DTC Troubleshooting: B1225 (03)
DTC B1225 or DTC indicator 03: 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 ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF 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 03 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 ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connectors.

?3.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
Climate control unit 32P connector: disconnected
In-car temperature sensor 2P connector: disconnected
Test circuit
TR
Test point 1
Climate control unit 32P connector No. 23 (LT BLU)
Test point 2
In-car temperature sensor 2P connector No. 2 (LT BLU)


Is there continuity?

     
YES
     
     
     
The TR wire is not opened. Go to step 3.
     
NO
     
     
     
Repair an open in the wire between the climate control unit and the in-car temperature sensor.?
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
IG LOCK (0) or OFF mode
Climate control unit 32P connector: disconnected
In-car temperature sensor 2P connector: disconnected
Test circuit
SENSOR COM
Test point 1
Climate control unit 32P connector No. 22 (BLU)
Test point 2
In-car temperature sensor 2P connector No. 1 (BLU)


Is there continuity?

     
YES
     
     
     
The SENSOR COM wire is OK. Go to step 4.
     
NO
     
     
     
Repair an open in the wire between the climate control unit and the in-car temperature sensor.?
4.
Shorted wire check (TR line to S 5V/S5V line):

Shorted wire check (TR line to S 5V/S5V line)
?1.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
Climate control unit 32P connector: disconnected
In-car temperature sensor 2P connector: disconnected
Test circuit
TR, S 5V
Test point 1
Climate control unit 32P connector No. 23 (LT BLU)
Test point 2
Climate control unit 32P connector No. 24 (BLK)


Is there continuity?

     
YES
     
     
     
Repair a short in the wires between the climate control unit and the in-car temperature sensor.?
     
NO
     
     
     
The TR wire and S5V/S5V wire are OK. Go to step 5.
5.
In-car temperature sensor check:

In-car temperature sensor check
?1.
Test the in-car temperature sensor.

Is the in-car temperature sensor OK?

     
YES
     
     
     
     
NO