Code No. P0201: No. 1 Injector System

OPERATION

Power is supplied to the No. 1 injector (terminal No. 1) from the engine control relay (terminal No. 4).
The engine-ECU (terminal No. 8) makes the power transistor in the unit be in "ON" position, and that makes currents go on the No. 1 injector (terminal No. 2).

FUNCTION

The engine-ECU controls the power supply interval of the No. 1 injector.
The fuel injection amount of the No. 1 injector depends on the power supply interval.

TROUBLE JUDGMENT

Check Condition

While engine is running.

Judgment Criterion

Injector coil surge voltage (battery positive voltage + 2 V) has not been detected for 2 seconds.

PROBABLE CAUSES

Failed No. 1 injector
Open or shorted No. 1 injector circuit, harness damage, or connector damage
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III actuator test

Item No. 1: No. 1 injector

OK: Idling state varies.

Q. Is the check result normal?

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

	Go to Step 2 .

STEP 2. Connector check: A-101 No. 1 injector connector

Q. Is the check result normal?

Go to Step 3 .

Repair or replace the connector.

STEP 3. Check No. 1 injector itself.

Check No. 1 injector itself (Refer to ).

Q. Is the check result normal?

	Go to Step 4 .

	Replace the No. 1 injector.

STEP 4. Perform voltage measurement at A-101 No. 1 injector connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 1 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 6 .

Go to Step 5 .

STEP 5. Connector check: B-206 engine control relay connector

Q. Is the check result normal?

Check power supply line for open/short circuit.

Repair or replace the connector.

STEP 6. Connector check: B-206 engine control relay connector

Q. Is the check result normal?

Go to Step 7 .

Repair or replace the connector.

STEP 7. Check harness between B-206 (terminal No. 4) engine control relay connector and A-101 (terminal No. 1) No. 1 injector connector.

note

Before checking harness, check intermediate connectors A-13 and B-212, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 8 .

Repair the damaged harness wire.

STEP 8. Connector check: A-08 engine-ECU connector

Q. Is the check result normal?

Go to Step 9 .

Repair or replace the connector.

STEP 9. Check harness between A-101 (terminal No. 2) No. 1 injector connector and A-08 (terminal No. 8) engine-ECU connector.

Check earthing line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 10 .

Repair the damaged harness wire.

STEP 10. Perform signal wave pattern measurement at A-08 engine-ECU connector (Using an oscilloscope).

Disconnect engine-ECU connector, and connect special tool power plant ECU check harness (MB991987), and then measure the voltage on the check connector.
Engine: Idling
Transmission: Neutral
Voltage between terminal No. 8 and earth.

OK: Waveforms should be display on Inspection procedure using an oscilloscope (Refer to ).

Q. Is the check result normal?

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

Replace the engine-ECU then perform the variant coding (Refer to GROUP 00 - Precautions Before Service - How to Perform Variant Coding