AIR CONDITIONING SYSTEM(for Manual Air Conditioning System), Diagnostic DTC:B1486

DTC Code DTC Name
B1486 Driver Side Air Outlet Damper Control Servo Motor Circuit

DESCRIPTION

The rear mode damper servo sub-assembly sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the rear mode damper servo sub-assembly to the appropriate 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 No. 2 air conditioning harness assembly.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B1486 Driver Side Air Outlet Damper Control Servo Motor Circuit Rear air outlet damper position sensor value does not change even if air conditioning amplifier assembly operates rear mode damper servo sub-assembly

  • Rear mode damper servo sub-assembly

  • No. 2 air conditioning harness assembly

  • Air conditioning amplifier assembly

Memorized

(30 sec. or more)*1

WIRING DIAGRAM

A002BQFE07

CAUTION / NOTICE / HINT

Tech Tips

Confirm that no mechanical problems are 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 ignition switch to ON.

    3. Turn the GTS on.

    4. Operate the rear passenger side mode switch.

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

    6. 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 Pls (F&R D) Rear mode damper servo sub-assembly target pulse

      Min.: 128

      Max.: 383

      • FACE: 83 (pulse)

      • B/L: 38 (pulse)

      • FOOT: 7 (pulse)

      		 -
      A/O Servo Actual Pulse(F&R D) Rear mode damper servo sub-assembly actual pulse

      Min.: 128

      Max.: 383

      • FACE: 83 (pulse)

      • B/L: 38 (pulse)

      • FOOT: 7 (pulse)

      		 -

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Air Outlet Servo Pls (F&R D)
      A/O Servo Actual Pulse(F&R D)
      OK
      When the rear passenger side mode switch is operated, the actual pulse changes following the target pulse.
      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. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - NO. 2 AIR CONDITIONING HARNESS ASSEMBLY)


    1. Disconnect the L20 No. 2 air conditioning harness assembly connector.

    2. Disconnect the F81 air conditioning amplifier assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      F81-27 (R BBU) - L20-4 (R BBU) Always Below 1 Ω
      F81-1 (R BUS) - L20-3 (R BUS) Always Below 1 Ω
      F81-25 (R BUG) - L20-2 (R BUG) Always Below 1 Ω
      F81-27 (R BBU) - Body ground Always 10 kΩ or higher
      F81-1 (R BUS) - Body ground Always 10 kΩ or higher
      F81-25 (R BUG) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. REPLACE REAR MODE DAMPER SERVO SUB-ASSEMBLY


    1. Replace the rear mode damper servo sub-assembly.

      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.

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1486 is output A
      DTC B1486 is not output B

    B

    END (REAR MODE DAMPER SERVO SUB-ASSEMBLY WAS DEFECTIVE)

    A

  4. REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the No. 2 air conditioning harness assembly.

      Click here

      Tech Tips

      Since the No. 2 air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the No. 2 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 B1486 is output A
      DTC B1486 is not output B

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    B

    END (NO. 2 AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

  5. RECONFIRM DTC OUTPUT


    1. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1486 is output A
      DTC B1486 is not output B

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    B

    USE SIMULATION METHOD TO CHECK Click here