How to Troubleshoot the Heating
How to Use the Self-diagnostic Function without the HDS
The heater control unit has a self-diagnostic function. To run the self-diagnostic function, do the following:
  1. Turn the ignition switch OFF.
  1. Press and hold the AUTO and RECIRCULATION CONTROL buttons, turn the ignition switch ON (II), then release the AUTO and RECIRCULATION CONTROL buttons.
  1. All temperature indicator segments come on for 2 seconds, then self-diagnostic function begins.
    NOTE:
    • The blower motor can be run at various speeds regardless of what the panel is displaying.
    • If there is any problem in the system, the temperature indicator will light up the segment (A through P) and AUTO indicator corresponding to the error. The temperature indicator will then alternate every second between displaying ‘‘88'' (all segments lit) and the error code segment (A through P) and AUTO indicator. To determine the meaning of the DTC, refer to checking for DTCs.
    • If there are no problems detected, the segments will not illuminate, and the system will appear to be turned off.

Canceling the Self-diagnostic Function

  1. Turn the ignition switch OFF to cancel the self-diagnostic function. After completing repair work, run the self-diagnostic function again to make sure that there are no other DTCs.