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-A/T-ECU (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-A/T-ECU connector controls the power supply interval of the injector.
The fuel injection amount of the injector depends on the power supply interval.

TROUBLE JUDGMENT

Check Conditions

Engine speed is between 50 and 1000 r/min.
Throttle position sensor (main) output is 1.15 V or less.
Injector operation (by carrying out actuator test) is not in progress.

Judgment Criteria

Injector coil surge voltage (battery positive voltage + 2 V) has not been detected for 4 seconds.

PROBABLE CAUSE

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

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 ).

	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.

STEP 3. Check No. 4 injector itself.

Check No. 4 Injector (Refer to ) itself.

Q. Is the check result normal?

	Go to Step 4 .

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

Repair or replace.

STEP 6. Connector check: B-15X engine control relay connector

Q. Is the check result normal?

Go to Step 7.

Repair or replace.

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 C-116, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 8 .

Repair.

STEP 8. Connector check: C-110 engine-A/T-ECU connector

Q. Is the check result normal?

Go to Step 9 .

Repair or replace.

STEP 9. Check harness between B-105 (terminal No. 2) No. 4 injector connector and C-110 (terminal No. 21) engine-A/T-ECU connector.

Check output line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 10 .

Repair.

STEP 10. Perform signal wave pattern measurement at C-110 engine-A/T-ECU connector (Using an oscilloscope).

Engine: Idling
Transmission: P range
Voltage between terminal No. 21 and earth.

OK: Waveform 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

Replace engine-A/T-ECU.