Engine Cranks But Does Not Run. Pontiac Aztek

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 2001 🢒 Aztek - FWD 🢒 Body and Accessories 🢒 Wiring Systems 🢒 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.

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. Engine coolant temperature should be within 3°C (5°F) of the intake air temperature. If not, refer to DTC P0128 .

For an intermittent condition, refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

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

If all the Cylinder Injector Circuit Status parameters display Fault, this indicates a condition with the injector supply voltage circuit.

This step determines if the fuel pump is operating electrically.

Step

Action

Values

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 DTC P0101, P0123, P0230, P0601, P0602, P1626, P1630, or P1631?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

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:

•

ELEC ENG

•

Fuel INJ

•	ENG Controls

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

Go to Step 4

Go to Ignition Relay Diagnosis

With a scan tool, monitor the Cylinder 1-6 Injector Circuit Status parameter.
Crank the engine.

Do all of the Cylinder Injector Circuit Status parameters display OK?

Go to Step 5

Go to Fuel Injector Circuit Diagnosis

With a scan tool, command the fuel pump relay ON.

Does the fuel pump turn ON?

Go to Step 6

Go to Fuel Pump Electrical Circuit 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 7

Go to Electronic Ignition (EI) System Diagnosis

Turn OFF the ignition.
Install all disconnected components.
Install the J 34730-1A fuel pressure gauge. Refer to Fuel System Diagnosis .
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 when the fuel pump is operating?

358-405 kPa

(52-59 psi)

Go to Step 8

Go to Fuel System Diagnosis

Inspect for the following conditions:

•	Collapsed air intake duct

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

•	Spark plugs that have been fouled by gas or coolant--Refer to Spark Plug Inspection . If the spark plugs are fouled, determine what caused the condition.

•	Engine mechanical condition, such as 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 P0128 .

•	Compare MAP and/or BARO parameters to another vehicle. The parameters should be close in value. Refer to Manifold Absolute Pressure Sensor Diagnosis .

•	The TP sensor is stuck in range. Refer to DTC P0121 .

Did you find and correct the condition?

Go to Step 9

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 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

With a scan tool, 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