AIR CONDITIONING SYSTEM, Diagnostic DTC:B1494/94

DTC Code DTC Name
B1494/94 Rear Emission Servo Motor Circuit

DESCRIPTION

The rear exhaust mode damper servo (for emission) sends pulse signals to inform the air conditioning amplifier of the damper position. The air conditioning amplifier activates the motor (normal or reverse) based on these signals to move the rear exhaust mode damper to the appropriate position, which controls the rear exhaust modes.

Tech Tips

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

DTC No. DTC Detection Condition Trouble Area
B1494/94 Rear exhaust mode damper position (for emission) does not change even if air conditioning amplifier operates rear exhaust mode damper servo motor

  • Rear exhaust mode damper servo motor (for emission)

  • Rear air conditioning harness

  • Harness and connector between rear air conditioning harness and air conditioning amplifier

  • Air conditioning amplifier

WIRING DIAGRAM

A01GJBNE03

INSPECTION PROCEDURE

Note


  • If this DTC is output, perform the following procedures before beginning the INSPECTION PROCEDURE.


    1. Turn the engine switch off, and wait approximately 90 seconds.

    2. Turn the engine switch on (IG).

    3. Clear DTCs Click here.

    4. Check for DTCs Click here. If this DTC is not output, there is no malfunction. If this DTC is output, perform the INSPECTION PROCEDURE below.

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B1494/94 is not output A
      DTC B1494/94 is output B
      DTC B1494/94 and B1497/97 are output C

    B

    READ VALUE USING INTELLIGENT TESTER (REAR EXHAUST MODE SERVO MOTOR TARGET PULSE (for Emission)) Click here

    C

    GO TO DTC B1497/97 Click here

    A

    USE SIMULATION METHOD TO CHECK Click here

  2. READ VALUE USING INTELLIGENT TESTER (REAR EXHAUST MODE SERVO MOTOR TARGET PULSE (for Emission))


    1. Use the Data List to check if the servo motor is functioning properly.

      Air Conditioner
      Tester Display Measurement Item / Range Normal Condition Diagnostic Note
      Emission Target Pulse (R)

      Rear exhaust mode servo motor target pulse (for emission)/

      Min.: 0, Max.: 255

      		 Customized value will be displayed -
      OK
      The display is as specified in the normal condition.

    2. Visually inspect the Rear exhaust mode servo motor (for emission).


      1. Visually inspect whether the Rear exhaust mode servo motor (for emission) operates.

        OK
        The Rear exhaust mode servo motor (for emission) operates.
        Result
        Result Proceed to
        The Data List value changes and the rear exhaust mode servo motor (for emission) operates (When troubleshooting according to the DTC output) A
        The Data List value changes and the rear exhaust mode servo motor (for emission) operates (When troubleshooting according to Problem Symptoms Table) B
        The Data List value does not change and the rear exhaust mode servo motor (for emission) does not operate C
        The Data List value changes, but the rear exhaust mode servo motor (for emission) does not operate D

    B

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    D

    CHECK HARNESS AND CONNECTOR (REAR AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER) Click here

    A

  3. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1494/94 is not output.

    NG

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  4. CHECK HARNESS AND CONNECTOR (REAR AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER)

    A01GL01E01

    1. Disconnect the S28 rear air conditioning harness connector.

    2. Disconnect the L76 air conditioning amplifier connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      S28-6 (BRRG) - L76-12 (BRRG) Always Below 1 Ω
      S28-7 (BURR) - L76-13 (BURR) Always Below 1 Ω
      S28-8 (BRRB) - L76-14 (BRRB) Always Below 1 Ω
      L76-12 (BRRG) - Body ground Always 10 kΩ or higher
      L76-13 (BURR) - Body ground Always 10 kΩ or higher
      L76-14 (BRRB) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK REAR EXHAUST MODE SERVO MOTOR (for Emission)


    1. Replace the rear exhaust mode damper servo motor Click here.

      Tech Tips

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

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1494/94 is not output.

    NG

    CHECK REAR AIR CONDITIONING HARNESS Click here

    OK

    END (REAR EXHAUST MODE SERVO MOTOR [for Emission4] IS FAULTY)

  6. CHECK REAR AIR CONDITIONING HARNESS


    1. Replace the rear air conditioning harness Click here.

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1494/94 is not output.

    NG

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    OK

    END (REAR AIR CONDITIONING HARNESS IS FAULTY)