Inspection Procedure

HINT:

In case of using the LEXUS hand-held tester, start the inspection from step 1 and in case of not using the LEXUS hand-held tester, start from step  2.

1. Check air inlet damper position using LEXUS hand-held tester. 

   PREPARATION: 

   Connect the LEXUS hand-held tester to the DLC3.

   CHECK: 

   Check the current position of air inlet damper and the target position of air inlet damper.

   OK: 

   The current position and target position are almost similar. 

   1. OK : Check and replace A/C ECU. 
   2. NG : Go to next step. 
2. Check voltage between terminals TPI and SG of A/C ECU connector. 

   PREPARATION: 

   Remove A/C ECU with connectors still connected.

   CHECK: 

   1. Turn ignition switch to ON.
   2. Press REC/FRS switch to change air inlet between fresh and recirculation air, and measure voltage between terminals TPI and SG of A/C ECU when the air inlet damper control servomotor operates.

   OK: 

   VOLTAGE CONDITION SPECIFICATION
   
   

   FRS-REC Switch	Voltage
   REC	3.5 - 4.5 V
   FRS	0.5 - 1.5 V

   Fig 1: Identifying Terminals TPI And SG Of A/C ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT:

   As the air inlet damper control servomotor is moved form REC side to FRS side, the voltage decreases.

   1. NG : Go to step 3. 
   2. OK : Proceed to next circuit inspection shown on problem symptoms table (See  PROBLEM SYMPTOMS TABLE  ). However, if DTC B1432/32 or B1442/42 is displayed, check and replace A/C ECU. 
3. Check air inlet damper position sensor. 

   PREPARATION: 

   Remove air inlet servomotor (See BLOWER UNIT ).

   CHECK: 

   Measure resistance between terminals 1 and 2 of air inlet damper control servomotor assembly connector.

   OK: 

   Resistance: 4.2 - 7.8 kΩ 

   CHECK: 

   While operating air inlet damper control servomotor, follow the procedure in DTC B1442/42 AIR INLET DAMPER CONTROL SERVOMOTOR CIRCUIT  and measure resistance between terminals 2 and 3 of air inlet damper control servomotor assembly connector.

   Fig 2: Identifying Air Inlet Damper Position Sensor Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: 

   DAMPER POSITION RESISTANCE SPECIFICATION
   
   

   Damper Position	Resistance
   REC side	3.4 - 6.2 kΩ.
   FRS side	0.8 - 1.6 kΩ

   HINT:

   As the air inlet damper control servomotor moves from REC side to FRS side, the resistance decreases.

   1. NG : Replace air inlet damper control servomotor. 
   2. OK : Go to next step. 
4. Check harness and connectors between A/C ECU and air inlet damper control servomotor assembly (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.