Diagnostic Fault Information
Important: Always perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Attempt to start the engine. Engine should start and run.
Circuit/System Testing
- Crank the engine for up to 30 seconds.
- Observe the Engine DTC information with a scan tool.
- Observe the engine speed parameter while cranking the engine.
- Install a spark tester.
- Crank the engine for 15 seconds. Spark should be observed from the Spark Tester.
- 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:
⇒ | If the testlamp does not illuminate on at least one side of each fuse refer to
DTC P0685
. |
Important: Additional DTCs may set when using the fuel pump output control.
- Command the fuel pump ON and OFF. Fuel pump should energize when commanded ON and De-energize when commanded OFF
- Turn OFF the ignition.
- Install the
J 34730-1A
Fuel Pressure Gage. Turn ON the ignition and command the fuel pump ON while observing the
J 34730-1A
. The fuel pressure
should be between 380-410 kPa (55-60 psi).
- Inspect for the following conditions:
• | Compare the actual engine coolant temperature to the ECT parameter. Refer to DTC P0125. |
• | Air filter and air intake system for restrictions and obstructions |
Repair Instructions
Important: Always perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.