Engine Cranks But Does Not Run. GMC Truck Yukon XL Denali 2006

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2006 🢒 Yukon XL Denali 🢒 Engine 🢒 Engine Controls - 8.1L 🢒 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 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 .

•	The engine cranking speed is acceptable. Refer to Engine Cranks Slowly .

•	There is adequate fuel in the fuel tank.

Step

Action

Values

Yes

Schematic Reference: Engine Controls Schematics

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

Important: DO NOT allow the ignition switch to be interrupted during this step.

Crank the engine for the specified amount of time.

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

15 seconds

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 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

Turn ON the ignition, with the engine OFF.
Probe both test points of the PCM 1 fuse located in the underhood fuse block, with a test lamp connected to a good ground.

Does the test lamp illuminate on at least one test point of the fuse

Go to Step 5

Go to Ignition Relay Diagnosis

Turn OFF the ignition.
Disconnect the spark plug wire from the spark plug.
Install the J 26792 Spark Tester to the spark plug wire.
Attach the clamp end of the spark tester to a good engine ground.
Observe the spark tester.
Crank the engine.
Repeat the test for the remaining cylinders.

Does the spark tester produce a spark on all cylinders?

Go to Step 6

Go to Electronic Ignition (EI) System Diagnosis

Monitor the ignition 1 signal parameter with a scan tool.

Is the ignition 1 signal parameter at the specified value?

B+

Go to Step 7

Go to Step 10

Command the fuel pump ON with a scan tool.

Does the fuel pump operate?

Go to Step 8

Go to Fuel Pump Electrical Circuit Diagnosis

Turn OFF the ignition.
Install a fuel pressure gage. Refer to Fuel System Diagnosis .

Important: The fuel pump operates for about 2 seconds when the ignition is turned ON. The fuel pressure must be observed when the fuel pump is operating.

Turn ON the ignition, with the engine OFF.
Observe the fuel pressure while the fuel pump is operating.

Is the fuel pressure within the specified range?

385-425 kPa (55-62 psi)

Go to Step 9

Go to Fuel System Diagnosis

Inspect for the following conditions:

•	The engine coolant temperature (ECT) sensor is not close to the actual engine temperature.

•	The duct work between the mass air flow (MAF) sensor and the throttle body for air leaks

•	A restricted exhaust system--Refer to Restricted Exhaust .

•

A malfunctioning MAF sensor may cause a no start or a stall after a start. If you suspect this, disconnect the MAF sensor. The powertrain control module (PCM) will default to the speed density in order to calculate the engine load and the intake air flow. If disconnecting the MAF sensor corrects the condition and the connections are OK. Refer to DTC P0102 .

•	The spark plugs for being gas fouled--Refer to Spark Plug Inspection .

•	An engine mechanical failure that causes an engine not to start such as timing chain, low compression--Refer to Symptoms - Engine Mechanical and Engine Compression Test .

•	Compare the MAP/BARO parameters to another vehicle. The parameter values should be close to each other.

Did you complete the action?

Go to Step 13

Test the ignition 1 voltage circuit for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Replace the fuse if necessary.

Did you find and correct the condition?

Go to Step 13

Go to Step 11

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 12

Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 13

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

Does the engine start the continue to run?

Go to Step 14

Go to Step 2

Allow the engine to reach operating temperature.
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