GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Blazer - 2WD 🢒 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 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. Refer to Battery Inspection/Test in Engine Electrical.
    • The cranking speed is acceptable. Refer to Engine Cranks Slowly in Engine Electrical.
    • There is adequate fuel in the fuel tank.

Step

Action

Value(s)

Yes

No

Schematic Reference: Engine Controls Schematics

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

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 P0230, P0335, P0336, P0601, P0602, P0604, P1626, P1631, or P1683?

--

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

Go to Step 3

3

Does the scan tool display any body control module (BCM) vehicle theft deterrent (VTD) DTCs?

--

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

Go to Step 4

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

Does the engine speed increment?

--

Go to Step 5

Go to Distributor Ignition (DI) System Diagnosis

5

Monitor the ignition 1 signal voltage parameter with a scan tool.

Is the ignition 1 signal voltage parameter at the specified value?

B+

Go to Step 6

Go to Step 10

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 Distributor Ignition (DI) System Diagnosis

8
  1. Turn OFF the ignition.
  2. Install the J 34730-1A Fuel Pressure Gage . Refer to Fuel System Diagnosis .
  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?

379-427 kPa

(55-62 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 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, such as a worn timing chain, gears and low compression--Refer to Symptoms - Engine Mechanical in Engine Mechanical - 4.3L.
    • Restricted exhaust system--Refer to Restricted Exhaust in Engine Exhaust.
    • The engine coolant temperature (ECT) sensor is NOT close to the actual engine temperature.
    • Compare manifold absolute pressure(MAP)/barometric pressure (BARO) parameters to another vehicle. The parameters should be close in value. Refer to DTC P0106 .
    • Throttle position (TP) sensor for being stuck in range--Refer to DTC P0121 .

Did you find complete the action?

--

Go to Step 13

--

10
  1. Test the ignition 1 signal voltage circuit for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  2. Replace the fuse if necessary.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

11

Inspect for poor connections at the harness connector of the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

12

Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the repair?

--

Go to Step 13

--

13
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Attempt to start the engine.

Does the engine start and continue to run?

--

Go to Step 14

Go to Step 2

14

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

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

System OK