GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 GMC K Sierra - 4WD (CNG) 🢒 Engine 🢒 Engine Controls - 6.0L 🢒 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 on either fuel system. 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 within specifications. Refer to Engine Cranks Slowly in Engine Electrical.
    • There is adequate fuel in both of the fuel tanks.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check Alternative Fuels - Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Alternative Fuels (Engine Controls)

2
  1. Crank the engine for the specified amount of time.
  2. Observe the diagnostic trouble code (DTC) information from the alternative fuel ECM with a scan tool.

Does the scan tool display DTC P0336 failed this ignition?

15 seconds

Go to DTC P0336

Go to Step 3

3

With a scan tool, observe the diagnostic trouble code (DTC information from the following control modules:

    • alternative fuels ECM
    • PCM

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

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 4

4
  1. With a scan tool, establish communication with the PCM.
  2. Observe the engine speed data parameter.
  3. Crank the engine.

Does the scan tool indicate engine speed while the engine is cranking?

--

Go to Step 5

Go to Electronic Ignition (EI) System Diagnosis in Engine Controls in the C/K Pickup Service Manual

5
  1. Turn OFF the ignition.
  2. Disconnect a spark plug wire from a spark plug.
  3. Install the J 26792 Spark Tester to the spark plug wire.
  4. Attempt to start the engine.

Does the spark tester spark and is the spark consistent?

--

Go to Step 6

Go to Electronic Ignition (EI) System Diagnosis in Engine Controls in the C/K Pickup Service Manual

6
  1. Turn OFF the ignition.
  2. Disconnect the harness connector of a CNG fuel injector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition feed circuit of the CNG fuel injector, with a test lamp connected to a known good ground.

Does the test lamp illuminate?

--

Go to Step 7

Go to Fuel Injector Circuit Diagnosis

7

Is this a Bi-Fuel vehicle (KL6)?

--

Go to Step 8

Go to Step 9

8
  1. Turn OFF the ignition.
  2. Disconnect the alternative fuels ECM connector C003. Refer to Alternative Fuels Engine Control Module Replacement .
  3. Attempt to start the engine.

Does the engine start and idle?

--

Go to Fuel System Diagnosis

Go to Step 9

9

Inspect for the following conditions:

    • Compare MAP parameter to another vehicle. The parameters should be close in value. Refer to DTC P0106 .
    • Collapsed air intake duct
    • Restricted air filter element--Refer to Air Cleaner Element Replacement in Engine Controls in the C/K Pickup Service Manual.
    • Spark plugs for being gas or coolant fouled. Refer to Spark Plug Inspection in Engine Controls in the C/K Pickup Service Manual. If the spark plugs are fouled, determine what caused the condition.
    • Engine mechanical condition, for example, broken timing chain, low compression. Refer to Symptoms - Engine Mechanical in Engine Mechanical in the C/K Pickup Service Manual.
    • Restricted exhaust system. Refer to Restricted Exhaust in Engine Exhaust in the C/K Pickup Service Manual.
    • The engine coolant temperature (ECT) sensor is not close to the actual engine temperature. Refer to Temperature Versus Resistance in Engine Controls in the C/K Pickup Service Manual
    • TP sensor for being stuck in range.

Did you find and correct the condition?

--

Go to Step 10

Go to Intermittent Conditions

10
  1. With a scan tool, clear the DTCs.
  2. Attempt to start the engine.

Does the engine start and continue to operate?

--

Go to Step 11

Go to Step 2

11
  1. Idle the engine.
  2. Allow the engine to reach operating temperature.
  3. With a scan tool, observe the DTC information.

Are any DTCs displayed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK