The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that causes an engine not to start. The Engine Cranks but Does Not Run diagnostic table directs the service technician to the appropriate system diagnosis.
The Engine Cranks but Does Not Run diagnostic table assumes the following:
• | The battery is completely charged. Refer to Battery Inspection/Test in Engine Electrical. |
• | The engine cranking speed is acceptable. |
• | There is adequate fuel in the fuel tank. |
Step | Action | Value(s) | Yes | No | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||||||||||
2 |
Does the scan tool display DTCs P0261, P0264, P0267, P0270, P0336, P0601, P0602, P1621, P1631, P0641, P2533? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | 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 - Vehicle in Vehicle DTC Information | Go to Step 4 | ||||||||||||||
4 | Monitor the ignition 1 signal parameter with a scan tool. Is the ignition 1 signal parameter at the specified value? | B+ | Go to Step 5 | Go to Step 11 | ||||||||||||||
5 |
Does the CKP Active Counter increment while cranking the engine? | -- | Go to Step 6 | |||||||||||||||
6 | Command the fuel pump relay ON with a scan tool. Does the fuel pump operate? | -- | Go to Step 7 | |||||||||||||||
7 |
Important: Not grounding the ignition coil housing may cause erratic spark. Does the spark tester spark on all cylinders? | -- | Go to Step 8 | |||||||||||||||
8 |
Does the test lamp blink while the engine is cranking? | -- | Go to Step 9 | |||||||||||||||
9 |
Is the fuel pressure within the specified range while the fuel pump is operating? | 345-414 kPa (50-60 psi) | Go to Step 10 | Go to Fuel System Diagnosis | ||||||||||||||
10 | Inspect for the following conditions:
Did you complete the action? | -- | Go to Step 14 | -- | ||||||||||||||
11 |
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 | ||||||||||||||
12 | Inspect for poor connections at the harness connector of the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairsin Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 | ||||||||||||||
13 | Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||||||||||
14 |
Does the engine start then continue to run? | -- | Go to Step 15 | Go to Step 2 | ||||||||||||||
15 |
Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |