( TF09E8HK711000Y1230FAAT00 )
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. 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 connector.
  1. Disconnect the climate control unit 36P connector.
  1. Check for continuity between body ground and the climate control unit 36P connector No. 1 and No. 19 terminals individually.
Is there continuity?
YES -
Repair short to body ground in the wires between the climate control unit and the sunlight sensor.■
NO -
Go to Step 9 .
  1. Check for continuity between the climate control unit 36P connector No. 1 and No. 19 terminals.
Is there continuity?
YES -
Repair short in the wires between the climate control unit and the sunlight sensor.■
NO -
Go to Step 10 .
  1. Reconnect the sunlight sensor connector.
  1. Reconnect the climate control unit 36P connector.
Is the sunlight sensor OK?
YES -
Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit .■
NO -