Code No. P0201: No. 1 Injector Circuit Malfunction

OPERATION

Driving power is supplied from the engine-ECU connector terminal I/B1 to the No. 1 injector connector terminal.
The engine-ECU connector terminal INJ1 turn on the power transistor to flow current to the No. 1 injector connector terminal.

FUNCTION

The engine-ECU monitors peak current during injector drive control to detect disconnection in the injector circuit.

TROUBLE JUDGEMENT

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

Judgement Criterion

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

FAIL-SAFE AND BACKUP FUNCTION

The throttle valve is opened (electrical discontinuity).
The EGR control is stopped (fully closed).
The DPF regeneration is prohibited.

PROBABLE CAUSES

Failed No. 1 injector
Open/short circuit or harness damage in No. 1 injector circuit or loose connector contact
Failed engine-ECU

DIAGNOSIS PROCEDURE

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.

STEP 1. Check No. 1 injector itself.

Check No. 1 injector itself (Refer to ).

Q. Is the check result normal?

	Go to Step 2.

	Replace the No. 1 injector.

STEP 2. Check of open circuit, short to earth, and damage in INJ1 line between No. 1 injector connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector(s) or wiring harness.

STEP 3. Check of open circuit, short to earth, and damage in I/B1 line between No. 1 injector connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 4.

	Repair the connector(s) or wiring harness.

STEP 4. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?

	Replace the engine-ECU.

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