observed from the Spark Tester.
    5. ⇒If not observed spark, refer to Electronic Ignition (EI) System Diagnosis.

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

  5. Command the fuel pump ON and OFF. Fuel pump should energize when commanded ON and De-energize when commanded OFF.
  6. Turn the ignition OFF.
  7. Install a CH-48027 . Turn the ignition ON, command the fuel pump ON while observing. Refer to Fuel Pressure Gage Installation and Removal. The fuel pressure should be between 384-425 kPa (55-61 psi).
    8. ⇒If the fuel pressure is not within 384-425 kPa (55-61 psi), refer to Fuel System Diagnosis.
  8. Inspect for the following conditions:
    9. • Compare the actual engine coolant temperature with the ECT parameter.
    • 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 condition, such as worn timing chain gears, low compression, refer to Engine Compression Test.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.