2005 PONTIAC GTO

Engine Cranks But Does Not Run

Description

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.

• The engine cranking speed is acceptable. Refer to Engine Cranks Slowly.

• There is adequate fuel in the fuel tank.

STEP ACTION YES NO
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2 Go to Diagnostic System Check - Vehicle
2 1. Turn ON the ignition, with the engine OFF.
2. Observe the DTC information with a scan tool.

Does the scan tool display DTCs P0101, P0108, P0230, P0335, P0336, P0601, P0602, P0604, P0606, P0607, P0641, P0651, P0685, P0689, P0690, P1621, P1630, P1631, P1682, or P2610?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 3
3 Does the scan tool display any body control module (BCM) or vehicle theft deterrent (VTD) DTCs?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 4
4 1. Turn ON the ignition, with the engine OFF.
2. Probe both sides of the fuses located in the underhood electrical center listed below using a test lamp connected to ground.

• The auto trans fuse

• The engine sensor fuse

• The INJ/IGN fuse, even bank

• The INJ/IGN fuse, odd bank

Does the test lamp illuminate on at least one side of each fuse?

Go to Step 5 Go to DTC P0685, P0689, or P0690

5 Command the fuel pump ON with a scan tool.

Does the fuel pump operate?

Go to Step 6

Go to Fuel Pump Electrical Circuit Diagnosis

6 1.Turn OFF the ignition.

2. Disconnect a spark plug wire.

3. Install J 26792 Spark Tester.

4. Attempt to start the engine.

Does the spark tester spark?

Go to Step 7 Go to Electronic Ignition System Diagnosis

7 1. Turn OFF the ignition.

2. Install a fuel pressure gauge. Refer to Fuel Pressure Gauge Installation and Removal.

Important: You may need to command the fuel pump ON a few times to obtain the highest possible fuel pressure.

3. Turn ON the ignition, with the engine OFF.

4. Command the fuel pump ON with a scan tool.

5. Observe the fuel pressure while the fuel pump is operating.

Is the fuel pressure within the specified range?

Go to Step 8 Go to Fuel System Diagnosis

8 Inspect for the following conditions:

• Collapsed air intake duct

• Restricted air filter element--Refer to Air Cleaner Element Replacement.

• Spark plugs for being fouled--Refer to Spark Plug Inspection. If the spark plugs are fouled, determine what caused the condition.

• Engine mechanical condition, for example, broken timing chain, low compression--Refer to Engine Compression Test.

• Restricted exhaust system--Refer to Restricted Exhaust.

• An engine coolant temperature (ECT) sensor that has shifted in value--Refer to Temperature Versus Resistance.

• Compare the MAP parameter to another vehicle. The parameters should be close in value. Refer to DTC P0106.

Did you complete the action?

Go to Step 9

Go to Hard Start

9 1.Clear the DTCs with a scan tool.

2. Attempt to start the engine.

Does the engine start and continue to operate?

Go to Step 10 Go to Step 2

10 1. Idle the engine.

2. Allow the engine to reach operating temperature.

3. Observe the DTC information with a scan tool.

Are any DTCs displayed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK