Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000ZPDB
Model Year Start: 2017 Model: Sienna Prod Date Range: [08/2016 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: Rear Blower Motor Circuit; 2017 - 2020 MY Sienna [08/2016 -        ]

Rear Blower Motor Circuit

DESCRIPTION

The rear blower motor is operated by signals from the air conditioning amplifier. Rear blower motor speed signals are transmitted in accordance with changes in the duty ratio.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(e) Check the operation by referring to the table below.

Air Conditioner

Tester Display

Measurement Item

Control Range

Diagnostic Note

Blower Motor Level (Rear)

Rear blower motor

Min.: 0

Max.: 31

-

OK:

Rear blower motor operates and rear blower motor speed level changes.

Result

Result

Proceed to

NG (Rear blower motor does not operate)

A

NG (Rear blower motor operates but does not change speed)

B

OK

C
B

GO TO STEP 9

C

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

A

2.

INSPECT REAR BLOWER W/FAN MOTOR SUB-ASSEMBLY

(a) Disconnect the rear blower motor connector.

*a

Component without harness connected

(Rear Blower Motor)

(b) Connect a battery positive (+) lead to terminal 2 and a negative (-) lead to terminal 1, then check that the rear blower motor operates smoothly.

OK:

The rear blower motor operates smoothly.

NG

REPLACE REAR BLOWER MOTOR

OK

3.

CHECK HARNESS AND CONNECTOR (REAR BLOWER CONTROLLER - BODY GROUND)

(a) Disconnect the rear blower controller connector.

*a

Front view of wire harness connector

(to Rear Blower Controller)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

L24-6 (GND) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (REAR BLOWER CONTROLLER - BATTERY)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

L24-1 (+B) - Body ground

Always

11 to 14 V

*a

Front view of wire harness connector

(to Rear Blower Controller)
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

CHECK HARNESS AND CONNECTOR (REAR BLOWER CONTROLLER - REAR BLOWER MOTOR)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

L24-2 (VM) - L25-2

Always

Below 1 Ω

L24-2 (VM) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

6.

CHECK HARNESS AND CONNECTOR (REAR BLOWER MOTOR - BODY GROUND)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

L25-1 - Body ground

Always

Below 1 Ω

*a

Front view of wire harness connector

(to Rear Blower Motor)
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

7.

CHECK HARNESS AND CONNECTOR (REAR BLOWER CONTROLLER - A/C AMPLIFIER)

(a) Disconnect the D186 air conditioning amplifier connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

D186-26 (BLWH) - L24-3 (SI)

Always

Below 1 Ω

D186-26 (BLWH) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

8.

INSPECT REAR BLOWER CONTROLLER

(a) Reconnect the rear blower controller connector.

*a

Front view of wire harness connector

(to Air Conditioning Amplifier)

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

D186-26 (BLWH) - Body ground

Always

4.5 to 7.0 V
NG

REPLACE REAR BLOWER CONTROLLER

OK

9.

INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Reconnect the air conditioning amplifier connector.

(b) Remove the air conditioning amplifier with the connectors still connected.

*a

Component with harness connected

(Air Conditioning Amplifier)

(c) Measure the waveform between terminal D186-26 (BLWH) of the air conditioning amplifier and body ground.

Item

Content

Tool Setting

1 V/DIV., 500 μsec./DIV.

Condition

Ignition switch ON

Blower switch: LO

OK:

Waveform is as shown in the illustration.

HINT:

The waveform varies with the blower level.

OK

REPLACE REAR BLOWER CONTROLLER

NG

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY