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 the fuel flow to pulse.
Test the engine fuel injection harness for the following conditions:
• | Inspect the harness connectors for the following conditions. 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. |
• | Backed-out terminals |
• | Improper mating |
• | Broken locks |
• | Improperly formed or damaged terminals |
• | Faulty terminal-to-wire connections |
• | 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 within the specified range, go to the 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 injector's 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? | -- | ||||||
Is the engine coolant temperature within the specified range? | 10°-35°C (50°-95°F) | |||||||
Important : The 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 range? | 5.7-6.6 V | |||||||
4 |
Did you find and correct the condition? | -- | ||||||
5 | Replace the faulty fuel injectors. Refer to Fuel Injector Replacement Did you complete the replacement? | -- | -- | |||||
6 | Does any driveability condition still exist? | -- | Go to the applicable diagnostic tables | System OK |