DTC P0606: Engine-ECU Main Processor Malfunction

OPERATION

Refer to Inspection Procedure 21: Engine-ECU Power Supply, Engine Control Relay, Ignition Switch-IG1 System

FUNCTION

System LSI checks the engine-ECU for abnormal conditions.

TROUBLE JUDGMENT

Check Condition

Ignition switch is "ON" position.

Judgement Criteria

No surveillance pulse signals is input for 0.5 second.

PROBABLE CAUSE

Failed the engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check battery.

Battery check (Refer to GROUP 54A - Battery - On-vehicle Service - Battery Test ).

Q. Is the check result normal?

	Go to Step 2 .

	Replace the battery.

STEP 2. Connector check: A-09 engine-ECU connector

Q. Is the check result normal?

Go to Step 3 .

Repair or replace the connector.

STEP 3. Perform voltage measurement at A-09 engine-ECU connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 122 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 5 .

Go to Step 4 .

STEP 4. Connector check: B-240 ignition switch connector

Q. Is the check result normal?

Check signal line for open/short circuit.

Repair or replace the connector.

STEP 5. Connector check: B-240 ignition switch connector

Q. Is the check result normal?

Go to Step 6 .

Repair or replace the connector.

STEP 6. Check harness between B-240 (terminal No. 2) ignition switch connector and A-09 (terminal No. 122) engine-ECU connector.

note

Before checking harness, check intermediate connectors B-210 and B-229, and repair if necessary.

Check signal line for damage.

Q. Is the check result normal?

Go to Step 7 .

Repair the damaged harness wire.

STEP 7. Connector check: B-206 engine control relay connector

Q. Is the check result normal?

Go to Step 8 .

Repair or replace the connector.

STEP 8. Check engine control relay itself.

Check engine control relay itself (Refer to ).

Q. Is the check result normal?

	Go to Step 9 .

	Replace the engine control relay.

STEP 9. Check harness between B-206 (terminal No. 2) engine control relay connector and A-09 (terminal No. 107) engine-ECU connector.

Check signal line for short circuit.

Q. Is the check result normal?

Go to Step 10 .

Repair the damaged harness wire.

STEP 10. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is 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 ).