GM Service Manual Online
For 1990-2009 cars only

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.
    • There is adequate fuel in the fuel tank.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

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 P0261, P0264, P0267, P0270, P0336, P0601, P0602, P1621, P1631, P0641, P2533?

--

Go to Diagnostic Trouble Code (DTC) List

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 in Theft Deterrent

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 CMP resync counter parameter while the engine is cranking, with a scan tool.

Does the CMP resync counter increment while cranking the engine?

--

Go to Step 6

Go to Electronic Ignition (EI) System Diagnosis

6

Command the fuel pump relay 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 fuel pump relay.
  3. Remove the ignition coil housing. Refer to Ignition Coil Housing Replacement .
  4. Important: Not grounding the ignition coil housing, may cause erratic spark.

  5. Install a jumper wire with clips on both ends from the top of the ignition coil housing to ground.
  6. Install the J 36012-A (J 43883) Ignition Test Wires.
  7. Install a J 26792 (SA9199Z) Spark Tester on the #1 spark plug jumper wire.
  8. Connect the #4 (companion to #1) spark plug jumper wire to ground.
  9. Crank the engine with the remaining spark plug jumper wires connected.
  10. Repeat the above steps by installing the spark tester on the #4 jumper and grounding the #1 jumper.
  11. 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 a fuel injector connector.
  3. Install the J 34730-405 Injector Test Lamp (Noid Light) to the fuel 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 SA9127E Gage Bar Set. Refer to Fuel Pressure Gage Installation and Removal .
  3. Turn ON the ignition, with the engine OFF.
  4. Command the fuel pump relay 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:

    • A collapsed air intake duct
    • A restricted air filter element--Refer to Air Cleaner Element Replacement .
    • The spark plugs for being gas or coolant fouled--Refer to Spark Plug Inspection . If the spark plugs are fouled, determine what caused the condition.
    • Any engine mechanical conditions, worn timing chain and gears, or low compression--Refer to Symptoms - Engine Mechanical and Engine Compression Test in Engine Mechanical.
    • A restricted exhaust system--Refer to Restricted Exhaust in Engine Exhaust.
    • An inaccurate engine coolant temperature (ECT) sensor--Refer to DTC P0117 or DTC P0118 .
    • An inaccurate manifold absolute pressure (MAP) sensor or throttle position (TP) sensor--Refer to DTC P0106 .

Did you complete the action?

--

Go to Step 14

--

11

  1. Test the ignition 1 voltage circuits that are supplied by the ECM 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 ECM. 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 ECM. Refer to Engine 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

System OK