DTC Troubleshooting: B1225 (A-B1), B1225 (01)
DTC B1225 or DTC screen A-B1 or DTC indicator 01: An open in the in-car temperature sensor circuit
DTC Description
DTC
B1225 An open in the in-car temperature sensor circuit
  

1.
Problem verification:

Problem verification
?1.
Clear the DTC with the HDS.


?2.
Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

?3.
Do the Self-Diagnostic Function with the HDS or the climate control unit.

?4.
Check for DTCs.
DTC Description
DTC
B1225 An open in the in-car temperature sensor circuit
  

Is DTC B1225 or Error on the DTC screen A-B1 (climate control panel without display) or 01 (climate control panel with display) indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.?
2.
Open wire check (TR line):

Open wire check (TR line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
Climate control unit connector A (32P)
In-car temperature sensor 2P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit connector A (32P): disconected
In-car temperature sensor 2P connector: disconnected
Test point 1
Climate control unit connector A (32P) No. 27
Test point 2
In-car temperature sensor 2P connector (female terminals) No. 2:


Is there continuity?

     
YES
     
     
     
The TR wire is not open. Go to step 3.
     
NO
     
     
     
Repair an open in the TR wire.?
3.
Open wire check (SENSOR COM line):

Open wire check (SENSOR COM line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit connector A (32P): disconnected
In-car temperature sensor 2P connector: disconnected
Test point 1
Climate control unit connector A (32P) No. 12
Test point 2
In-car temperature sensor 2P connector (female terminals) No. 1:


Is there continuity?

     
YES
     
     
     
The SENSER COM wire is OK. Go to step 4.
     
NO
     
     
     
Repair an open in the SENSOR COM wire.?
4.
Shorted wire check (TR line to power):

Shorted wire check (TR line to power)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Climate control unit connector A (32P): disconnected
In-car temperature sensor 2P connector: disconnected
Test point 1
Climate control unit connector A (32P) No. 27
Test point 2
Body ground

Is there any voltage?

     
YES
     
     
     
Repair a short to power in the TR wire.?
     
NO
     
     
     
The TR wire is OK. Go to step 5.
5.
In-car temperature sensor check:

In-car temperature sensor check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Test the in-car temperature sensor.

Is the in-car temperature sensor OK?

     
YES
     
     
     
     
NO