Inspection Procedure

WARNING: This page is about a different car, the 2007 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

CHECK AIR CONDITIONING AMPLIFIER

Remove the A/C amplifier with the connectors still connected.
Turn the ignition switch ON.

Change the set temperature to activate the front air mix servomotor, and measure the voltage between terminals FRTP (A46-5) and FRSG (A46-18) of the A/C amplifier connector every time the set temperature is changed.

Standard voltage

STANDARD VOLTAGE REFERENCE

Set Temperature	Specified Condition
Max. cool	3.5 to 4.5 V
Max. hot	0.5 to 1.5 V

Fig 1: Checking Air Conditioning Amplifier

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

As the set temperature increases, the voltage decreases.
However, if DTC 31 or 41 is displayed, check and replace A/C amplifier.

OK: REPLACE AIR CONDITIONING AMPLIFIER

NG: GO TO NEXT STEP

CHECK FRONT AIR MIX DAMPER POSITION SENSOR

Remove the front air mix servomotor.
Measure the resistance between terminals PT (4) and GND (6) of the front air mix damper control servomotor connector.
Standard resistance: 4.2 to 7.8 kΩ

While operating the front air mix servomotor, measure the resistance between terminals PT (4) and GND (6) of the front air mix damper control servomotor connector.

Standard resistance

STANDARD RESISTANCE REFERENCE

Position	Standard Condition
Max. COOL	3.6 to 6.8 kΩ
Max. WARM	0.5 to 1.1 kΩ

HINT:

As the front air mix servomotor moves from cool side to warm side, the resistance decreases.

NG: REPLACE FRONT AIR MIX SERVOMOTOR

Fig 2: Checking Front Air Mix Damper Position Sensor

OK: GO TO NEXT STEP

CHECK WIRE HARNESS (FRONT AIR MIX DAMPER POSITION SENSOR - AIR CONDITIONING AMPLIFIER)
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: REPLACE AIR CONDITIONING AMPLIFIER