GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 GMC K Sierra - 4WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Fuel Injector Solenoid Coil Test

Object Number: 35909 Size: MF

Test Description

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

  1. This step is used in order to set up the injector coil test. Also read the instructions included with the tools used for this test.

    2.

  2. The engine coolant temperature affects the ability of the tool to detect a faulty injector. If the engine coolant temperature is not between 10°C and 35°C (50°F and 95°F), allow the vehicle to warm or cool as necessary.

    3.

  3. Due to a current surge, the first second of the voltage reading may be inaccurate. Record the lowest voltage after the first second of the voltage reading. The voltage specification should be within the specified range. The voltage reading may increase throughout the test as the injector windings warm up and the resistance changes. An erratic voltage reading, one that jumps up and down, indicates an intermittent connection within the fuel injector.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

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Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Caution: The fuel pump will operate for 2 seconds after you have turned off the ignition. Make sure that all the fuel pipes and fittings are securely fastened in order to prevent personal injury.

  1. Turn the ignition OFF.

    2. Notice: In order to prevent flooding of a single cylinder and possible engine damage, relieve the fuel pressure before performing the fuel injector coil test procedure.

  2. Relieve the fuel pressure. Refer to Fuel Pressure Relief .
  3. Reconnect the negative battery cable.
  4. Connect the J 39021 fuel injector tester to B+ and ground.
  5. Connect the J 39021-210 injector switch box.
  6. Set the amperage supply selector switch to the Coil Test 0.5 amp position.
  7. Connect the leads from the DMM to the fuel injector tester.
  8. Set the DMM to the tenths scale (0.0).
  9. Connect the scan tool.
  10. Monitor the engine coolant temperature.

Is the engine coolant temperature within the specified range?

10°-35°C (50°-95°F)

Go to Step 4

Go to Step 3

3

Allow the engine to warm or cool as necessary.

Is the engine coolant temperature within the specified range?

10°-35°C (50°-95°F)

Go to Step 4

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4

Important: Perform the following test for each injector.

  1. Press the Push To Start Test button on the fuel injector tester.

    2. Important: The voltage reading may rise during the test. Watch for erratic readings, such as voltage that jumps up and down.

  2. Observe the voltage reading on the DMM.

Do any of the injector voltage readings fall outside the specified range?

5.44-7.53 V

Go to Step 5

Go to Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool

5

Replace the faulty fuel injectors. Refer to Fuel Injector Replacement .

Is the replacement complete?

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Go to Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool

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