- After repairing the trouble area, the diagnostic code that is retained in the ECU memory must be canceled out by removing the EFI (15A or 20A) fuse for thirty seconds or more, depending on the ambient temperature (the lower temperature, the longer the fuse must be left out with the ignition switch OFF.
Cancellation can also be done by removing the battery negative terminal, but keep in mind when removing the negative battery cable, the other memory systems (radio, ETR, clock, etc.) will also be canceled out.
If the diagnostic code is not canceled out, it will be retained by the ECU and appear along with a new code in event of future trouble. If it is necessary to work on engine components requiring removal of the battery terminal, a check must first be made to see if a diagnostic code is detected.
- After cancellation, perform a road test, if necessary, confirm that a normal code is now read on the CHECK ENGINE warning light or super monitor display.
- If the same diagnostic code is still indicated, it indicates that the trouble area has not been repaired thoroughly.