DTC Troubleshooting: A
DTC indicator A:
 Heater Control Unit Internal Error
NOTE: Check the battery condition and the charging system, R20A3 engine model, or K24Z3 engine model.
  1. Turn the ignition switch to LOCK (0), and then to ON (II).
  1. Do the self-diagnostic function with the heater control.
  1. Check for DTCs.
Is DTC A indicated?
YES -
The heater control unit is faulty; replace the heater control unit .■
NO -
Intermittent failure; the heater control unit is OK at this time.■