The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that causes an engine to not start. The diagnostic table directs the service technician to the appropriate system diagnosis. The diagnostic table assumes the following conditions are met:
• | The battery is completely charged. Refer to Battery Inspection/Test in Engine Electrical. |
• | The engine cranking speed is acceptable. Refer to Engine Cranks Slowly in Engine Electrical. |
• | There is adequate fuel in the fuel tank. |
Step | Action | Values | Yes | No | ||||||||||||||||
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Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||||||||||
1 | Did you perform the Diagnostic System Check--Engine Controls? | -- | Go to Step 2 | |||||||||||||||||
2 |
Does the scan tool display DTCs P0102, P0113, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P208, P0261, P0264, P0267, P0270, P0273, P0276, P0279, P0282, P0335, P0336, P0601, P0602, P0604, P0606, P0628, P0629, P0686, P0687, P0689, P0690, P1626, P1631, or P1636? | -- | Go to Step 3 | |||||||||||||||||
3 | Does the scan tool display any body control module (BCM) vehicle theft deterrent (VTD) DTCs? | -- | Go to Diagnostic Trouble Code (DTC) List in Theft Deterrent | Go to Step 4 | ||||||||||||||||
4 |
Does the test lamp illuminate on at least one test point of the fuse? | -- | Go to Step 5 | Go to Main Relay Diagnosis | ||||||||||||||||
5 | Observe the engine speed parameter on the scan tool, while cranking the engine. Does the scan tool display 0 RPM? | -- | Go to Step 9 | Go to Step 6 | ||||||||||||||||
6 |
Did the spark tester spark on all cylinders? | -- | Go to Step 7 | |||||||||||||||||
7 |
Important: The engine coolant temperature (ECT) must be below the operating temperature in order to avoid irregular fuel pressure readings due to hot soak fuel boiling.
Important: The fuel pump may need to be commanded ON a few times in order to obtain the highest possible fuel pressure. Is the fuel pressure within the specified range? | 380-410 kPa (55-60 psi) | Go to Step 8 | Go to Fuel System Diagnosis | ||||||||||||||||
8 | Inspect for the following conditions:
Did you complete the action? | -- | Go to Step 15 | |||||||||||||||||
9 |
Did you find and correct the condition. | -- | Go to Step 15 | Go to Step 10 | ||||||||||||||||
10 |
Did you replace the sensor? | -- | Go to Step 15 | Go to Step 11 | ||||||||||||||||
11 |
Did you replace a sensor? | -- | Go to Step 15 | Go to Step 12 | ||||||||||||||||
12 | Test the 12-volt reference circuits of the following components for a short to ground. Refer to Circuit Testing in Wiring Systems.
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13 | ||||||||||||||||
13 | Test for shorted terminals and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 | ||||||||||||||||
14 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||||||||||||
15 |
Does the engine start and continue to operate? | -- | Go to Step 16 | Go to Step 2 | ||||||||||||||||
16 |
Are any DTCs displayed? | -- | System OK |