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 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 acceptable. Refer to Engine Cranks Slowly in Engine Electrical.
    • There is adequate fuel in the fuel tank.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

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

1

Did you perform the Diagnostic System Check-Engine Controls?

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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 P0101, P0108, P0230, P0335, P0336, P0601, P0602, P0604, P0606, P0641, P1626, or P1631?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

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

--

Go to Diagnostic System Check - Theft Deterrent in Theft Deterrent

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.
  3. • ODD INJR/Coil
    • EVEN INJR/Coil

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

--

Go to Step 5

Go to Main Relay Circuit 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. 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 (EI) System Diagnosis

7

  1. Turn OFF the ignition.
  2. Install a fuel pressure gauge. Refer to Fuel Pressure Gage Installation and Removal .
  3. Important: You may need to command the fuel pump ON a few times in order to obtain the highest possible fuel pressure.

  4. Turn ON the ignition, with the engine OFF.
  5. Command the fuel pump ON with a scan tool.
  6. 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 8

Go to Fuel System Diagnosis

8

Inspect for the following conditions:

    • Collapsed air intake duct
    • Restricted air filter element--Refer to Air Cleaner Assembly Replacement .
    • Contaminated fuel--Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • 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 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 the MAP parameter to another vehicle. The parameters should be close in value. Refer to DTC P0106 .

Did you complete the action?

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Go to Step 9

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9

  1. With a scan tool, clear the DTCs.
  2. Attempt to start the engine.

Does the engine start and continue to operate?

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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

System OK