GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 Envoy - 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 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 acceptable. Refer to Engine Cranks Slowly in Engine Electrical.
    • There is adequate fuel in the fuel tank.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. The crankshaft position (CKP) sensor can fail in such a way that will cause the engine to crank but will not run. The engine will be able to run by using the cam sensor when the CKP sensor is disconnected.

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. With a scan tool, observe the DTC information.

Does the scan tool display DTC P0107, P0601, P0602, P0604, P0606, P0607, P1220, P1221, P1271, P1514, P1621, P1631, P1635, P1639, P1680, P1681, or P1683?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

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 4

Go to Step 10

4

Command the fuel pump ON with a scan tool.

Does the fuel pump turn ON?

--

Go to Step 5

Go to Fuel Pump Electrical Circuit Diagnosis

5
  1. Turn OFF the ignition.
  2. Remove an ignition coil. Refer to Ignition Coil Replacement .
  3. Install the J 26792 Spark Tester to the coil boot.
  4. Attempt to start the engine.

Does the spark tester spark?

--

Go to Step 6

Go to Electronic Ignition (EI) System Diagnosis

6
  1. Turn OFF the ignition.
  2. Disconnect the fuel injector harness multi-way connector.
  3. Probe a fuel injector control circuit, PCM side, with a test lamp connected to battery voltage.
  4. Crank the engine.

Does the test lamp flash when cranking the engine?

--

Go to Step 7

Go to Fuel Injector Circuit Diagnosis

7
  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?

334-375 kPa

(48-52 psi)

Go to Step 8

Go to Fuel System Diagnosis

8

  1. Disconnect the crankshaft position (CKP) sensor.
  2. Attempt to start the engine.

Does the engine start and continue to run?

--

Go to Step 11

Go to Step 9

9

Inspect for the following conditions:

    • A collapsed air intake duct
    • A restricted air filter element--Refer to Air Cleaner Element Replacement .
    • The spark plugs for being gas or coolant fouled--Refer to Spark Plug Inspection . If the spark plugs are fouled, determine what caused the condition.
    • An engine mechanical condition (worn timing chain, gears and low compression)--Refer to Symptoms - Engine Mechanical in Engine Mechanical.
    • A 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 MAP/BARO parameters to another vehicle. The parameters should be close in value. Refer to DTC P0105 .
    • The TP sensor for being stuck in range--Refer to DTC P1221 .

Did you complete the action?

--

Go to Step 12

--

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

Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement .

Did you complete the replacement?

--

Go to Step 12

Go to Step 2

12
  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 13

Go to Step 2

13
  1. Allow the engine to reach operating temperature.
  2. Observe the DTC information with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK