Test Description

WARNING: This page is about a different variant/trim than selected.

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

2: The engine coolant temperature (ECT) affects the ability of the fuel injector tester to detect a faulty fuel injector.
3: The first second of the voltage displayed by the 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 may increase throughout the test as the fuel injector windings warm and the resistance of the fuel injector windings changes. An erratic voltage reading, or large fluctuations in voltage that do not stabilize, indicates an intermittent connection within the fuel injector. From the voltages recorded, identify the highest voltage, excluding any voltages of more than 9.5 volts. Subtract each voltage that is not more than 9.5 volts from the highest voltage. Record each subtracted value. Refer to the Example. The subtracted value for any fuel injector must not exceed 0.8 volt. A fuel injector with a subtracted value that is more than 0.6 volt is considered faulty and must be replaced. A fuel injector with a recorded voltage of more than 9.5 volts is also considered faulty and must be replaced.

Example

Highest Voltage Reading		Acceptable Subtracted Value Above/Below 10°C-35°C (50°F-95°F)
7.1 V		0.6 V
Injector Number	Voltage	Subtracted Value	Pass/Fail
1	9.8	-	F
2	6.6	0.5	P
3	6.9	0.2	P
4	5.8	1.3	F

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

Step	Action	Values	Yes	No
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC information
2	Install a scan tool. Check the engine coolant temperature with the scan tool. Is the engine coolant temperature outside the specified range?	10-35°C (50-95°F)	Go to Step 3	Go to Fuel Injector Coil Test - Engine Coolant Temperature (ECT) Between 10-35 Degrees C (50-95 Degrees F)
3	Turn OFF the ignition. CAUTION: Refer to FUEL GAGE LEAK CAUTION in Cautions and Notices. NOTE: 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. Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure . Connect the J 39021 Fuel Injector Tester to B+ and to ground. See Special Tools . Set the amperage supply selector switch on the fuel injector tester to the Coil Test 0.5 amp position. Connect the leads from a DMM to the fuel injector tester. Refer to the illustration associated with the test description. Set the DMM to the tenths scale (0.0). Disconnect the fuel injector electrical connector. Use 2 jumper wires from the J 35616 Connector Test Adapter Kit in order to connect the fuel injector to the J 39021 test leads. See Special Tools . IMPORTANT: Check the engine coolant temperature again to ensure that the correct chart is being used. Press the Push to Start Test button on the fuel injector tester. Observe the voltage reading on the DMM. IMPORTANT: The voltage reading may rise during the test. Record the lowest voltage observed after the first second of the test. Repeat step 7 through step 11 for each fuel injector. Identify the highest voltage reading recorded other than those more than 9.5 volts. Subtract any other voltage reading recorded from the highest voltage reading recorded. Repeat step 14 for all the remaining fuel injectors. Is any value that resulted from the subtraction more than the specified value?	1 V	Go to Step 4	Go to Fuel Injector Balance Test with Special Tool
4	Replace any fuel injector that had any of the following: A subtracted value exceeding 0.6 volts An initial reading of more than 9.5 volts An erratic reading Refer to Fuel Injector Replacement . Is the replacement complete?	-	Go to Fuel Injector Balance Test with Special Tool	-