LIN Communication System

MULTIPLEX COMMUNICATION: LIN COMMUNICATION SYSTEM: B1492/92: Infrared Ray Sensor Communication Malfunction

DTC 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 zone. Signals are transmitted to the air conditioning amplifier via LIN communication line. This DTC is output when LIN communication between the infrared ray sensor and air conditioning amplifier stop 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





INSPECTION PROCEDURE
NOTE: When using the intelligent tester or Techstream with the power switch OFF to troubleshoot:

Connect the intelligent tester or Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the tester and vehicle begins.

PROCEDURE

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





(a) Disconnect the X13 infrared ray sensor connector.
(b) Disconnect the L76 air conditioning amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (INFRARED RAY SENSOR - BATTERY AND BODY GROUND)





(a) Disconnect the X13 infrared ray sensor connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard resistance:






Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK INFRARED RAY SENSOR (OPERATION)
(a) Replace the infrared ray sensor with a new or normally functioning one Removal.
(b) Operate the infrared ray sensor to check that it functions normally.
OK:
Infrared ray sensor function operates normally.
NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- END (INFRARED RAY SENSOR IS FAULTY)