Fuel Injector Solenoid Coil Test w/LLT
Diagnostic Instructions
Circuit/System Description
The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. The ECM supplies a high voltage control circuit and a low control circuit to each of the fuel injectors. The control module controls each fuel injector control
circuit via a solid state device called a driver. A fuel injector coil winding resistance that is too high or too low will affect the engine driveability. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings
will increase as the temperature of the fuel injector increases.
Diagnostic Aids
| • | Monitoring the misfire current counters, or misfire graph, may help to isolate the fuel injector that is causing the condition. |
| • | If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool Fuel Injector Circuit Test Status parameter. The Fuel Injector Circuit Test Status parameter will change from OK
or Not Run to Fault if there is a condition with the circuit or a connection. |
Reference Information
Schematic Reference
Engine Controls Schematics
Electrical Information Reference
Component Testing
Important:
| • | The engine coolant must be within the specified range or mis-diagnosis will occur. |
| • | The resistance test must be performed at the fuel injector or mis-diagnosis will occur. |
| • | The DMM and test leads must be calibrated to 0 ohms in order to prevent mis-diagnosis. |
- Engine coolant between 10-32°C (50-90°F).
- Test for 1.30-1.73 ohms between the terminals of the fuel injector. The resistance of each fuel injector should be 1.30-1.73 ohms.
| ⇒ | If not within the specified range, replace the fuel injector. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Fuel Injector Replacement
