B1468

AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1468/68: Rear Passenger Side Room Temperature Sensor Circuit
B1468/68 - Rear Passenger Side Room Temperature Sensor Circuit

DESCRIPTION

The rear room temperature sensor RH is installed in the rear door trim board RH to detect the rear room temperature and control the heater and air conditioner "AUTO" mode. The resistance of the rear room temperature sensor changes in accordance with the rear room temperature for RH seat. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The rear door ECU RH sends the read signal to the air conditioning amplifier via the CAN communication line. The rear door ECU RH applies voltage (5 V) to the rear room temperature sensor and reads voltage changes as the resistance of the rear room temperature sensor changes. This sensor also sends the appropriate signals to the rear door ECU RH.

HINT
This circuit uses the CAN communication line. Before performing the inspection, check that the CAN communication system is functioning normally.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (REAR ROOM TEMPERATURE SENSOR (for RH))

(a) Use the Data List to check if the rear room temperature sensor (for RH seat) is functioning properly.

Air Conditioner





OK:

The display is as specified in the normal condition.

NG -- INSPECT REAR ROOM TEMPERATURE SENSOR RH

OK -- REPLACE AIR CONDITIONING AMPLIFIER Removal

2. INSPECT REAR ROOM TEMPERATURE SENSOR RH





(a) Remove the rear room temperature sensor RH Removal.

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

Standard resistance:





NOTICE:
Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.

HINT
As the temperature increases, the resistance decreases (see the graph).

NG -- REPLACE REAR ROOM TEMPERATURE SENSOR RH Removal
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (REAR ROOM TEMPERATURE SENSOR RH - REAR DOOR ECU RH)





(a) Disconnect the Q4 rear room temperature sensor RH connector.

(b) Disconnect the O2 rear door ECU RH connector.

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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE REAR DOOR ECU RH Removal and Replacement