Table 1: | Example |
Table 2: | Fuel Injector Coil Test -- ECT Between 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 from 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:
• | Faulty terminal connection--Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, 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, go to Fuel Injection Coil Test - ECT Between 10°C-35°C.
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. The voltage displayed by the DMM should be within the specified value, refer to the example. The voltage displayed by the DMM may increase throughout the test as the fuel injectors windings warm and the resistance changes. An erratic reading indicates an intermittent connection within the fuel injector and the fuel injector must be replaced. A fuel injector outside the specified value is considered faulty and must be replaced.
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 | 6.3 | P |
2 | 5.9 | P |
3 | 6.2 | P |
4 | 6.1 | P |
5 | 4.8 | F |
6 | 6.0 | P |
Step | Action | Values | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | ||||||
Does the temperature measure between the specified value? | 10°-35°C (50°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 outside the specified value? | 5.7-6.6 volts | |||||||
4 |
Did you find and correct the condition? | -- | ||||||
5 | Replace the faulty fuel injectors. Refer to Fuel Injector Replacement . Is the action complete? | -- | -- | |||||
6 | Does any driveabilty condition still exist? | -- | Go to applicable diagnostic procedure | System OK |