Toyota 4Runner: Blower Motor Circuit
DESCRIPTION
The blower with fan motor sub-assembly operates according to signals from the air conditioning amplifier assembly. The blower with fan motor sub-assembly speed signals are transmitted by changes in the duty ratio.
Duty Ratio:
The duty ratio is the ratio of the blower with fan motor sub-assembly on time (T1) to the total of the blower with fan motor sub-assembly on and off time (T2).
The air conditioning amplifier assembly controls the blower with fan motor sub-assembly speed.
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 (BLOWER WITH FAN MOTOR) |
(a) Select the Active Test, use the Techstream to generate a control command,
and then check that the blower with fan motor sub-assembly operates (See page
.gif)
).
Air Conditioner
|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Blower Motor |
Blower with fan motor sub-assembly |
Min.: 0, Max.: 31 |
- |
OK:
Blower with fan motor sub-assembly operates and blower motor speed changes.
| OK | .gif) |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
.gif)
|
2. |
CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR - BATTERY AND BODY GROUND) |
(a) Disconnect the F43 motor connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
F43-3 (+B) - Body ground |
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 |
|---|---|---|
|
F43-1 (GND) - Body ground |
Always |
Below 1 Ω |
|
*a |
Front view of wire harness connector (to Blower with Fan Motor Sub-assembly) |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
3. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BLOWER WITH FAN MOTOR AND BODY GROUND) |
(a) Disconnect the F42 amplifier connector.
(b) Disconnect the F43 motor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
F42-23 (BLW) - F43-2 (SI) |
Always |
Below 1 Ω |
|
F42-23 (BLW) - Body ground |
Always |
10 kΩ or higher |
|
F42-14 (GND) - Body ground |
Always |
Below 1 Ω |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4. |
CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (BLW SIGNAL) |
|
(a) Remove the air conditioning amplifier assembly with its connectors
still connected (See page |
|
(b) Using an oscilloscope, check the waveform.
Measurement Condition|
Item |
Content |
|---|---|
|
Terminal No. (Symbol) |
F42-23 (BLW) - F42-14 (GND) |
|
Tool Setting |
1 V/DIV., 500 μs/DIV. |
|
Condition |
Ignition switch ON Blower switch LO |
OK:
Waveform is as shown in the illustration.
Text in Illustration|
*a |
Component with harness connected (Air Conditioning Amplifier Assembly) |
HINT:
Waveform varies with the blower level.
| NG | |
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
|
|
5. |
REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY |
(a) Replace the blower with fan motor sub-assembly with a new or normally functioning
one (See page ).
(b) Operate the blower with fan motor sub-assembly to check that it functions properly.
OK:
Blower with fan motor sub-assembly operates normally.
| OK | |
END (BLOWER WITH FAN MOTOR SUB-ASSEMBLY IS FAULTY) |
| NG | |
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
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DESCRIPTION
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DESCRIPTION
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Customize Parameters
CUSTOMIZE PARAMETERS
1. CUSTOMIZING FUNCTION WITH TECHSTREAM
HINT:
The following items can be customized.
NOTICE:
When the customer requests a change in a function, first make sure that
the function can be customized.
Record the current se ...
Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
HINT:
Use the table below to help determine the cause of problem symptoms.
If multiple suspected areas are listed, the potential causes of the symptoms
are listed in order of probability in the "Suspected Area" ...
0.0263