Fuel Injector Solenoid Coil Test. Generic Unit Repair 2008

For 1990-2009 cars only

Makes 🢒 Generic 🢒 2008 🢒 Unit Repair 🢒 Engine 🢒 Engine Controls and Fuel - Ram-Jet 🢒 Fuel Injector Solenoid Coil Test

Diagnostic Instructions

•	Perform the Powertrain On Board Diagnostic (OBD) System Check prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provide an overview of each diagnostic category.

The control module enables the appropriate fuel injector group for each cylinder bank. The ignition voltage is supplied directly to the fuel injectors. The control module controls the fuel injectors by grounding the 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. A fuel injector control circuit DTC may not set, but a misfire may be apparent. 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

•	Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.

•	Perform the fuel injector coil test within the conditions of the customers concern. A fuel injector condition may only be apparent at a certain temperature, or under certain conditions.

Reference Information

Description and Operation

Fuel System Description

Connector End View Reference

Engine Control Module Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Component Testing

Verify the resistance of each fuel injector with one of the following methods:

ECT Within 10-32°C (50-90°F)

The resistance of each fuel injector should be within 11-14 ohms.

⇒	If the resistance of any fuel injector is not within the specified range, replace the fuel injector.

ECT Outside of 10-32°C (50-90°F)

Test and record the resistance of each fuel injector with a DMM.
Subtract the lowest resistance value from the highest resistance value. The difference between the lowest value and the highest value should be equal to or less than 3 ohms.

⇒	If the difference is equal to or less than 3 ohms, refer to Fuel Injector Balance Test for further diagnosis of the fuel injectors.

⇒	If the difference is greater than 3 ohms perform the following:

2.1.	Add all of the fuel injector resistance values to obtain a total resistance value.

2.2.	Divide the total resistance value by the number of fuel injectors to obtain an average resistance value.

2.3.	Replace the fuel injector that displays the greatest resistance difference above or below the average.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Injector Replacement