Engine Cranks But Does Not Run. Oldsmobile Alero 2002

For 1990-2009 cars only

Makes 🢒 Oldsmobile 🢒 2002 🢒 Alero 🢒 Engine 🢒 Engine Electrical 🢒 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 engine cranking speed is within specifications. Refer to Engine Cranks Slowly in Engine Electrical.

•	There is adequate fuel in the fuel tank.

Test Description

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

While cranking the engine, the crankshaft position (CKP) activity should increment to 255, then rollover to 0.

Step

Action

Value(s)

Yes

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.
With a scan tool, observe the DTC information.

Does the scan tool display DTCs P0336, P0601, P0602, P1621, or P1631?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Attempt to start the engine.
With a scan tool, monitor the CKP activity counter while the engine is cranking.

Does the CKP activity counter increment while cranking the engine?

Go to Step 4

Go to Electronic Ignition (EI) System Diagnosis

Turn On the ignition, with the engine OFF.

Important: Ensure the fuses listed below are not open, before proceeding with this test.

Probe both sides of the following fuses:

•

BATT

•

IGN

•

F/P-Inj

Does the test lamp illuminate on both sides of all the fuses listed?

Go to Step 5

Go to Testing for Short to Ground in Wiring System

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 a fuel pressure gage. 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?

345-414 kPa

(50-60 psi)

Go to Step 7

Go to Fuel System Diagnosis

Turn OFF the ignition.
Remove the ignition coil housing. Refer to Ignition Coil Housing Replacement .

Important: Not grounding the ignition coil housing, may cause erratic spark.

Install a jumper wire with clips on both ends from the top of the ignition control module to ground.
Install the J 36012-A Ignition System Diagnostic Harness.
Install a J 26792 Spark Tester on #1 spark plug jumper wire.
Ground #4 (companion to #1) spark plug jumper wire.
Crank the engine with the remaining spark plug jumper wires connected.
Repeat the above steps by installing the spark tester on #4 and grounding #1. Do the same for #2 and #3 spark plugs. Making sure the companion wire is grounded.

Does the spark tester spark on all cylinders?

Go to Step 8

Go to Electronic Ignition (EI) 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 9

Go to Fuel Injector Circuit Diagnosis

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--Refer to Symptoms - Engine Mechanical in Engine Mechanical.

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

•	The engine coolant temperature (ECT) sensor is NOT close to the actual engine temperature--Refer to DTC P0117 or DTC P0118 .

•	Compare manifold absolute pressure/throttle position (MAP/TP) parameters to another vehicle. The parameters should be close in value. Refer to DTC P0105 .

Did you find and correct the condition?

Go to Step 10

Go to Diagnostic Aids

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

Does the engine start and continue to operate?

Go to Step 11

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 12

With a scan tool review 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