Detect The Root Cause: Notes

Identify the root cause using the created diagnosis sheet.

Identifying the root cause 

• Draw a line on the diagnosis sheet to indicate the possible cause. Narrow the search.
  NOTE:

  • Color-code when drawing lines.
  • Do not draw a line onto a existing line.
• Drawing a line is not necessary if the circuit is shorted. Refer to "PRESENT ERROR - SHORT CIRCUIT - ", "Past Error - Short Circuit -".

  Refer to the following for details of the trouble diagnosis procedure.

• "Present Error - Open Circuit -"
• "PRESENT ERROR - SHORT CIRCUIT - "
• "Past Error - Open Circuit -"
• "Past Error - Short Circuit -"
  NOTE: When the root cause appears to be a branch line or short circuit, be sure to check the control unit as well as the communication line.