GM Service Manual Online
For 1990-2009 cars only

Description

The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that prevents an engine from starting. 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.
    • The engine cranking speed is within specifications.
    • 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 value to that of a known good vehicle.
    • A faulty engine coolant temperature (ECT) sensor. Compare the ECT with intake air temperature (IAT) on a completely cool engine with a scan tool. The ECT should be within 3°C (5°F) of the IAT. If not, refer to DTC P0128 .

For an intermittent condition, refer to Intermittent Conditions .

Step

Action

Value(s)

Yes

No

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

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

  1. Turn ON the ignition, with the engine OFF.
  2. Inspect the following fuses for an open:
  3. • F/P INJR
    • ELEK IGN
    • F/PMP

Did you find an open fuse?

--

Go to Step 10

Go to Step 4

4

  1. Attempt to start the engine.
  2. Monitor 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

  1. Monitor the Cylinder 1-6 Injector Circuit Status parameter with a scan tool.
  2. Crank the engine.

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

--

Go to Step 6

Go to Fuel Injector Circuit Diagnosis

6

Command the fuel pump ON with a scan tool.

Does the fuel pump turn ON?

--

Go to Step 7

Go to Fuel Pump Electrical Circuit Diagnosis

7

  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 8

Go to Electronic Ignition (EI) System Diagnosis

8

  1. Turn OFF the ignition.
  2. Connect all disconnected components.
  3. Install the J 34730-1A Fuel Pressure Gauge. Refer to Fuel Pressure Gage Installation and Removal .
  4. Turn ON the ignition, with the engine OFF.
  5. 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 9

Go to Fuel System Diagnosis

9

Inspect for the following conditions:

    • Collapsed air intake duct
    • Restricted air filter element--Refer to Air Cleaner Assembly 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. 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/barometric pressure (MAP/BARO) parameters to another vehicle. The parameters should be close in value. Refer to Manifold Absolute Pressure Sensor Diagnosis .
    • TP sensor for being stuck in range--Refer to DTC P0121 .

Did you find and correct the condition?

--

Go to Step 11

Go to Diagnostic Aids

10

  1. Repair the short to ground on the circuit supplied by the open fuse. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the fuse.

Did you complete the action?

--

Go to Step 11

--

11

  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 12

Go to Step 2

12

  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

System OK