Inspection Procedure

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

Check Voltage Between Terminal Blwc Of Integration Control And Panel Connector And Body Ground
Preparation:

Remove the integration control and panel with connector still connected.

Check:
1. Turn ignition switch to ON.
2. Operate blower motor.
3. Measure voltage between terminal BLWC of integration control and panel and body ground.
OK:

Voltage: 1 - 3 V

Fig 1: Locating Integration Control And Panel BLWC Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Go to step 3 .
2. NG: Go to next step.
Check blower motor.
Preparation:

Remove blower motor.

Check:

Connect the positive (+) lead from the battery to terminal 2 of blower motor connector and the negative (-) lead to terminal 1.

OK:

Blower motor operates smoothly.

Fig 2: Testing Blower Motor
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Replace blower motor.
2. OK: Go to next step.
Check Voltage Between Terminal Vmc Of Integration Control And Panel And Body Ground
Preparation:

Remove the integration control and panel with connector still connected.

Check:
1. Turn ignition switch to ON.
2. Operate rear A/C blower motor.
3. Measure voltage between terminal VMC of integration control and panel and body ground, when blower switch is operated to following positions.
OK:

Fig 3: A/C Blower Motor Voltage Specifications
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 4: Locating Integration Control And Panel VMC Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Proceed to next circuit inspection shown on problem symptoms table. See PROBLEM SYMPTOMS TABLE .
2. NG: Go to next step.
Check power transistor.
Preparation:

Remove power transistor POWER TRANSISTOR (FOR REAR A/C) .

Check:
1. Connect the positive (+) lead from the battery to terminal 1 through a 12 V - 3.4 W test bulb and negative (-) lead to terminal 2.
  
  Fig 5: Testing Power Transistor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the test bulb lights up when another positive (+) lead is connected to terminal 4 through a 12 V - 3.4 W test bulb.
OK:

Test bulb lights up.

Check:

Measure resistance between terminals 2 and 4.

Fig 6: Testing Power Transistor Resistance
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK:

Resistance: 2.0 - 2.4 kΩ
1. NG: Replace power transistor.
2. OK: Go to next step.
Check harness and connector between power transistor and integration control and panel, power transistor and body ground.
1. NG: Repair or replace harness or connector.
2. OK: Check and replace Integration Control And Panel. See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE