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
).