Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

Actuator check.

PREPARATION:

Warm up engine.
Set to the actuator check mode (See PRE-CHECK ).
Press the UP switch and change it to step operation.

CHECK:

Press the UP temperature control switch and check the operation of the air mix damper and the condition of the blower.

OK:

Air Mix Damper condition

Display Code	Air Mix Damper	Condition
0 - 3 4 - 6 7 - 9	0 % (Fully closed) 50 % 100 % (Fully opened)	Cool air comes out - Warm air comes out

OK : Proceed to next circuit inspection shown on problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
NG : Go to next step.

Check air mix damper control step motor.
PREPARATION:

Remove air mix damper control step motor (See AIR MIX SERVOMOTOR ).

CHECK:

Measure resistance between terminals 3 and other terminals.

OK:

Resistance

Fig 1: Identifying Air Mix Damper Control Step Motor
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Terminal Resistance Specification
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG : Replace air mix damper control servomotor.
2. OK : Go to next step.
Check harness and connector between A/C ECU and air mix damper control servomotor, air mix damper control servomotor and battery, air mix damper control servomotor and body ground (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
1. NG : Repair or replace harness or connector.
2. OK : Check and replace A/C ECU.