Code No. P1243: Inquiry/Response Error


FUNCTION



  • Monitors the computation function of the engine-ECU.

TROUBLE JUDGMENT


Check Condition
  • Ignition switch is "ON" position.
Judgement Criterion
  • Engine-ECU can not calculate input data.

FAIL-SAFE AND BACKUP FUNCTION



  • Microcomputer is reset.

PROBABLE CAUSE



  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. 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 ).