Engine Cranks But Does Not Run. Pontiac GTO 2004

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 Engine 🢒 Engine Electrical 🢒 Engine Cranks But Does Not Run

Description

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.

Diagnostic Aids

Inspect for the following conditions:

•	Insufficient fuel can cause a no start condition. Thoroughly inspect the fuel delivery system for sufficient fuel volume to the fuel injectors. Inspect the fuel supply components for partial blockage or restrictions.

•	Fuel injectors with partially blocked and restricted nozzles, or a malfunctioning solenoid, can cause a no start condition. Refer to Fuel Injector Solenoid Coil Test and Fuel Injector Balance Test with Tech 2 .

•

There may be fuel spray at the fuel injectors and the indicated fuel pressure may be correct, yet there may not be enough fuel to start the engine. If the fuel injectors and the injector circuit are OK, and fuel spray is detected, the fuel injector ON time may be inadequate. If the PCM receives incorrect inputs from the various information sensors, the fuel delivered by the fuel injectors may be inadequate to start the engine. Check all the engine data parameters with a scan tool and compare the values indicated with the expected values or the values from a known good vehicle.

•	Inspect the engine for good secure electrical grounds. Refer to Engine Controls Schematics .

•

Water or foreign material in the fuel can cause a no start or engine will not stay running condition. During freezing weather water can freeze inside the fuel system. The engine may start after 30 minutes in a heated repair shop. The malfunction may not recur until parked overnight in freezing temperatures. Extreme weather conditions can cause contaminated fuel to prevent the vehicle from starting.

•	A malfunctioning EFI relay, also called ENGINE CONTROL relay, or a malfunctioning fuel pump relay can cause a no start. Inspect the each relay for the following conditions:

-	Check the electrical resistance of the relay. The resistance across the coil side terminals is 65-95 ohms at 20°C (68°F). Measure for infinite resistance across the switch side terminals.

-	The relay electrical contacts may be pitted or sticking. Replace the relay if tapping gently on the relay or wiggling the relay causes a change in the relay's operation.

-	The performance of the relay may be affected by temperature. Test the relay after sitting outside overnight and after running the engine 30 minutes.

•

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.

•	An intermittent malfunction may be caused by fault in any of the critical information or component electrical circuits. Inspect the wiring harness and the components for an intermittent condition. Refer to Intermittent Conditions .

Use the following relay cavity table in order to locate the correct cavities to probe during diagnosis. The table layout corresponds to the cavity layout of the relay block, with the bottom of the table representing the front of the vehicle.

Relay Cavity Identification
Coil Power
Coil Ground	Empty	Switch Load
Switch Power

Test Description

The number below refers to the step number on the diagnostic table.

If a DTC B0576 is present, the EFI relay, also called ENGINE CONTROL relay, may be malfunctioning. The EFI relay supplies voltage to the fuel injectors, ignition coils, and other vehicle components. When the EFI relay is not operating properly, a no start condition occurs.

Step

Action

Values

Yes

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

Crank the engine for the specified amount of time.

Does the scan tool display any DTCs that failed this ignition?

15 seconds

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Inspect the following control modules for DTCs related to the vehicle theft deterrent system:

•	Engine or powertrain control module (ECM/PCM)

•	Powertrain interface module (PIM)

•	Body control module (BCM)

Does the scan tool display any vehicle theft deterrent system DTCs?

Go to Diagnostic Starting Point - Theft Deterrent in Theft Deterrent

Go to Step 4

Inspect the PIM for a DTC B0576.

Is a B0576 set?

Go to Step 11

Go to Step 5

Use the scan tool to monitor the engine speed while cranking the engine.

Is engine RPM indicated on the scan tool?

Go to Step 6

Go to DTC P0335

Use the scan tool in order to enable the fuel pump. Refer to Scan Tool Output Controls .
Listen at the fuel tank for pump operation.

Does the fuel pump operate?

Go to Step 7

Go to Fuel Pump Electrical Circuit Diagnosis

Turn OFF the ignition.
Disconnect a spark plug wire.
Install J 26792 Spark Tester.
Attempt to start the engine.

Does the HEI Spark Tester indicate a crisp, blue spark?

Go to Step 8

Go to Electronic Ignition (EI) System Diagnosis

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 9

Go to DTC P0118

Turn OFF the ignition.
Install a fuel pressure gauge. Refer to Fuel Pressure Gage Installation and Removal .

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.

Turn ON the ignition, with the engine OFF.
Observe the fuel pressure while 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

Perform the following additional inspections:

•	Inspect the duct work between the mass air flow (MAF) sensor and the throttle body for air leaks.

•	Ensure that the throttle angle is at 0 percent at a closed throttle. If the throttle angle is not at 0 percent , refer to DTC P0122 or DTC P0123 .

•

A malfunctioning MAF sensor may cause a no start or a stall after a start. If you suspect this, disconnect the MAF sensor. The PCM will default to the speed density in order to calculate the engine load and the intake air flow. If disconnecting the MAF sensor corrects the condition and the connections are OK, replace the MAF sensor. Refer to Mass Airflow Sensor Replacement .

•	Inspect the spark plugs for gas fouling. Refer to Spark Plug Inspection in Engine Electrical.

•	Inspect for an engine mechanical failure, such as timing chain, low compression. Refer to Engine Compression Test in Engine Mechanical.

•	Compare the MAP/BARO parameters to another vehicle. The parameter values should be close to each other.

Did you find and correct the condition?

Go to Step 19

Go to Hard Start

Turn OFF the ignition.
Remove the EFI relay from the relay block-underhood.
Turn ON the ignition, leaving the engine OFF.
Probe the fuse block side of the relay positive voltage circuit, at terminal 30, using a test lamp connected to ground. Refer to the Relay Cavity Identification table in Diagnostic Aids.

Does the test lamp illuminate?

Go to Step 12

Go to Step 18

Probe the fuse block side of the relay coil positive voltage circuit, at terminal 85, using a test lamp connected to ground.

Does the test lamp illuminate?

Go to Step 13

Go to Step 18

Turn OFF the ignition.
Probe the fuse block side of the relay coil ground circuit, at terminal 86, using a test lamp connected to B+.
Observe the test lamp.

Does the test lamp illuminate?

Go to Step 15

Go to Step 14

Repair the open or poor connection in the EFI relay coil ground circuit between the EFI relay and G102. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 19

Turn OFF the ignition.
Use a fused jumper wire to connect EFI relay fuse block terminal 30 to terminal 87.
Turn ON the ignition, with the engine OFF.
Use a test lamp to test for ignition positive voltage at either of the FUEL INJECTORS AND IGNITION COIL fuses in the Fuse Block-Underhood.

Does the test lamp illuminate?

Go to Step 17

Go to Step 16

Repair the open or poor connection in the EFI relay circuit 1139, between the relay and both FUEL INJECTORS AND IGNITION COIL fuses. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 19

Replace the EFI or ENGINE CONTROL relay.

Did you complete the replacement?

Go to Step 19

Repair the open or poor connection in the ignition positive voltage circuit. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 19

Use the scan tool in order to select the Diagnostic Trouble Codes (DTC) option and the Clear DTC Information.
Attempt to start the engine.

Does the engine start and continue to run?

Go to Step 20

Go to Step 2

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?

Go to Diagnostic Trouble Code (DTC) List

System OK