Engine Cranks But Does Not Run. Chevrolet Chevrolet C-Series Medium Duty Truck B7 2001

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2001 🢒 Chevrolet C-Series Medium Duty Truck B7 🢒 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 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 cranking speed is within specifications. Refer to Engine Cranks Slowly in Engine Electrical.

•	There is adequate fuel in the fuel tank.

Diagnostic Aids

Inspect for the following conditions:

•

Mass air flow (MAF) is compared to a calculated mass air flow based upon the manifold absolute pressure (MAP), throttle position (TP), and engine RPM readings. A skewed or unresponsive MAP sensor at KEY ON will cause the predicted air flow value to be inaccurate. Compare MAP and TP sensor values to that of a known good vehicle.

•	Faulty engine coolant temperature (ECT) sensor. Using a scan tool, compare engine coolant temperature with intake air temperature (IAT) on a completely cool engine. The engine coolant temperature should be within 3° C (5° F) of the intake air temperature.

For an intermittent condition, refer to Intermittent Conditions .

Test Description

The number below refers to the step number on the diagnostic table.

This step determines if the ignition relay is providing the listed circuit breakers with voltage.

This step determines if the fuel pump is operating electrically.

Step

Action

Values

Yes

Did you perform A Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

Turn ON the ignition, with the engine OFF.
With a scan tool, observe the DTC information.

Does the scan tool display DTCs P0230, P0335, P0336, P0601, P0602, P0604, P0606, P1626, P1631 or P1683?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Turn on the ignition, with the engine off.
Probe both sides of the following circuit breakers with a test lamp connected to ground.

•

Odd INJ

•

Even INJ

Does the test lamp illuminate on both sides of the circuit breakers?

Go to Step 4

Go to Ignition Relay Diagnosis

Turn OFF the ignition.
Disconnect a spark plug wire.
Install the J 26792 spark tester to the spark plug wire.
Attempt to start the engine.

Does the spark tester spark?

Go to Step 5

Go to Electronic Ignition (EI) System Diagnosis

With a scan tool, command the fuel pump ON.

Does the fuel pump turn ON?

Go to Step 6

Go to Fuel Pump Electrical Circuit Diagnosis

Turn OFF the ignition.
Install the J 34730-1A fuel pressure gauge. Refer to Fuel Pressure Gage Installation and Removal .
Turn ON the ignition, with the engine OFF.
With a scan tool, command the fuel pump ON.

Is the fuel pressure within the specified range while the fuel pump is operating?

384-425 kPa

(55-62 psi)

Go to Step 7

Go to Fuel System Diagnosis

Turn OFF the ignition.
Disconnect an injector connector.
Install the J 34730-405 injector test lamp to the injector connector.
Attempt to start the engine.

Does the test lamp blink while the engine is cranking?

Go to Step 8

Go to DTC P0200

Inspect for the following conditions:

•	Collapsed air intake duct

•	Restricted air filter element--Refer to Air Cleaner Element Replacement .

•	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, etc.). Refer to Symptoms - Engine Mechanical in Engine Mechanical-8.1L.

•	Restricted exhaust system--Refer to Restricted Exhaust in Engine Exhaust.

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

•	Compare MAP/BARO parameters to another vehicle. The parameters should be close in value.

Did you find and correct the condition?

Go to Step 9

Go to Diagnostic Aids

Use a scan tool in order to clear the DTCs.
Attempt to start the engine.

Does the engine start and continue to operate?

Go to Step 10

Go to Step 2

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

Are any DTCs displayed?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 11

Use a scan tool in order to observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK