Engine Cranks But Does Not Start

Engine Cranks But Does Not Start

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 (Battery Inspection/Test) , and Engine Cranks Slowly (Engine Cranks Slowly). Fuel level and fuel quality should be determined for correct diagnosis.

Reference Information
Schematic Reference

Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
* Starting System Description and Operation (Description and Operation)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information
Special Tools Required

* CH 48027-100 - Digital Pressure Gage
* J 26792 (SA91992) - HEI Spark Tester

Circuit/System Verification

Attempt to start the engine. 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.

• If any of the following DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions) to diagnose those DTCs: P0201-P0204, P0230, P0231, P0232, P023F, P025A, P0335, P0336, P0351-P0354, P0601, P0602, P0603, P0604, P0606, P0607, P060E, P062F, P0685, P0689, P0690, P069E, P1516, P1682, P2610, P2635.

3. Observe the engine speed parameter while cranking the engine.

• If engine RPM is not indicated, refer to Electronic Ignition System Diagnosis (Electronic Ignition System Diagnosis).

4. Install a J 26792 (SA91992) - Tester.
5. Crank the engine for 15 seconds. Spark should be observed from the Spark Tester.

• If spark is not observed, refer to Electronic Ignition System Diagnosis (Electronic Ignition System Diagnosis).

6. With the ignition ON and the engine OFF, test the fuses that are supplied by the powertrain relay for voltage. The test lamp should illuminate at each fuse test point.

• If the test lamp does not illuminate on at least one side of each fuse, refer to DTC P0685 or P0690 (P0685).

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

7. Install the CH 48027-100 - Gage. Turn ON the ignition and command the fuel pump ON while observing the CH 48027-100 - Gage. The fuel pressure should be between 345-414 kPa (50-60 psi).

• If the fuel pressure is not within 345-414 kPa (50-60 psi), refer to Fuel System Diagnosis ().

8. Inspect for the following conditions:

* Compare the actual engine coolant temperature to 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 (Alcohol/Contaminants-in-Fuel Diagnosis).
* Inspect the spark plugs. Refer to Spark Plug Inspection (Testing and Inspection).
* Test the exhaust system for restrictions. Refer to Restricted Exhaust (Restricted Exhaust).

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Spark Plug Replacement (Service and Repair)