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For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Century 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 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.

Test Description

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

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

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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 P0101, P0123, P0230, P0340, P0601, P0602, P1626, P1630, or P1631?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 3

3
  1. Turn ON the ignition, with the engine OFF.
  2. Probe both sides of the FUEL INJR fuse and the ELEK IGN fuse with a test lamp connected to a good ground.

Does the test lamp illuminate on at least one side of each fuse?

--

Go to Step 4

Go to Ignition Relay Diagnosis

4
  1. Attempt to start the engine.
  2. Observe the engine RPM parameter while the engine is cranking with a scan tool.

Does the engine RPM parameter display cranking RPM?

--

Go to Step 5

Go to Electronic Ignition (EI) System Diagnosis

5

Command the fuel pump ON with a scan tool.

Does the fuel pump turn ON?

--

Go to Step 6

Go to Fuel Pump Electrical Circuit Diagnosis

6
  1. Turn OFF the ignition.
  2. Disconnect a spark plug wire.
  3. Install the J 26792 Spark Tester to the spark plug wire.
  4. Attempt to start the engine.

Does the spark tester spark?

--

Go to Step 7

Go to Electronic Ignition (EI) System Diagnosis

7

While monitoring the Cylinder 1-6 Injector Circuit Status parameter with a scan tool, crank the engine.

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

--

Go to Step 8

Go to Fuel Injector Circuit Diagnosis

8
  1. Turn OFF the ignition.
  2. Install all disconnected components.
  3. Install the J 34730-1A Fuel Pressure Gage. Refer to Fuel Pressure Gage Installation and Removal .
  4. Turn ON the ignition, with the engine OFF.
  5. Command the fuel pump ON with a scan tool.

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

358-405 kPa

(52-59 psi)

Go to Step 9

Go to Fuel System Diagnosis

9

Inspect for the following conditions:

    • Collapsed air intake duct
    • Restricted air filter element
    • 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--For example, 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 (MAP)/barometric pressure (BARO) parameters to another vehicle. The parameters should be close in value. Refer to Manifold Absolute Pressure Sensor Diagnosis .
    • The throttle position (TP) sensor for being stuck in range--Refer to DTC P0121 .
    • Loose or unseated mass air flow (MAF) sensor connector--Loose terminals or a connector not fully seated may allow erratic MAF sensor signals. Refer to Testing for Proper Terminal Contact in Testing for Intermittent Conditions and Poor Connections , Inducing Intermittent Fault Conditions , and Testing for Electrical Intermittents in Wiring Systems.

Did you complete the action?

--

Go to Step 10

--

10
  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 11

Go to Step 2

11
  1. Allow the engine to idle until the engine reaches the normal operating temperature.
  2. Inspect for any DTCs with a scan tool.

Are any DTCs displayed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK