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. 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
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
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 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, P0606, P0607, P060D, P062F, P0685, P0689,
P0690, P1516, P1682, P2610. |
- Ignition OFF for 90 seconds, determine the current vehicle testing altitude. Ignition ON, observe the scan tool MAP Sensor parameter. Compare the parameter to the
Altitude Versus Barometric Pressuretable. The MAP Sensor Pressure parameter should be within the specified range indicated in the table.
⇒ | If the reading is not correct for your altitude, diagnose the MAP sensor. Refer to
DTC P0106. |
- Verify the following scan tool parameters indicate OK when the engine is cranked:
• | Cylinder 1-6 Injector Circuit Short to Ground Test Status |
• | Cylinder 1-6 Injector Circuit Open Test Status |
- Verify the scan tool parameters Cylinder 1-6 Injector Circuit Short to Volts Test Status change from Not Run to OK when the engine is cranked.
- Observe the engine speed parameter while cranking the engine.
⇒ | If engine RPM is not indicated, refer to
DTC P0335. |
- 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.
⇒ | If the test lamp does not illuminate on at least one side of each fuse refer to
DTC P0685 or P0690. |
Important: Additional DTCs may set when using the fuel pump output control.
- Command the fuel pump ON and OFF. The fuel pump should energize when commanded ON, and de-energize when commanded OFF.
- Turn OFF the ignition.
- Install the
CH-48027
. 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).
- 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.