Diagnostic Instructions
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
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Special Tools Required
Circuit/System Verification
Attempt to start the engine. The engine should start and run.
Circuit/System Testing
- Crank the engine for up to 30 seconds.
- 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
to diagnose those DTCs: P0016, P0201-P0206, P0335, P0336, P0351-P0353, P0601, P0602, P0604,
P0606, P0685, P1516, P2610 |
- Ignition ON, verify the scan tool injector circuit status parameters indicate Incomplete.
- Observe the engine speed parameter while cranking the engine.
- Install a
J 26792
.
- Crank the engine for 15 seconds. Spark should be observed from the
J 26792
.
- 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 test lamp 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
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 380-410 kPa (55-60 psi).
- 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 |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.