Code No. P0204: No. 4 Injector System

OPERATION

Power is supplied to the injector (terminal No. 1) from the engine control relay (terminal No. 1).
The engine-ECU <M/T> or engine-A/T-ECU <A/T> (terminal No. 21) makes the power transistor in the unit be in ON position, and that makes currents go on the injector (terminal No. 2).

FUNCTION

The engine-ECU <M/T> or engine-A/T-ECU <A/T> controls the power supply interval of the injector.
The fuel injection amount of the injector depends on the power supply interval.

TROUBLE JUDGMENT

Check Condition

While engine is running.

Judgment Criterion

Injector coil surge voltage has not been detected for 2 seconds.

PROBABLE CAUSES

Failed No. 4 injector
Open/short circuit in injector circuit or loose connector contact
Failed engine-ECU <M/T> or engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

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

Item 04: No. 4 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: B-105 No. 4 injector connector

Q. Is the check result normal?

	Go to Step 3 .

	Repair or replace the connector.

STEP 3. Check No. 4 injector itself.

Check No. 4 Injector itself (Refer to ).

Q. Is the check result normal?

	Go to Step 4 .

	Replace the No. 4 injector.

STEP 4. Perform voltage measurement at B-105 No. 4 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-15X engine control relay connector

Q. Is the check result normal?

	Check intermediate connector B-45, and repair if necessary. If intermediate connector is normal, check and repair harness between B-15X (terminal No. 1) engine control relay connector and B-105 (terminal No. 1) No. 4 injector connector. Check power supply line for open/short circuit.

	Repair or replace the connector.

STEP 6. Connector check: B-15X 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-15X (terminal No. 1) engine control relay connector and B-105 (terminal No. 1) No. 4 injector connector.

note

Before checking harness, check intermediate connector B-45, 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: D-243 engine-ECU <M/T> connector or D-212 engine-A/T-ECU <A/T> connector

Q. Is the check result normal?

	Go to Step 9 .

	Repair or replace the connector.

STEP 9. Check harness between B-105 (terminal No. 2) No. 4 injector connector and D-243 (terminal No. 21) engine-ECU <M/T> connector or D-212 (terminal No. 21) engine-A/T-ECU <A/T> connector.

note

Before checking harness, check intermediate connector B-45, and repair if necessary.

Check output 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 D-243 engine-ECU <M/T> connector or D-212 engine-A/T-ECU <A/T> connector (Using an oscilloscope).

Engine: Idling
Transmission: Neutral <M/T> or P range <A/T>
Voltage between terminal No. 21 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 <M/T> or engine-A/T-ECU <A/T>.