GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 Sonoma Pickup - 4WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 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 cranking speed is within specifications. 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. This step determines if the fuel pump is operating electrically.

Step

Action

Value(s)

Yes

No

1

Did you perform A 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. With a scan tool, observe the DTC information.

Does the scan tool display DTCs  P0230, P0335, P0336, P0601, P0602, P0604, P1626, P1631 or P1683?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3
  1. Attempt to start the engine.
  2. With a scan tool, monitor the Engine Speed parameter while the engine is cranking.

Does the engine speed increment?

--

Go to Step 4

Go to Distributor Ignition (DI) System Diagnosis

4

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 5

Go to Step 10

5

With a scan tool, command the fuel pump ON.

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 Distributor Ignition (DI) System Diagnosis

7
  1. Turn OFF the ignition.
  2. Disconnect the injector connector.
  3. Install the J 34730-375 Injector Test Lamp to an injector connector.
  4. Attempt to start the engine.

Does the test lamp blink while the engine is cranking.

--

Go to Step 8

Go to DTC P0200

8
  1. Turn OFF the ignition.
  2. Install the J 34730-1A Fuel Pressure Gauge . Refer to Fuel System Diagnosis .
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, command the fuel pump ON.

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

414-455 kPa

(60-66 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 (worn timing chain, gears and low compression)--Refer to Symptoms - Engine Mechanical in Engine Mechanical 4.3-L.
    • 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 DTC P0106 .
    • The throttle position (TP) sensor for being stuck in range. Refer to DTC P0121 .

Did you find and correct the condition?

--

Go to Step 11

Go to Intermittent Conditions

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

Did you complete the repair?

--

Go to Step 11

--

11
  1. With a scan tool, clear the DTCs.
  2. Attempt to start the engine.

Does the engine start and continue to operate?

--

Go to Step 12

Go to Step 2

12
  1. Idle the engine.
  2. Allow the engine to reach operating temperature.
  3. With a scan tool, observe the DTC information.

Are any DTCs displayed?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 13

13

With a scan tool, review 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