Fuel Injector: Testing and Inspection

Fuel Injectors, Checking

Observe all safety precautions: => [ Safety Precautions ] Safety Precautions

View clean working conditions: => [ Clean Working Conditions ] Clean Working Conditions

Prior to repair work, perform a preliminary check to verify the condition. Refer to => [ Preliminary Check ] Preliminary Check.

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

The following test procedure is used to diagnose all fuel injectors.

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Engine Speed (RPM) Sensor (G28) OK.

• Battery voltage at least 12.5 volts.

• All electrical consumers such as, lights and rear window defroster, switched off.

• Vehicles with automatic transmission, shift selector lever into position "P" or "N".

• A/C switched off.

• Ground connections between engine/transmission/chassis OK.

• Ignition switched Off.

Start diagnosis

- Remove the engine cover.

- Disconnect the Fuel Injector electrical harness connectors from Fuel Injectors (N30, N31, N32, N33).

Checking internal resistance

- Using a multimeter, check the Fuel Injector terminals 1 to 2 for resistance.

Specified value: 178 K to 184 K ohms (at approx. 20° C)

If the specified value was Not obtained:

- Replace the malfunctioning Fuel Injector.

If the specified value was obtained:

Checking wiring

- Remove the Engine Control Module (ECM) (J623). Refer to the Repair Information.

- Using a multimeter, check the Fuel Injector electrical harness connector terminals to the Engine Control Module (ECM) (J623) electrical harness connector T60 terminals for a short to ground or voltage, high resistance or an open circuit. Refer to Wiring Diagrams for Pin locations.






Specified value: 1.5 ohms Max.

If the specified value was Not obtained:

- Check the wiring for an open, high resistance or short to ground or voltage.

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring:

- Replace the Engine Control Module (ECM) (J623). Refer to the Repair Information.

- Install the engine cover with air filter.

Final procedures

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.