GM Service Manual Online
For 1990-2009 cars only
Table 1: Example (Typical)
Table 2: Fuel Injector Coil Test Procedure - ECT Between 10°C - 35°C (50°F - 95°F)

Object Number: 17707  Size: MF

Test Description

Caution: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete.

  1. The first second of the voltage displayed by the digital multimeter (DMM) may be inaccurate due to the initial current surge. Therefore, record the lowest voltage displayed by the DMM after the first second of the test. The voltage displayed by the DMM should be within the specified range. Refer to the Example. The voltage displayed by the DMM may increase throughout the test as the fuel injector windings warm and the resistance of the fuel injector windings changes. Any large fluctuations in voltage that do not stabilize indicate an intermittent connection within the fuel injector.

Example (Typical)

Resistance Ohms

Voltage Specification at 10°C-35°C (50°F-95°F)

11.4-12.6

5.7-6.6

Fuel Injector Number

Voltage Reading

Pass/Fail

1

5.8

P

2

5.9

P

3

6.2

P

4

4.3

F

Fuel Injector Coil Test Procedure - ECT Between 10°C - 35°C (50°F - 95°F)

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

Use a scan tool in order to observe the engine coolant temperature (ECT).

Is the ECT within the specified range?

10°C-35°C (50°F-95°F)

Go to Step 3

Go to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F)

3

  1. Turn off the ignition.
  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.

  3. Relieve the fuel pressure. Refer to Fuel Pressure Relief
  4. Access the fuel injector connectors as required.
  5. Connect the J 39021 Fuel Injector Tester to B+ and ground.
  6. Set the amperage supply selector switch on the fuel injector tester to the Coil Test 0.5 amp position.
  7. Connect the leads from the digital multimeter (DMM) to the fuel injector tester.
  8. Set the DMM to the tenths scale (0.0).
  9. Connect the fuel injector tester to a fuel injector using the J 39021-380 Fuel Injector Test Harness
  10. Important: Inspect the ECT again to ensure that the correct chart is being used.

  11. Press the Push to Start Test button on the fuel injector tester.
  12. Important: The voltage reading may rise during the test.

  13. Observe the voltage reading on the DMM.
  14. Record the lowest voltage observed after the first second of the test.
  15. Repeat steps 8 through 11 for each fuel injector.

Did any fuel injector have large fluctuations in voltage that do not stabilize or a voltage reading outside of the specified range?

5.7-6.6 V

Go to Step 4

Go to Fuel Injector Balance Test

4

Replace any malfunctioning fuel injectors. Refer to Fuel Injector Replacement .

Did you complete the repair?

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Go to Fuel Injector Balance Test

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