Code No. P1223: Communication Line System with The Throttle Valve Controller

FUNCTION

The engine-ECU <M/T> or engine-A/T-ECU <A/T> checks whether the communication to the throttle valve controller is normal.

TROUBLE JUDGMENT

Check Conditions

Battery voltage is 6.3 V or more.
Not the communication error is from the throttle valve controller to the engine-ECU <M/T> or engine-A/T-ECU <A/T>.

Judgment Criterion

The communication error is from the engine-ECU <M/T> or engine-A/T-ECU <A/T> to the throttle valve controller.

Check Conditions

Battery voltage is 6.3 V or more.
During not the engine cranking

Judgment Criterion

The communication error is from the throttle valve controller to the engine-ECU <M/T> or engine-A/T-ECU <A/T>.

PROBABLE CAUSE

Failed engine-ECU <M/T>
Failed engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?

	Replace engine-ECU <M/T> or engine-A/T-ECU <A/T>.

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