DTC Troubleshooting: B1227 (C and AUTO)
DTC B1227 or DTC indicator C and AUTO:
 An Open in the Outside Air Temperature 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 B1227 or C and AUTO indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure; check for loose wires or poor connections on the outside air temperature sensor circuit.■
  1. Turn the ignition switch to LOCK (0).
Is the outside air temperature sensor OK?
YES -
Go to Step 7 .
NO -
Replace the outside air temperature sensor .■
  1. Disconnect heater control unit connectors A (28P) and B (12P).
  1. Check for continuity between heater control unit connector A (28P) No. 24 terminal and the outside air temperature sensor 2P connector No. 1 terminal.
Is there continuity?
YES -
Go to Step 9 .
NO -
Repair open in the wire between the heater control unit and the outside air temperature sensor.■
  1. Check for continuity between heater control unit connector B (12P) No. 10 terminal and the outside air temperature sensor 2P connector No. 2 terminal.
Is there continuity?
YES -
Check for loose wires or poor connections at heater control unit connectors A (28P), B (12P), and at the outside air temperature sensor 2P connector. If the connections are good, substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original heater control unit .■
NO -
Repair open in the wire between the heater control unit and the outside air temperature sensor.■