AIR CONDITIONING SYSTEM, Diagnostic DTC:B1492/92

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 control 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.

WIRING DIAGRAM

PROCEDURE

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

   

   *1	Front view of wire harness connector: (to Infrared Ray Sensor)
   *2	Rear view of wire harness connector: (to Air Conditioning Amplifier)

   
   

   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 (LIN) - L76-28 (LIN1) Always Below 1 Ω X13-3 (LIN) - Body ground Always 10 kΩ or higher L76-28 (LIN1) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

2. REPLACE INFRARED RAY SENSOR

   
   

   1. Replace the infrared ray sensor with a new or properly functioning one Click here.

   2. Operate the infrared ray sensor to check that it functions properly.

      Result

      Result	Proceed to
      Infrared ray sensor malfunctions	A
      Infrared ray sensor functions properly	B

   
   

   A

   REPLACE AIR CONDITIONING AMPLIFIER Click here

   B

   END (INFRARED RAY SENSOR IS FAULTY)