AIR CONDITIONING SYSTEM, Diagnostic DTC:B1492/92

DTC Code DTC Name
B1492/92 Infrared Ray Sensor Communication Malfunction

DESCRIPTION

This circuit consists of the infrared ray sensor and the air conditioning amplifier. The infrared ray sensor, which is installed on the rear roof, detects human body temperature and controls the heater and air conditioner "AUTO" mode in 4 zones. Signals are transmitted to the air conditioning amplifier via the LIN communication line. This DTC is output when communication between the infrared ray sensor and the air conditioning amplifier stops for 10 seconds or more. If the LIN communication system malfunctions, the air conditioning amplifier does not operate even if the infrared ray sensor is normal.

DTC Code DTC Detection Condition Trouble Area
B1492/92 Open in LIN communication line

  • Infrared ray sensor

  • Harness or connector between infrared ray sensor and air conditioning amplifier

  • LIN communication line

WIRING DIAGRAM

A01GZ68E18

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (INFRARED RAY SENSOR - AIR CONDITIONING AMPLIFIER)

    A01H0A9E02

    1. Disconnect the X13 infrared ray sensor 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
      X13-3 (LIN1) - L76-28 (LIN1) Always Below 1 Ω
      X13-3 (LIN1) - Body ground Always 10 kΩ or higher
      L76-28 (LIN1) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. REPLACE INFRARED RAY SENSOR


    1. Replace the infrared ray sensor with a normal one Click here.


    NEXT

  3. RECHECK DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1492 is not output.

    NG

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    OK

    END (INFRARED RAY SENSOR IS DEFECTIVE)