Page 217 of 3573

AIR CONDITIONING 1BÐ91
6. Heating Start Timing Control
When the automatic heater/air conditioner is
started, heating is turned on under following
conditions.
·The detected temperature of thermo unit is
136¡F or less.
·The temperature setting signal and the total
signal by each sensor meet the condition of
heating.
When the detected temperature by the coolant
temperature sensor is 136¡F or less the blower
fan motor is set to work at low speed and the
"DEF" mode is selected.
When the detected temperature by the coolant
temperature sensor is 77¡F or more, the blow
mode changes automatic control. And the
blower fan speed is controlled to be lineally up
from "LO" to "MAX HI".7. Cooling Start Timing Control
When the automatic heater/air conditioner is
started, cooling is turned on under following
conditions.
·The in car sensor is 86¡F or more.
·The temperature setting signal and the signals
from each sensor meet the specified condition.
The blower fan speed is set to "LO" for
maximum 7 seconds when cooling start
conditions meet, and then, is controlled to be
lineally up to "MAX HI" by 5.32%/S.
Ignition swich
"ON"
Time
Blower voltage to turn
on the cooling
7 SEC maximum3 SEC
100%
(MAX HI)
33.5%
(LO)5.32%/S
C06RY00001
33.5%
(LO)
2.63%/S
Mode
DEF
Auto
Mode
100%
(MAX HI)
Ignition
switch "ON"
Thermo Unit 58¡C(Gasoline)
52¡C(Diesel) Time
840RY00009
Page 218 of 3573

1BÐ92 AIR CONDITIONING
TROUBLESHOOTING
Troubleshooting, Its Overview and Procedures
The full automatic heater and air conditioner equips with the "Self-Diagnosis Function" to check its major
components.
This function makes access to the sensors, actuators and blower fan motor system easier when checking
them up and, when a failed part is located, this function restores its original performance.
When implementing the troubleshooting, this self-diagnosis function narrows the range to be searched at
the first step, then check relevant parts one by one according to the "Checking Procedures by Failed
Location" As for a location this function is unappreciable, the system accurately determines characteristics
of a given trouble and checks relevant parts according to the "Checking Procedures by Failed Location".
The following illustrates basic troubleshooting flow.
1. Basic Troubleshooting Flow
Occurrence of a trouble
Refer to the check list for
the inspection.Locate the failed location.
Check the failed part.
Correction
Correction
Correction
Troubleshooting by the
self-diagnosis function.Reference the "Check
Procedure by Failed
Location" for the inspection.
Reference the "Check
Procedure by Failed
Location" for the inspection.Correction
Check the cooling / heating
cycles.
End OK OK OK OKNG
NG
NG
NG
NG OK
Check if the automatic
heater / air conditioner
control unit indicator LED
is turned on.Check the power supply and
circuit on the automatic
heater / air conditioner control
unit.
Troubleshooting not relying
on the self-diagnosis
function(troubleshooting
by failure type).
F01RX009
Page 219 of 3573
AIR CONDITIONING 1BÐ93
Check of Auto Amplifier (Automatic air conditioner control unit) Power Supply System
¥ This check is required because a trouble on the auto amplifier (control unit) power supply circuit or
grounding circuit prevents accurate troubleshooting.
Check of auto amplifier
power supply circuit and
grounding circuit.
Chart A
B-18
FL-1 Main
80A
0.5G/R16
107 8
I-32
I-32 C-16
10A0.3R/W
0.5BRBackup
Power supply (12V)
Unit ground
Automatic heater/air conditioner control unit
B-18B-36H-14
C-20
10A A/C
Relay:
Heater and air
conditioner
0.5B
1.25B 2B
Lighting switchLighting switch
H-141H-269
H-2614
H-2720
H-1614 2
14
3 B-36
12
34
H-16
H-26H-27I-32
1
2
1
2
10987654321
222120191815141312111716
12345111213141567891018192021221617
10 11 12 13 14 151234 5
17 18 19 206789
16
9876
20 19 18 17 165
14 154
133
122
111
10
20 12
19 11
18 10
179
168
157
146
13512 34
43 21
12111098765
13 14 15 16 17 18 19 20
12345678
9 10111213141516
D08RY00175
Page 220 of 3573
1BÐ94 AIR CONDITIONING
Chart "A" : Check of Auto Amplifier Power Supply System
NOHarness disconnection or improper grounding.
NOHarness disconnection or improper grounding.
NOHarness disconnection or trouble on lighting
switch.
NOHarness disconnection or improper grounding.
Turn off ignition switch.
Power supply system is free of
trouble.
YES YES
YES YES
Is battery voltage present between chassis
harness connector terminal No.7
and ground?
I-32
Is battery voltage present between
chassis harness connector No.8
and ground?
I-32
Are chassis harness connector No.16
and body ground conducted?
B-18I-32
Turn on ignition switch (engine is started).
Turn on lighting switch.
Is battery voltage present between chassis
harness connector No.10 and
ground?
I-32
Page 221 of 3573

AIR CONDITIONING 1BÐ95
Performance and Movement checklist for Automatic Air Conditioner Related Parts
Start the engine, and when the engine coolant reached 60¡C check performance and movement of the
related parts according the following checklist.
1. Performance Check Using the Manual Switch
Checking ApproachNo.ItemAcceptance criteria
Condition Operation
Blowing
temperature
(check movement
of air mix door)
Airflow volume
(check movement
of the mode door)Set temperature to
25.0¡C.(1) Turn the fan knob
off.
(2) Turn the fan knob
from LOW to HI.(1) The fan shall be stopped, thus
stopping air blow, too.
(2) Airflow volume shall change
from LOW to HI.
Blowing
temperature
(check movement
of the mode door)Set temperature to
25.0¡C.
Set the fan knob to HI.Press the mode switch
to change the blow port
mode sequentially from
the VENT through BI-
LEVEL, FOOT up to
DEF.LED corresponding to each mode
shall be turned on and the blow
port mode shall be switched
smoothly.
The
interior/outside air
switching mode
(check movement
of intake door)Set temperature to
25.0¡C.Turn the LED off using
the interior/outside air
switch (this introduces
the outside air intake
mode). Then, the set
fan knob to HI and
press the
interior/outside switch
to turn on the LED.The LED indication shall be
switched from OFF to ON
accompanying a change in air
blowing sound.
Compressor Set the temperature to
FC. (Outside air
temperature is 0C or
above and interior
temperature at ordinary
temperature.)Press the "OFF" switch.
(1) Press the Auto
switch.
(2) Press the Air
Conditioner switch.(1) As the fan knob is set to the
Auto position, the A/C switch
LED shall come on and the
compressor shall be turned on.
(2) As the A/C LED comes off, the
compressor shall be turned off. Auto switch must be
turned on
(FAN-AUTO
MODE-AUTO)(1) Select FC for the
setup temperature.
(2) Select FH for the
setup temperature.
®Then, select the
MAX Control.(1) Cold air shall be blown out.
(2) Hot air shall be blown out.
1
2
3
4
5
Page 222 of 3573
1BÐ96 AIR CONDITIONING
Checking ApproachNo.ItemAcceptance criteria
Condition Operation
Change the
temperature gradually
starting with 20¡C up to
30¡C.The following phenomena shall be
recognized.
¥ Temperature of blown air: Cold
air is changed to hot air.
¥ Change in the air flow volume.
¥ The blow port mode LED
indication changes in the
following sequence:
Select FH for the
temperature.Cold air shall be blown out.
The following LEDs shall come on.
¥ Blow port mode :
¥ Fan speed: Max Hi Select FC for the
temperature.The LED shall come on.
Cold air shall be blown out.
The following LEDs shall come on:
¥ Blow port mode :
¥ Intake mode
¥ Fan speed : MAX Hi
¥ A/C
1 Full Auto function FAN KNOB ÒAUTOÓ
MODE SW ÒAUTOÓ
2. Check of Full Auto Function
(VENT) (FOOT)(BI-LEVEL)
F01RX003 F01RX002
F01RX004
Page 223 of 3573

AIR CONDITIONING 1BÐ97
TROUBLESHOOTING WITH SELF-DIAGNOSIS FUNCTION
1. Overview of Self-Diagnosis Function
The self-diagnosis is implemented in 3 steps for each target. For detail of check procedure contained in
each step, refer to the relevant section of "Check Procedure by Failed Location" listed in the Self-
Diagnosis Operation Procedure.
For turning on the self-diagnosis function and switching of the check step, refer to the flow chart given
below. You can reset the self-diagnosis function by turning the ignition switch off or turning the DEF
switch on for 3 seconds.
2. Self-Diagnosis Operation Procedure
While holding both the Auto switch and the DEF switch on the
automatic heater/air conditioner panel, turn the IG off and then
on.
Does the A/C LED flash every 0.5 second interval?
Press the A/C switch once.
(The past trouble
diagnosing function will
be turned on.)
Does the A/C LED flashes every 0.5 seconds?
Does each output equipment functions normally according to
operation of the temperature setting lever?
Press the DEF switch for 3
seconds consecutively or turn on
and off the IG.
Failure on the
output equipment
or the harness.
Preparations
(1) Set the IG to the OFF mode.
(2) Apply 60W bulb light to the sun sensor.
(3) Set the temperature setting lever on the automatic heater/air
conditioner panel to the center position (25C).
(4) Set the fan switch on the same panel to the Auto position.
End of the self-diagnosis.(The current trouble diagnosing function will be turned on
approximately in 10 seconds.)
YESNO
YESNO
NO
YES
Refer to *1.
Refer to *2.
Page 224 of 3573

1BÐ98 AIR CONDITIONING
*1. Displaying the Current Trouble Diagnosing Table
Start the engine while holding down both the Auto switch and the DEF switch on the control panel, and
the table will appear in approximately 10 seconds to the indicator lamp (LED) of the air conditioning
switch. Result of the diagnosis along the following 9 items will be shown one by one in 0.5 second
interval irrespective of presence or absence of a trouble for a given item. When the display 9 items is
completed, it is repeated with 3 seconds of interval in between. A failed item is indicated by flashing of
the LED that is repeated 3 times within 0.5 seconds. If a trouble is indicated, you can locate the failed
section by knowing when in the total sequence it has been displayed.
Items for Current Trouble Diagnosis
As shown above, display of result along nine items is repeated with 3-second interval in between.
Note 1: When checking the solar radiation sensor, apply sufficient light using a 60W bulb.
Otherwise, it can be diagnosed as failed.
Note 2: If the temperature setting lever is set on both ends (one set to 18¡C, blue scale = Full cool and
the other to 31¡C, red scale = Full hot), they can be diagnosed as failed.
Note 3: Likewise, the fan switch can be diagnosed as failed if set on both ends.
LED on
LED off Indication for presence
of a troubleIndication for normal state
0.5 0.5 0.5
3 seconds interval
ON
OFF
Display pattern Failed part
Normal pattern
In car sensor
Ambient sensor
Sun sensor (Note 1)
Duct sensor
Temperature control lever (Note 2)
Fan switch (Note 3)
Mix actuator
Mode (blow port) control
Intake (fresh air/interior air switching) control
F01RX010
F01RY00008