Reduction Agent Injector Checking

Reduction Agent Injector 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.

Special tools, testers and auxiliary items required

• multimeter.

• Wiring diagram.

Test requirements

• The ignition switched off.

Start diagnosis

- Disconnect theReducing Agent Injector (N474) electrical harness connector.

• The exhaust system MUST be at room temperature or the readings will be incorrect.

Checking resistance

- Measure the resistance of the Reducing Agent Injector (N474) terminals.

Specified value: 2.4 Ohms (+/- 1 Ohm)

If the specified value was Not obtained replace the Reducing Agent Injector (N474).

If the specified value was obtained:

Checking voltage

- Turn the ignition switch ON.

- Measure the voltage of the Reducing Agent Injector (N474) harness connector terminal 1 to ground.

Specified value: 11.20 V (+/- 1.5 V)

- Measure the voltage of the Reducing Agent Injector (N474) harness connector terminal 2 to ground.

Specified value: 2.58 V (+/- 0.8 V)

If either of the specified values were Not obtained:

Checking wiring

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

- Using a multimeter, check the Reducing Agent Injector (N474) electrical harness connector to the Engine Control Module (ECM) (J623) electrical harness T94 connector for resistance.





Specified value: 1.5 ohms Max.

If the specification was not obtained:

- Check the wiring for a short circuit to each other, Battery positive, Ground or high resistance.

- If necessary, repair the faulty wiring connection.

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

If no malfunction is detected in the wiring and the voltage readings were Not correct:

- Replace the Engine Control Module (ECM) (J623). Refer to the service manual for removal and installation procedures.

If no malfunction is detected in the wiring and the voltage readings were correct:

- Remove the Reducing Agent Injector (N474) from the exhaust pipe. Refer to the Repair Manual. Check the injector for crystallization formations restricting the flow of reducing agent. Replace the injector if this condition is found.

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 ] Scan Tool Testing and Procedures.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Scan Tool Testing and Procedures.

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