Engine Cranks But Does Not Run

Engine Cranks but Does Not Run

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

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. Battery Inspection/Test Engine Cranks Slowly

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 vehicle DTC information with a scan tool.

^ If any of the following DTCs are set, Refer to Diagnostic Trouble Code (DTC) List - Vehicle : P0201-P0206, P0335, P0336, P0351-P0353, P0601, P0602, P0604, P0685, P1516, P2610 Diagnostic Trouble Code Descriptions P0201 P0335 P0336 P0601 P0685

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

^ If engine RPM is not indicated, Refer to Electronic Ignition (EI) System Diagnosis. Electronic Ignition (EI) System Diagnosis

4. Install a J 26792.
5. Crank the engine for 15 seconds. Spark should be observed from the J 26792.

^ If spark is not observed Refer to Crankshaft Position Sensor System Diagnosis. Component Tests and General Diagnostics

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 test point for the following fuses:

* Emission fuse
* Ignition 1 fuse

^ If the test lamp does not illuminate on at least one side of each fuse Refer to DTC P0685. P0685

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

7. Command the fuel pump ON and OFF. Fuel pump should energize when commanded ON, and de-energize when commanded OFF

^ If the fuel pump does not respond, Refer to Fuel Pump Electrical Circuit Diagnosis. Component Tests and General Diagnostics

8. Turn OFF the ignition.
9. Install the CH-48027 Digital Pressure Gage. Turn ON the ignition and command the fuel pump ON while observing the CH-48027. The fuel pressure should be between 384-425 kPa (56-62 psi).

^ If the fuel pressure is not within 384-425 kPa (56-62 psi), Refer to Fuel System Diagnosis. Component Tests and General Diagnostics

10. 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.
* Inspect the spark plug and spark plug wires.
* Test the exhaust system for restrictions.

Repair Instructions

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