AIR CONDITIONING SYSTEM, Diagnostic DTC:B1448/48

DTC Code DTC Name
B1448/48 Passenger Side FACE Servo Motor Circuit

DESCRIPTION

The No. 5 air conditioning radiator damper servo sub-assembly*1 or No. 6 air conditioning radiator damper servo sub-assembly*2 sends pulse signals to indicate the damper position to the air conditioning amplifier assembly. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the No. 5 air conditioning radiator damper servo sub-assembly*1 or No. 6 air conditioning radiator damper servo sub-assembly*2 to any position, which controls the air outlet switching.

The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.


DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B1448/48 Passenger Side FACE Servo Motor Circuit Front passenger side air mix damper position does not change even if air conditioning amplifier assembly operates No. 5 air conditioning radiator damper servo sub-assembly*1 or No. 6 air conditioning radiator damper servo sub-assembly*2

  • No. 5 air conditioning radiator damper servo sub-assembly*1

  • No. 6 air conditioning radiator damper servo sub-assembly*2

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

Memorized

(30 seconds or more)

Tech Tips

The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.

WIRING DIAGRAM

B002CUIE06

CAUTION / NOTICE / HINT

Note

Before disconnecting the cable from the negative (-) battery terminal or replacing the air conditioning amplifier assembly, record the last operation state of the air conditioning for each transmitter. After replacement, it is necessary to perform memory registration for each transmitter.

Click here

Tech Tips

Confirm that no mechanical problem is present because this DTC can be output when either a damper link or damper is mechanically locked.

PROCEDURE


  1. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Data List.

    5. Check the value(s) by referring to the table below.


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Air Outlet Servo Targ Pulse(P) No. 5 air conditioning radiator damper servo sub-assembly target pulse*2 or No. 6 air conditioning radiator damper servo sub-assembly target pulse*1

      Min.: 128

      Max.: 383

      for LHD with rear control switch


      • FACE1: 258 (pulse)

      • FACE2: 267 (pulse)

      • FACE: 282 (pulse)

      • B/L: 295 (pulse)

      • B/L2: 303 (pulse)

      • FOOT-0 (for save energy and airflow control function): 329 (pulse)

      • FOOT-0 (except save energy and airflow control function): 313 (pulse)

      • FOOT-D: 313 (pulse)

      • FOOT-R (for save energy and airflow control function): 329 (pulse)

      • FOOT-R (except save energy and airflow control function): 313 to 321 (pulse)

      • FOOT-F (manual mode and for save energy and airflow control function): 329 (pulse)

      • FOOT-F (manual mode and except save energy and airflow control function): 313 (pulse)

      • FOOT-F (automatic mode): 329 (pulse)

      • FOOT/DEF: 344 (pulse)

      • DEF: 372 (pulse)

      for RHD with rear control switch


      • FACE1: 254 (pulse)

      • FACE2: 245 (pulse)

      • FACE: 230 (pulse)

      • B/L: 217 (pulse)

      • B/L2: 209 (pulse)

      • FOOT-0 (for save energy and airflow control function): 183 (pulse)

      • FOOT-0 (except save energy and airflow control function): 199 (pulse)

      • FOOT-D: 199 (pulse)

      • FOOT-R (for save energy and airflow control function): 183 (pulse)

      • FOOT-R (except save energy and airflow control function): 191 to 199 (pulse)

      • FOOT-F (manual mode and for save energy and airflow control function): 183 (pulse)

      • FOOT-F (manual mode and except save energy and airflow control function): 199 (pulse)

      • FOOT-F (automatic mode): 183 (pulse)

      • FOOT/DEF: 168 (pulse)

      • DEF: 140 (pulse)

      		 -
      Air Outlet Servo Actu Pulse(P) No. 5 air conditioning radiator damper servo sub-assembly actual pulse*2 or No. 6 air conditioning radiator damper servo sub-assembly actual pulse*1

      Min.: 128

      Max.: 383

      for LHD with rear control switch


      • FACE1: 258 (pulse)

      • FACE2: 267 (pulse)

      • FACE: 282 (pulse)

      • B/L: 295 (pulse)

      • B/L2: 303 (pulse)

      • FOOT-0 (for save energy and airflow control function): 329 (pulse)

      • FOOT-0 (except save energy and airflow control function): 313 (pulse)

      • FOOT-D: 313 (pulse)

      • FOOT-R (for save energy and airflow control function): 329 (pulse)

      • FOOT-R (except save energy and airflow control function): 313 to 321 (pulse)

      • FOOT-F (manual mode and for save energy and airflow control function): 329 (pulse)

      • FOOT-F (manual mode and except save energy and airflow control function): 313 (pulse)

      • FOOT-F (automatic mode): 329 (pulse)

      • FOOT/DEF: 344 (pulse)

      • DEF: 372 (pulse)

      for RHD with rear control switch


      • FACE1: 254 (pulse)

      • FACE2: 245 (pulse)

      • FACE: 230 (pulse)

      • B/L: 217 (pulse)

      • B/L2: 209 (pulse)

      • FOOT-0 (for save energy and airflow control function): 183 (pulse)

      • FOOT-0 (except save energy and airflow control function): 199 (pulse)

      • FOOT-D: 199 (pulse)

      • FOOT-R (for save energy and airflow control function): 183 (pulse)

      • FOOT-R (except save energy and airflow control function): 191 to 199 (pulse)

      • FOOT-F (manual mode and for save energy and airflow control function): 183 (pulse)

      • FOOT-F (manual mode and except save energy and airflow control function): 199 (pulse)

      • FOOT-F (automatic mode): 183 (pulse)

      • FOOT/DEF: 168 (pulse)

      • DEF: 140 (pulse)

      		 -

      • *1: for RHD with Rear Control Switch

      • *2: for LHD with Rear Control Switch


      Body Electrical > Air Conditioner > Data List
      Tester Display
      Air Outlet Servo Targ Pulse(P)
      Air Outlet Servo Actu Pulse(P)
      OK
      The display is as specified in the Normal Condition column.
      Result
      Result Proceed to
      Target pulse changes but actual pulse does not change A
      Target pulse and actual pulse do not change B
      Actual pulse changes following the target pulse (When troubleshooting according to the DTC) C
      Actual pulse changes following the target pulse (When troubleshooting according to Problem Symptoms Table) D

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    RECONFIRM DTC OUTPUT Click here

    D

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    A

  2. REPLACE NO. 5 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY OR NO. 6 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY


    1. Replace the No. 5 air conditioning radiator damper servo sub-assembly*1 or No. 6 air conditioning radiator damper servo sub-assembly*2 with a new or normally functioning one.

      Click here

      Tech Tips

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or known good one and check that the condition returns to normal.


      • *1: for LHD

      • *2: for RHD

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1448/48 is output A
      DTC B1448/48 is not output (for LHD) B
      DTC B1448/48 is not output (for RHD) C

    B

    END (NO. 5 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY WAS DEFECTIVE)

    C

    END (NO. 6 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY WAS DEFECTIVE)

    A

  3. REPLACE AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the air conditioning harness assembly.

      Click here

      Tech Tips

      Since the air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning harness assembly with a new or known good one and check that the condition returns to normal.

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1448/48 is output A
      DTC B1448/48 is not output B

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    B

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

  4. RECONFIRM DTC OUTPUT


    1. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1448/48 is output A
      DTC B1448/48 is not output B

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    B

    USE SIMULATION METHOD TO CHECK Click here