Toyota CH-R Service Manual: Blower Motor Circuit

DESCRIPTION

The blower motor with fan sub-assembly is operated by signals from the air conditioning amplifier assembly through the blower resistor. Blower motor speed signals are transmitted in accordance with changes in the duty ratio. The blower motor speed becomes slower when the duty interval is wider, and the blower motor speed becomes faster when the duty interval is narrower.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.	PERFORM ACTIVE TEST USING TECHSTREAM (BLOWER MOTOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch ON.

(c) Turn the Techstream on.

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

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Blower Motor	Blower motor with fan sub-assembly	Min.: 0 Max.: 100	Operates between 0 to 100 %

Body Electrical > Air Conditioner > Active Test

Tester Display
Blower Motor

Result	Proceed to
OK	A
NG (Blower motor with fan sub-assembly does not operate)	B
NG (Blower motor with fan sub-assembly operates but does not change speed)	C

A

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

C

GO TO STEP 6

B

2.	CHECK HARNESS AND CONNECTOR (AIR CONDITIONING HARNESS ASSEMBLY (BLOWER ASSEMBLY) - POWER SOURCE)

(a) Disconnect the air conditioning harness assembly (blower assembly) connector.

*a Front view of wire harness connector (to Air Conditioning Harness Assembly (Blower Assembly))

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A83-1 - A83-2	Always	11 to 14 V

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A83-1 - Body ground	Always	Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.	INSPECT AIR CONDITIONING HARNESS ASSEMBLY (BLOWER ASSEMBLY)

(a) Remove the air conditioning harness assembly (blower assembly).

Click here

(b) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition A83-2 - F7b-3 (+B) Always Below 1 Ω A-1 - F7b-2 (+) Always Below 1 Ω A-2 - F7b-1 (-) Always Below 1 Ω A83-1 - F7b-6 (GND) Always Below 1 Ω w-7 - F7b-5 (SI) Always Below 1 Ω A83-2 or F7b-3 (+B) - Body ground Always 10 kΩ or higher A-1 or F7b-2 (+) - Body ground Always 10 kΩ or higher A-2 - F7b-1 (-) - Body ground Always 10 kΩ or higher A83-1 - F7b-6 (GND) - Body ground Always 10 kΩ or higher w-7 - F7b-5 (SI) - Body ground Always 10 kΩ or higher

*a Front view of wire harness connector (to Air Conditioning Harness Assembly (Blower Assembly) *b Front view of wire harness connector (to Blower Motor with Fan Sub-assembly) *c Front view of wire harness connector (to Blower Resistor) *d Front view of wire harness connector (to Air Conditioning Harness Assembly (Heater Radiator Unit Sub-assembly))

NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY (BLOWER ASSEMBLY)

OK

4.	INSPECT AIR CONDITIONING HARNESS ASSEMBLY (HEATER RADIATOR UNIT SUB-ASSEMBLY)

(a) Remove the air conditioning harness assembly (heater radiator unit sub-assembly).

Click here

(b) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition w-7 - F7A-40 (BLW) Always Below 1 Ω w-7 - F7A-40 (BLW) - Body ground Always 10 kΩ or higher

*a Front view of wire harness connector (to Air Conditioning Amplifier Assembly) *b Front view of wire harness connector (to Air Conditioning Harness Assembly (blower assembly))

NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY (HEATER RADIATOR UNIT SUB-ASSEMBLY)

OK

5.	INSPECT BLOWER RESISTOR

(a) Reconnect the F7b blower resistor connector.

(b) Reconnect the w air conditioning harness assembly (blower assembly) connector.

(c) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Switch Condition Specified Condition F7A-40 (BLW) - Body ground Ignition switch ON Blower switch: Lo 11 to 14 V

*a Front view of wire harness connector (to Air Conditioning Amplifier Assembly)

NG

REPLACE BLOWER RESISTOR

OK

6.	INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Reconnect the F72 and F7A air conditioning amplifier assembly connectors.

(b) Turn the ignition switch ON.

(c) Turn the blower switch Lo.

(d) Connect an oscilloscope to terminals F72-29 (GND) and F7A-40 (BLW) of the air conditioning amplifier assembly and check the waveform.

OK:

Waveform is similar to that shown in the illustration.

HINT:

The waveform varies with the blower speed.

Item	Content
Tool Setting	2 V/DIV., 1 ms./DIV.
Vehicle Condition	Ignition switch ON Blower switch: Lo

*a

Component with harness connected (Air Conditioning Amplifier Assembly)

-

-

NG

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

OK

7.	REPLACE BLOWER RESISTOR

(a) Replace the blower resistor with a new or known good one.

Click here

NEXT

8.	PERFORM ACTIVE TEST USING TECHSTREAM (BLOWER MOTOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch ON.

(c) Turn the Techstream on.

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

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Blower Motor	Blower motor with fan sub-assembly	Min.: 0 Max.: 100	Operates between 0 to 100 %

Body Electrical > Air Conditioner > Active Test

Tester Display
Blower Motor

OK

END (BLOWER RESISTOR WAS DEFECTIVE)

NG

REPLACE BLOWER ASSEMBLY (BLOWER MOTOR WITH FAN SUB-ASSEMBLY)