Inspection Procedure

WARNING: This page is about a different car, the 2005 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.

Check voltage between terminals TAM and FRSG of A/C amplifier.
PREPARATION:

Remove A/C amplifier with connectors still connected.

CHECK:
1. Turn ignition switch to ON.
2. Measure voltage between terminals TAM and FRSG of A/C amplifier connector at each temperature.
OK:
1. Voltage:
2. at 25°C (77°F): 1.35 - 1.75 V
3. at 40°C (104°F): 0.85 - 1.25 V
Fig 1: Checking Voltage Between Terminals TAM And FRSG Of A/C Amplifier
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

As the temperature increases, the voltage decreases.
1. NG: Go to step 2.
2. OK: Proceed to next circuit inspection shown on problem symptoms table (See PROBLEM SYMPTOMS TABLE ). However, if DTC 12 is displayed, check and replace A/C amplifier.
Check ambient temperature sensor.
PREPARATION:

Disconnect ambient temperature sensor connector.

CHECK:

Measure resistance between terminals 1 and 2 of ambient temperature sensor connector at each temperature.

OK:
1. Resistance :
2. at 25°C (77°F): 1.6 - 1.8 kΩ
3. at 50°C (122°F): 0.5 - 0.7 kΩ
Fig 2: Identifying Ambient Temperature Sensor Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

As the temperature increases, the resistance decreases.

NOTE: When installing the ambient temperature sensor, be sure to connect the sensor connector before connecting the battery.
1. NG: Replace ambient temperature sensor.
2. OK: Go to Next Step.
Check harness and connector between ambient temperature sensor and A/C amplifier (See PROCEDURE ).
1. NG: Repair or replace harness or connector.
2. OK: Check and replace A/C amplifier.