Engine Cranks But Does Not Run. Buick LeSabre 2002

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2002 🢒 LeSabre 🢒 Engine 🢒 Engine Electrical 🢒 Engine Cranks But Does Not Run

Circuit 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.

•	Proper compression--Refer to Engine Compression Test in Engine Mechanical.

•	There is adequate fuel in the fuel tank.

Diagnostic Aids

Using a scan tool, compare engine coolant temperature (ECT) with intake air temperature (IAT) on a completely cool engine. ECT should be within 10°C (18°F) of IAT.

Step

Action

Value(s)

Yes

Schematic Reference: Engine Controls Schematics

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

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

Does the scan tool display DTC P0230, P0336, P0341, P0601, or P0602?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Attempt to start the engine.
Monitor the Engine RPM parameter with a scan tool, while the engine is cranking.

Does the Engine RPM parameter display cranking RPM?

Go to Step 4

Go to Electronic Ignition (EI) System Diagnosis

Command the fuel pump ON with a scan tool.

Does the fuel pump turn ON?

Go to Step 5

Go to Fuel Pump Electrical Circuit Diagnosis

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

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

364-405 kPa (53-59 psi)

Go to Step 6

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 7

Go to DTC P0341

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 8

Go to Electronic Ignition (EI) System Diagnosis

Inspect for the following conditions:

•	Collapsed air intake duct

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

•	Fouled spark plugs--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 Engine Compression Test in Engine Mechanical.

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

•	Faulty/Inaccurate ECT sensor

•	Faulty/Inaccurate MAP sensor--Refer to Manifold Absolute Pressure Sensor Diagnosis .

•	Stuck TP sensor

Did you find and correct the condition?

Go to Step 9

Go to Diagnostic Aids

Clear the DTCs with a scan tool.
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.
Observe the DTC information with a scan tool.

Are any DTCs displayed?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 11

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK