Fuel Injectors, Checking

Fuel Injectors, Checking

Observe all safety precautions: => [ Safety Precautions ] Generic Scan Tool

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

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.

Special tools, testers and auxiliary items required

• multimeter.

• Diode test lamp (12V).

• 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 (GND) connections between engine/transmission/chassis OK.

• Ignition switched off.

- Observe safety precautions.

- Observe rules for cleanliness.

Test procedure

- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check

Start diagnosis

- Remove the engine cover and air intake duct. Refer to appropriate service manual.






- Disconnect the Fuel Injector electrical harness connectors from Fuel Injectors (N30, N31, N32, N33, N83, N84).

Checking internal resistance

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

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

If the specified value was Not obtained:

- Replace the malfunctioning Fuel Injector.

If the specified value was obtained:

Checking wiring

If the manufacturers test box is being used, perform the following step.

- Install the test box.

If the manufacturers test box is not being used, perform the following step.

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

- Using a multimeter, check the Fuel Injector electrical harness connector terminals to the Engine Control Module (ECM) (J623) electrical harness connector T105 terminals for a short to ground or voltage, high resistance or an open circuit.






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 Manual.

- 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 ] Programming and Relearning.