Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM0000018MW004X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: AIR CONDITIONING: AIR CONDITIONING SYSTEM: 11; Room Temperature Sensor Circuit; 2007 MY LX470 [08/2006 -        ]

DTC

11

Room Temperature Sensor Circuit

DESCRIPTION

This sensor detects the temperature inside the cabin (front side) and sends the appropriate signals to the A/C amplifier.

DTC No.

Detection Item

Trouble Area

11

Open or short in front room temperature sensor circuit
  • Front room temperature sensor
  • Harness or connector between front room temperature sensor and A/C amplifier
  • A/C amplifier

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

CHECK VOLTAGE BETWEEN TERMINALS FRTR AND FRSG OF AIR CONDITIONING AMPLIFIER

(a) Remove the A/C amplifier with the connectors still connected.

(b) Turn the ignition switch ON.

(c) Measure the voltage between terminals FRTR (A48-17) and FRSG (A48-18) of A/C amplifier connector at each temperature.

Standard voltage:

1.8 to 2.2 V at 25°C (77°F)

1.2 to 1.6 V at 40°C (104°F)

HINT:

  • As the temperature increases, the voltage decreases.
  • However, if DTC11 is displayed, check and replace the A/C amplifier.
OK

REPLACE AIR CONDITIONING AMPLIFIER

NG

2.

INSPECT FRONT ROOM TEMPERATURE SENSOR

(a) Disconnect the R7 front room temperature sensor connector.

(b) Measure the resistance between terminals 1 and 2 the of front room temperature sensor connector at each temperature.

Standard resistance:

1.65 to 1.75 kΩ at 25°C (77°F)

0.55 to 0.65 kΩ at 50°C (122°F)

HINT:

As the temperature increases, the resistance decreases.
NG

REPLACE FRONT ROOM TEMPERATURE SENSOR

OK

3.

CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - FRONT ROOM TEMPERATURE SENSOR)
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

REPLACE AIR CONDITIONING AMPLIFIER