GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 Savana 🢒 Engine 🢒 Engine Controls - 6.5L (L65) 🢒 Engine Cranks But Does Not Run

Circuit Description

This table verifies that all basic engine systems are operating properly. This includes the battery condition, the engine cranking speed, the glow plugs, and the fuel delivery system.

Diagnostic Aids

If no trouble is found and the cause of an Engine Cranks But Does Not Run has not been found, check for the following conditions:

    • Proper cranking speed, 100 RPM cold--180 RPM hot (a scan tool can be used to check cranking speed by pulling the ENG 1 fuse and monitoring Engine Speed on scan tool while cranking).
    • Water or foreign material in the fuel system
    • Basic engine condition

If the crankshaft position sensor and the optical/fuel temperature are disconnected or malfunctioning at the same time, an Engine Cranks But Does Not Run condition will exist.

Test Description

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

  1. This step checks for proper cranking speed (see Diagnostic Aids).

    2.

  2. This step will check the ground wire on the injection pump (wire located on top of pump).

    3.

  3. This step will determine if the injection pump or wiring is at fault.

    4.

  4. This step will determine if the fuel injection control voltage is present by probing at the black/gray 4 wire connector jumper harness, instead of at the 6 wire pump connector.

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

Check for proper condition of batteries. Refer to Battery Inspection/Test in Engine Electrical.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 3

3
  1. Check for adequate fuel in the tank.
  2. Add fuel as necessary.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 4

4

Check the quality of fuel..

Did you find and correct the condition?

--

Go to Step 23

Go to Step 5

5
  1. Check the glow plug system operation. Refer to Glow Plug System Diagnosis .
  2. Repair as necessary.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 6

6

  1. Check for proper cranking speed.
  2. Repair as necessary. Refer to Engine Cranks Slowly in Engine Electrical.

Did you find and correct the condition?

100 RPM cold

180 RPM hot

Go to Step 23

Go to Step 7

7
  1. Check the fuel supply system. Refer to Fuel System Diagnosis .
  2. Repair as necessary.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 8

8

  1. Check the injection pump ground wire, located on top of the injection pump.
  2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 9

9

Install the scan tool.

Does the scan tool display data?

--

Go to Step 10

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

10

Monitor the vehicle theft deterrent (VTD) Fuel Disabled parameter on the Powertrain engine data list.

Does the VTD Fuel Disabled parameter display Active while cranking the engine?

--

Go to Diagnostic System Check - Theft Deterrent in Theft Deterrent

Go to Step 11

11
  1. Loosen the injector line at the injector.
  2. Crank the engine.
  3. Repeat for the remaining injectors.

Is there fuel at the each injection line?

--

Go to Symptoms - Engine Controls

Go to Step 12

12

Disconnect the optical/fuel temperature sensor.

Does the vehicle start?

--

Go to Step 16

Go to Step 13

13

  1. Reconnect the optical/fuel temperature sensor.
  2. Disconnect the fuel solenoid driver at the fuel injection pump 4-wire jumper harness.
  3. With a DMM connected to ground, probe the fuel injector control circuit (terminal A) at the 4-wire jumper harness connector on the PCM side.
  4. Crank the engine.

Does the voltage measure more than or equal to the specified value?

1.2 V

Go to Step 14

Go to Step 17

14
  1. Verify that the fuel solenoid driver 4-wire jumper harness is still disconnected.
  2. Probe the fuel solenoid closure ground circuit (terminal B) with a test lamp connected to B+ at the harness terminal at the PCM side.

Does the test lamp illuminate?

--

Go to Step 15

Go to Step 18

15
  1. Turn ON the ignition with the engine OFF.
  2. Verify the fuel solenoid driver 4-wire jumper harness is still disconnected.
  3. Probe the ignition feed circuit (terminal C) at the fuel solenoid 4-wire jumper harness connector on the PCM side with a test lamp connected to ground.

Does the test lamp illuminate?

--

Go to Step 16

Go to Step 20

16

Replace the fuel injection pump. Refer to Fuel Injection Pump Replacement .

Did you complete the replacement?

--

Go to Step 23

--

17

Check the fuel injection control circuit for an open or short to ground between the fuel solenoid driver and the PCM.

Was a condition found?

--

Go to Step 21

Go to Step 19

18

Check the closure ground circuit for an open between the fuel solenoid driver and the PCM.

Was a condition found?

--

Go to Step 21

Go to Step 19

19

Inspect the fuel solenoid driver connector and PCM connector for proper connection.

Was a condition found?

--

Go to Step 21

Go to Step 22

20

Repair the open in the ignition feed circuit.

Did you complete the repair?

--

Go to Step 23

--

21

Repair the circuit as necessary.

Did you complete the repair?

--

Go to Step 23

--

22

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 23

--

23
  1. Use the scan tool in order to select DTC, Clear Info.
  2. Attempt to start the engine.

Does the engine start and continue to run?

--

Go to Step 24

Go to Step 2

24
  1. Allow the engine to idle until the normal operating temperature is reached.
  2. Select DTC, Fail This Ign.

Are any DTCs displayed?

--

System OK

Go to Diagnostic Trouble Code (DTC) List