DTC Troubleshooting: B1230 (F)
DTC B1230 or DTC indicator F:
 A Short in the Sunlight Sensor Circuit
  1. Clear the DTC with the HDS.
  1. Turn the ignition switch OFF and then ON (II).
  1. Check for DTCs.
Is DTC B1230 or F indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure.■
  1. Turn the ignition switch OFF.
  1. Disconnect the sunlight sensor 2P connector.
  1. Disconnect the heater control unit 32P connector.
  1. Check for continuity between body ground and the heater control unit 32P connector terminal No. 15.
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 .
  1. Check for continuity between the heater control unit 32P connector terminals No. 15 and No. 24.
Is there continuity?
YES -
Repair short in the wires between the heater control unit and the sunlight sensor.■
NO -
Go to Step 10 .
  1. Reconnect the sunlight sensor 2P connector.
  1. Reconnect the heater control unit 32P connector.
Is the sunlight sensor OK?
YES -
Substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original heater control unit .■
NO -