GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2003 🢒 Aurora 🢒 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.
    • The engine cranking speed is acceptable. Refer to Engine Cranks Slowly in Engine Electrical.
    • There is adequate fuel in the fuel tank.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the DTC information with a scan tool.

Does the scan tool display DTC P0230, P0335, P0340, P0385, P0403, P0404, P0601, P0602, P1404, P0603, P0604, P1621, P1630, P1631?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

Inspect the fuse that supplies ignition voltage to the ignition coil cassettes.

Is the fuse open?

--

Go to Electronic Ignition (EI) System Diagnosis

Go to Step 4

4

Command the fuel pump relay ON with a scan tool.

Does the fuel pump operate?

--

Go to Step 5

Go to Fuel Pump Electrical Circuit Diagnosis

5
  1. Turn OFF the ignition.
  2. Install the J 34730-1A Fuel Pressure Gage. Refer to Fuel Pressure Gage Installation and Removal .
  3. Turn ON the ignition, with the engine OFF.
  4. Command the fuel pump ON with a scan tool.

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

284-325 kPa

(41-47 psi)

Go to Step 6

Go to Fuel System Diagnosis

6

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. If the spark plugs are fouled, determine what caused the condition. Refer to Spark Plug Inspection .
    • 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 manifold absolute pressure (MAP) sensor. Refer to Manifold Absolute Pressure Sensor Replacement .
    • Faulty engine coolant temperature (ECT) sensor. Refer to Engine Coolant Temperature Sensor Replacement .

Did you find and correct the condition?

--

Go to Step 7

Go to Diagnostic Aids

7
  1. Clear the DTCs with a scan tool.
  2. Attempt to start the engine.

Does the engine start and continue to operate?

--

Go to Step 8

Go to Step 2

8
  1. Idle the engine.
  2. Allow the engine to reach operating temperature.
  3. Observe the DTC information with a scan tool.

Are any DTCs displayed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK