DTC Troubleshooting: B1230 (F and AUTO)
DTC B1230 or DTC indicator F and AUTO:
 A Short in the Sunlight Sensor Circuit
  1. Clear the DTC with the HDS.
  1. Turn the ignition switch to LOCK (0) and then to ON (II).
  1. Do the self-diagnostic function with the HDS or the heater control unit.
  1. Check for DTCs.
Is DTC B1230 or F and AUTO indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure.■
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the sunlight sensor 2P connector.
  1. Disconnect heater control unit connectors A (28P) and B (12P).
  1. Check for continuity between heater control unit connector A (28P) No. 25 terminal and body ground.
Is there continuity?
YES -
Repair short to body ground in the wire between the heater control unit and the sunlight sensor.■
NO -
Go to Step 9 .