GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2006 🢒 Cobalt 🢒 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 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?

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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 P0017, P0201, P0202, P0203, P0204, P0335, P0336, P0601, P0602, P0603, P0604, P0606, P0607, P0641, P0651, P1621, P1630, P1631, P1680, P1681, 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) 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 engine control module (ECM)/ engine coolant temperature (ETC) fuse with a test lamp connected to a good ground.

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

--

Go to Step 5

Go to Powertrain Relay Diagnosis

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. Remove the ignition coil housing.

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

  3. Install a jumper wire from the ignition control module to a good 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. Ensure that the companion wire is grounded.

Does the spark tester spark on all cylinders?

--

Go to Step 7

Go to Electronic Ignition (EI) System Diagnosis

7
  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 8

Go to Fuel Injector Circuit Diagnosis

8
  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 9

Go to Fuel System Diagnosis

9

Inspect for the following conditions:

    • Collapsed air intake duct
    • Restricted air filter element--Refer to Air Cleaner Element Replacement .
    • Contaminated fuel--Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • 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 .
    • Restricted exhaust system--Refer to Restricted Exhaust .
    • An ECT sensor that has shifted in value--Refer to Temperature Versus Resistance .
    • A skewed manifold absolute pressure (MAP) sensor-- Refer to Altitude Versus Barometric Pressure .

Did you complete the action?

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Go to Step 10

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10
  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 11

Go to Step 2

11
  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

System OK