The diagnostic table identifies 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 within specification. Refer to Engine Cranks Slowly in Engine Electrical. |
• | There is adequate fuel in the fuel tank. |
Inspect for the following conditions:
• | The mass air flow (MAF) is compared to a calculated mass air flow based upon the manifold absolute pressure (MAP), the throttle position (TP), and the engine RPM. A skewed or unresponsive MAP sensor at key on will cause the predicted air flow value to be inaccurate. Compare the MAP and TP readings to that of a known good vehicle. |
• | A faulty engine coolant temperature (ECT) sensor. Use a scan tool in order to compare the ECT with the intake air temperature (IAT) on a completely cooled engine. The ECT should be within 3°C (5°F) of the IAT. |
• | For an intermittent condition, refer to Intermittent Conditions . |
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||||||
2 | Crank the engine for the specified amount of time. Does the scan tool display any DTCs that failed this ignition? | 15 seconds | Go to Step 3 | |||||||||||||
3 | Inspect the body control module (BCM) for DTCs related to the vehicle theft deterrent (VTD) system. Does the scan tool display any BCM vehicle theft deterrent DTCs? | -- | Go to Diagnostic System Check - Theft Deterrent in Theft Deterrent | Go to Step 4 | ||||||||||||
4 | Monitor the engine speed while cranking the engine. Is engine RPM indicated on the scan tool? | -- | Go to Step 5 | Go to DTC P0335 | ||||||||||||
Does the test lamp illuminate on both sides of the fuses? | -- | Go to Step 6 | Go to Ignition Relay Diagnosis | |||||||||||||
6 |
Does the HEI Spark Tester spark? | -- | Go to Step 7 | |||||||||||||
7 | Use the scan tool in order to monitor the engine coolant temperature (ECT). Is the ECT on the scan tool close to the actual engine temperature? | -- | Go to Step 8 | Go to DTC P0118 | ||||||||||||
8 | Use the scan tool in order to enable the fuel pump. Does the fuel pump operate? | -- | Go to Step 9 | |||||||||||||
9 |
Important: The fuel pump operates for about 2 seconds when the ignition is turned ON. The fuel pressure must be observed when the fuel pump is operating. Is the fuel pressure within the specified range? | 379-427 kPa (55-62 psi) | Go to Step 10 | Go to Fuel System Diagnosis | ||||||||||||
10 | Perform the following additional inspections:
Did you find and correct the condition? | -- | Go to Step 11 | Go to Hard Start | ||||||||||||
11 |
Does the engine start and continue to run? | -- | Go to Step 12 | Go to Step 2 | ||||||||||||
12 |
Are any DTCs displayed? | -- | Go to Step 13 | |||||||||||||
13 | Use the scan tool in order to select the Capture Info option and the Review Info option. Are any DTCs displayed that you have not diagnosed? | -- | System OK |