GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2005 🢒 Grand Am 🢒 Engine 🢒 Engine Electrical 🢒 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 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. Refer to Engine Cranks Slowly in Engine Electrical.
    • There is adequate fuel in the fuel tank.

Test Description

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

  1. While cranking the engine, the crankshaft position (CKP) activity should increment to 255, then rollover to 0.

Step

Action

Values

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
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the DTC information with a scan tool.

Does the scan tool display DTCs P0336, P0601, P0602, P1621, P1631, or P1632?

--

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

  1. Attempt to start the engine.
  2. Monitor the crankshaft position (CKP) activity counter while the engine is cranking with a scan tool.

Does the CKP activity counter increment while cranking the engine?

--

Go to Step 6

Go to Electronic Ignition (EI) System Diagnosis

6

Command the fuel pump ON with a scan tool.

Does the fuel pump operate?

--

Go to Step 7

Go to Fuel Pump Electrical Circuit Diagnosis

7
  1. Turn OFF the ignition.
  2. Remove the ignition coil housing. Refer to Ignition Coil Housing Replacement .

    3. Important: Not grounding the ignition coil housing, may cause erratic spark.

  3. Install a jumper wire with clips on both ends from the top of the ignition control module to ground.
  4. Install the J 36012-A Ignition System Diagnostic Harness.
  5. Install a J 26792 Spark Tester on #1 spark plug jumper wire.
  6. Ground #4 (companion to #1) spark plug jumper wire.
  7. Crank the engine with the remaining spark plug jumper wires connected.
  8. Repeat the above steps by installing the spark tester on #4 and grounding #1. Do the same for #2 and #3 spark plugs. Making sure the companion wire is grounded.

Does the spark tester spark on all cylinders?

--

Go to Step 8

Go to Electronic Ignition (EI) System Diagnosis

8
  1. Turn OFF the ignition.
  2. Disconnect an injector connector.
  3. Install the J 34730-405 Injector Test Lamp to the injector connector.
  4. Attempt to start the engine.

Does the test lamp blink while the engine is cranking?

--

Go to Step 9

Go to Fuel Injector Circuit Diagnosis

9
  1. Turn OFF the ignition.
  2. Install a fuel pressure gage. Refer to Fuel Pressure Gage Installation and Removal .
  3. Turn ON the ignition, with the engine OFF.
  4. Command the fuel pump ON with a scan tool.

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:

    • Collapsed air intake duct
    • Restricted air filter element--Refer to Air Cleaner Element Replacement .
    • Spark plugs for being gas or coolant fouled--Refer to Spark Plug Inspection . If the spark plugs are fouled, determine what caused the condition.
    • Engine mechanical condition, worn timing chain and gears, low compression--Refer to Symptoms - Engine Mechanical and Engine Compression Test in Engine Mechanical.
    • Restricted exhaust system--Refer to Restricted Exhaust in Engine Exhaust.
    • An engine coolant temperature (ECT) sensor that has shifted in value--Refer to Temperature Versus Resistance .
    • Compare manifold absolute pressure (MAP)/throttle position (TP) parameters to another vehicle. The parameters should be close in value.

Did you complete the action?

--

Go to Step 14

--

11
  1. Test the ignition 1 signal voltage circuit supplied by the PCM IGN fuse for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  2. Replace the fuse if necessary.

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 powertrain control module (PCM). 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 14

Go to Step 13

13

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 14

--

14
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Attempt to start the engine.

Does the engine start then continue to run?

--

Go to Step 15

Go to Step 2

15
  1. Allow the engine to reach operating temperature.
  2. Observe the DTC information with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK