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Operational CheckNBHA0019The purpose of the operational check is to confirm that the system
operates properly.
CONDITIONS:NBHA0019S01IEngine running and at normal operating temperature.
RHA864H
RHA335HA
PROCEDURE:NBHA0019S021. Check Memory FunctionNBHA0019S02011. Set the temperature 85ÉF or 32ÉC.
2. Press OFF switch.
3. Turn the ignition off.
4. Turn the ignition on.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous tempera-
ture.
7. Press OFF switch.
If NG, go to trouble diagnosis procedure for memory function (HA-
126).
If OK, continue with next check.
RHA457GA
RHA329HA
2. Check BlowerNBHA0019S02021. Press fan switch (up side) one time.
Blower should operate on low speed.
The fan symbol should have one blade lit
.
2. Press fan switch (up side) one more time, and continue check-
ing blower speed and fan symbol until all speeds are checked.
3. Leave blower on MAX speed
.
If NG, go to trouble diagnosis procedure for blower motor (HA-95).
If OK, continue with next check.
TROUBLE DIAGNOSES
Operational Check
HA-66
Page 1866 of 2395
RHA865H
RHA330HA
3. Check Discharge AirNBHA0019S02031. Press MODE switch four times and D/F button.
2. Each position indicator should change shape.
RHA654F
3. Confirm that discharge air comes out according to the air dis-
tribution table at left.
Refer to ªDischarge Air Flowº (HA-25).
NOTE:
Confirm that the compressor clutch is engaged (visual inspection)
and intake door position is at FRESH when the DEF
is
selected.
Intake door position is checked in the next step.
If NG, go to trouble diagnosis procedure for mode door motor
(HA-75).
If OK, continue with next check.
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TROUBLE DIAGNOSES
Operational Check (Cont'd)
HA-67
Page 1867 of 2395
RHA459GA
RHA331HA
4. Check RecirculationNBHA0019S02041. Press RECswitch.
Recirculation indicator should illuminate.
2. Listen for intake door position change (you should hear blower
sound change slightly).
If NG, go to trouble diagnosis procedure for intake door (HA-87).
If OK, continue with next check.
RHA460GA
RHA332HA
5. Check Temperature DecreaseNBHA0019S0205Without Navigation System
1) Press the temperature decrease button until 18ÉC (65ÉF) is
displayed.
2) Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for insufficient cooling
(HA-112).
If OK, continue with next check.
With Navigation System
ITurn the temperature dial counterclockwise until 18ÉC (65ÉF)
is displayed.
ICheck for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for insufficient cooling
(HA-112).
If OK, continue with next check.
TROUBLE DIAGNOSES
Operational Check (Cont'd)
HA-68
Page 1868 of 2395

RHA461GA
SHA278FA
6. Check Temperature IncreaseNBHA0019S0206Without Navigation System
IPress the temperature increase button until 32ÉC (85ÉF) is
displayed.
ICheck for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for insufficient heating
(HA-121).
If OK, continue with next check.
With Navigation System
ITurn the temperature dial clockwise until 32ÉC (85ÉF) is dis-
played.
ICheck for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for insufficient heating
(HA-121).
If OK, continue with next check.
RHA462GA
RHA333HA
7. Check ECON (Economy) ModeNBHA0019S02071. Set the temperature 75ÉF or 25ÉC.
2. Press ECON switch.
3. Display should indicate ECON (no AUTO).
Confirm that the compressor clutch is not engaged (visual
inspection).
(Discharge air and blower speed will depend on ambient, in-
vehicle and set temperatures.)
If NG, go to trouble diagnosis procedure for ECON (Economy)
mode (HA-128).
If OK, continue with next check.
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TROUBLE DIAGNOSES
Operational Check (Cont'd)
HA-69
Page 1869 of 2395

RHA463GA
RHA334HA
8. Check AUTO ModeNBHA0019S02081. Press AUTO switch.
2. Display should indicate AUTO (no ECON).
Confirm that the compressor clutch engages (audio or visual
inspection).
(Discharge air and blower speed will depend on ambient, in-
vehicle and set temperatures.)
If NG, go to trouble diagnosis procedure for A/C system (HA-71),
then if necessary, trouble diagnosis procedure for magnet clutch
(HA-104).
SHA286HA
9. Check Ambient Display (With Navigation System)NBHA0019S02091. Press AUTO switch.
2. Press AMB switch.
3. Display should show the outside (ambient) temperature for
approximately 5 seconds.
If NG, go to trouble diagnosis procedure for multiplex communica-
tion circuit (HA-142).
If all operational check are OK (symptom can not be duplicated),
go to ªIncident Simulation Testsº (GI section) and perform tests as
outlined to simulate driving conditions environment. If symptom
appears, refer to ªSymptom Tableº (HA-65) and perform applicable
trouble diagnosis procedures.
TROUBLE DIAGNOSES
Operational Check (Cont'd)
HA-70
Page 1870 of 2395
A/C System
TROUBLE DIAGNOSIS PROCEDURE FOR A/C SYSTEM=NBHA0089SYMPTOM:
IA/C system does not come on.
INSPECTION FLOW
RHA866H
*1: HA-72 *2: HA-66 *3: HA-142
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TROUBLE DIAGNOSES
A/C System
HA-71
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RHA464GA
RHA858H
MAIN POWER SUPPLY AND GROUND CIRCUIT CHECKNBHA0037Component DescriptionNBHA0037S01Automatic Amplifier (Auto Amp.)NBHA0037S0101The auto amplifier has a built-in microcomputer which processes
information sent from various sensors needed for air conditioner
operation. The air mix door motor, mode door motor, intake door
motor, blower motor and compressor are then controlled.
The auto amplifier is unitized with control mechanisms. Signals
from various switches and Potentio Temperature Control (PTC) are
directly entered into auto amplifier.
Self-diagnostic functions are also built into auto amplifier to provide
quick check of malfunctions in the auto air conditioner system.
RHA464GA
RHA867H
Potentio Temperature Control (PTC)NBHA0037S0102The PTC is built into the A/C auto amp. or Display & NAVI control
unit. It can be set at an interval of 0.5ÉC (1.0ÉF) in the 18ÉC (65ÉF)
to 32ÉC (85ÉF) temperature range by pushing the temperature but-
ton. The set temperature is digitally displayed.
TROUBLE DIAGNOSES
A/C System (Cont'd)
HA-72
Page 1872 of 2395
RHA817H
DIAGNOSTIC PROCEDURENBHA0107SYMPTOM:
IA/C system does not come on.
RHA818H
Auto Amp. CheckNBHA0107S01Check power supply circuit for auto amp. with ignition switch ON.
Measure voltage across terminal Nos. 26, 27, 33 (24, 25, 33) and
body ground.
Voltmeter terminal
Voltage
(+) (þ)
26 (24)
Body ground Approx. 12V 27 (25)
33 (33)
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TROUBLE DIAGNOSES
A/C System (Cont'd)
HA-73