Table 1: | Example |
Table 2: | Fuel Injector Coil Test -- ECT Outside 10°C-35°C (50°F-95°F) |
The Powertrain Control Module (PCM) controls the fuel injector control circuit using a multi function driver (MFD). Power is supplied by the injector fuse to the injector and is grounded by the PCM. The MFD controls the injector ground, allowing fuel flow to pulse.
Test the engine fuel injection harness for the following conditions:
• | Poor terminal connection. |
Inspect the harness connectors for |
- | Backed out terminals |
- | Improper mating |
- | Broken locks |
- | Improperly formed or damaged and faulty terminal to wire connections |
• | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. |
• | Damaged harness. |
Inspect the wiring harness for damage. Refer to Wiring Repairs in Wiring Systems. |
The numbers below refer to the step numbers on the Diagnostic Table.
The engine coolant temperature affects the resistance in the fuel injector and the ability of the fuel injector tester to detect a faulty fuel injector. If the engine coolant temperature is between the specified value, refer to Fuel Injection Coil Test - ECT Between 10°C-35°C.
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. 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 change. An erratic voltage reading (large fluctuations in voltage that does not stabilize indicates an intermittent connection within the fuel injector. From the voltages recorded, identify the highest voltage, excluding any voltages above 9.5 volts. A fuel injector with a recorded voltage above 9.5 volts is also considered faulty and must be replaced.
Subtract each voltage from the highest recorded voltage below 9.5 volts. Record each subtracted value. Refer to the example. The subtracted value for any fuel injector must not exceed 0.6 volt. A fuel injector with a subtracted value that is greater than the specified value is considered faulty and must be replaced.
Highest Voltage Reading | Acceptable Subtracted Value Above/Below 10°C-35°C (50°F-95°F) | ||
---|---|---|---|
7.1 Volts | 0.6 Volts | ||
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 |
5 | 7.0 | 0.1 | P |
6 | 7.1 | 0.0 | P |
Step | Action | Value(s) | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you preform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
Does the temperature measure outside the specified value? | 10°C-35°C (50°F-95°F) | |||||||
Important : Fuel system must not be pressurized. Refer to Fuel Pressure Relief .
Does any fuel injector have an erratic reading or a reading above the specified value? | 9.5 volts | |||||||
Does any subtracted value exceed the specified value? | .6 volts | |||||||
5 |
Did you find and correct the condition? | -- | ||||||
6 | Replace the faulty fuel injectors. Refer to Fuel Injector Replacement . Did you complete the replacement? | -- | -- | |||||
7 | Does any driveabilty condition still exist? | -- | Go to the applicable DTC table | System OK |