Code No. P0203: No. 3 Injector Circuit Malfunction

OPERATION

Driving power is supplied from the engine-ECU (terminal No. 2) to the No. 3 injector (terminal No. 1).
The engine-ECU (terminal No. 3 and No. 4) turn on the power transistor to flow current to the No. 3 injector (terminal No. 2).

FUNCTION

The engine-ECU monitors peak current during injector drive control to detect disconnection in the No. 3 injector circuit.

TROUBLE JUDGMENT

Check Conditions

Ignition switch is in ON position
Battery positive voltage is 8 V or more.
Except during the engine cranking period
When an engine-ECU internal capacitor is allowed to be charged

Judgment Criterion

When the peak current of the injector circuit is not detected, the circuit is judged to be open.

PROBABLE CAUSES

Failed No. 3 injector
Open/short circuit in injector circuit or loose connector contact
Failed engine-ECU

caution

A high-tension voltage is flowing between the engine-ECU and the injectors while the engine is running. Handle them carefully to avoid receiving electric shocks from the voltage.

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-120 No. 3 injector connector

Q. Is the check result normal?

	Go to Step 2 .

	Repair or replace the connector.

STEP 2. Check No. 3 injector itself.

Check No. 3 injector itself (Refer to ).

Q. Is the check result normal?

	Go to Step 3 .

	Replace the No. 3 injector. After replacing the Injector, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

STEP 3. Check harness between No. 3 injector connector and engine-ECU connector.

note

Before checking harness, check intermediate connector D-111, and repair if necessary.

Check the harness between B-120 (terminal No. 2) No. 3 injector connector and D-213 (terminal No. 3) engine-ECU connector.
Check the harness between B-120 (terminal No. 2) No. 3 injector connector and D-213 (terminal No. 4) engine-ECU connector.

Check earthing line for open/short circuit and damage.

Q. Are the check results normal?

	Go to Step 4 .

	Repair the damaged harness wire.

STEP 4. Check harness between B-120 (terminal No. 1) No. 3 injector connector and D-213 (terminal No. 2) engine-ECU connector

note

Before checking harness, check intermediate connector D-111, and repair if necessary.

Check power supply line for open/short circuit and damage.

Q. Is the check result normal?

	Go to Step 5 .

	Repair or replace the connector.

STEP 5. Connector check: D-213 engine-ECU connector

Q. Is the check result normal?

	Go to Step 6 .

	Repair or replace the connector.

STEP 6. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?

Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing

). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns

). After registering the injector identification code, the vehicle equipped with the DPF carries out the forcible DPF regeneration. (Refer to GROUP 17 - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).