DTC Troubleshooting: B1226 (A-B2), B1226 (02)

DTC B1226 or DTC screen A-B2 or DTC indicator 02  : A short in the in-car temperature sensor circuit

DTCs (AC)

1. 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
   B1226 A short in the in-car temperature sensor circuit

   Is DTC B1226 or Error on the DTC screen A-B2 (climate control panel without display) or 02 (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. Shorted 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): 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 continuity?

   YES 

   Repair a short to ground in the TR wire.

   NO 

   The TR wire is not shorted. Go to step 3.

3. Shorted wire check (TR line to 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	Climate control unit connector A (32P) No. 27

   Is there continuity?

   YES 

   Repair a short in the TR wire to SENSOR COM wire.

   NO 

   The TR wire and SENSOR COM wire are OK. Go to step 4.

4. In-car temperature sensor check

   -1. Test the in-car temperature sensor .

   Is the in-car temperature sensor OK?

   YES 

   Replace the climate control unit .

   NO 

   Replace the in-car temperature sensor .