Page 889 of 1226
AUXILIARY MECHANISM: Temperature setting trimmer
The trimmer compensates for differences in range of 3ÉC between
temperature setting (displayed digitally) and temperature felt by
driver.
Operating procedures for this trimmer are as follows:
+Begin Self-diagnosis STEP 4 mode.
+Press
(fan) switch to set system in auxiliary mode.
+Turn temperature dial clockwise or counterclockwise as
desired. Temperature will change at a rate of 1ÉC each time a
switch is pressed.
When battery cable is disconnected, trimmer operation is can-
celed. Temperature set becomes that of initial condition, i.e.
0ÉC.
RHA581G
TROUBLE DIAGNOSESAUTO
Self-diagnosis (Cont'd)
HA-68
Page 890 of 1226

How to Perform Trouble Diagnoses for Quick
and Accurate Repair
WORK FLOW
*1: Operational Check (HA-70)
SYMPTOM TABLE
Symptom Reference page
+A/C system does not come on.+Go to Trouble Diagnosis Procedure for A/C system. HA-73
+Air outlet does not change.
+Go to Trouble Diagnosis Procedure for Mode Door Motor.
(LAN).HA-75
+Mode door motor does not operate nor-
mally.
+Discharge air temperature does not
change.
+Go to Trouble Diagnosis Procedure for Air Mix Door Motor
(LAN).HA-79
+Air mix door motor does not operate nor-
mally.
+Intake door does not change.
+Go to Trouble Diagnosis Procedure for Intake Door Motor. HA-82
+Intake door motor does not operate nor-
mally.
+Blower motor operation is malfunctioning.
+Go to Trouble Diagnosis Procedure for Blower Motor. HA-86
+Blower motor operation is malfunctioning
under out of starting fan speed control.
+Magnet clutch does not engage.+Go to Trouble Diagnosis Procedure for Magnet Clutch. HA-92
+Insufficient cooling.+Go to Trouble Diagnosis Procedure for Insufficient Cooling. HA-98
+Insufficient heating.+Go to Trouble Diagnosis Procedure for Insufficient Heating. HA-99
+Noise.+Go to Trouble Diagnosis Procedure for Noise. HA-100
+Self-diagnosis cannot be performed.+Go to Trouble Diagnosis Procedure for Self-diagnosis. HA-101
+Memory function does not operate.+Go to Trouble Diagnosis Procedure for Memory Function. HA-102
SHA900E
TROUBLE DIAGNOSESAUTO
HA-69
Page 891 of 1226
Operational Check
The purpose of the operational check is to con®rm that the system
operates properly.
CONDITIONS
+Engine running and at normal operating temperature.
PROCEDURE
1. Check memory function
a. Set the temperature 25ÉC.
b. Press OFF switch.
c. Turn the ignition off.
d. Turn the ignition on.
e. Press the AUTO switch.
f. Con®rm that the set temperature remains at previous tempera-
ture.
g. Press OFF switch.
2. Check blower
a. Press fan switch one time.
Blower should operate on low speed.
The fan symbol should have one blade lit
.
b. Press fan switch one more time, and continue checking blower
speed and fan symbol until all speeds are checked.
c. Leave blower on MAX speed
.
3. Check discharge air
a. Press mode switch four times and DEF button.
RHA517G
RHA518G
RHA519G
RHA520G
TROUBLE DIAGNOSESAUTO
HA-70
Page 892 of 1226
b. Con®rm that discharge air comes out according to the air dis-
tribution table at left.
Refer to ``Discharge Air Flow'' (HA-13).
NOTE:
Con®rm that the compressor clutch is engaged (visualinspec-
tion) and intake door position is at FRESH when the DEF
is selected.
Intake door position is checked in the next step.
4. Check recirculation
a. Press RECswitch.
Recirculation indicator should illuminate.
b. Listen for intake door position change (you should hear blower
sound change slightly).
5. Check temperature dial
a. Turn temperature dial counterclockwise until 18ÉC is displayed.
b. Check for cold air at discharge air outlets.
c. Turn temperature dial clockwise until 32ÉC is displayed.
d. Check for hot air at discharge air outlets.
RHA654FD
RHA521G
RHA522G
TROUBLE DIAGNOSESAUTO
Operational Check (Cont'd)
HA-71
Page 893 of 1226
6. Check AUTO mode
a. Press AUTO switch.
b. Display should indicate AUTO.
Con®rm that the compressor clutch engages (audio or visual
inspection).
(Discharge air and blower speed will depend on ambient,
in-vehicle, and set temperatures.)
7. Check FRESH switch
a. Press FRE switch.
FRESH indicator should illuminate.
b. Listen for intake door position change. (You should hear a slight
change in blower sound.)
8. Check A/C switch
a. Press A/C switch.
A/C indicator should illuminate.
b. Con®rm that the compressor clutch is engaged.
RHA523G
RHA524G
RHA525G
TROUBLE DIAGNOSESAUTO
Operational Check (Cont'd)
HA-72
Page 894 of 1226

A/C System
TROUBLE DIAGNOSIS PROCEDURE FOR A/C SYSTEM
SYMPTOM:
+A/C system does not come on.
Inspection ¯ow
*1: HA-74 *2: HA-70
COMPONENT DESCRIPTION
Automatic ampli®er (Auto amp.)
The auto ampli®er 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 ampli®er is unitized with control mechanisms. Signals
from various switches and Potentio Temperature Control (PTC) are
directly entered into auto ampli®er.
Self-diagnostic functions are also built into auto ampli®er to provide
quick check of malfunctions in the auto air conditioner system.
Potentio temperature control (PTC)
The PTC is built into the A/C auto amp. It can be set at an interval
of 1ÉC in the 18ÉC to 32ÉC temperature range by turning the tem-
perature dial. The set temperature is digitally displayed.
SHA019F
RHA629G
RHA746G
TROUBLE DIAGNOSESAUTO
HA-73
Page 895 of 1226
DIAGNOSTIC PROCEDURE
Auto amp. check
Check power supply circuit for auto amp. with ignition switch ON.
Measure voltage across terminal Nos.j
1,j2,j20and body ground.
Voltmeter terminal
Voltage
%@
j
1
Body ground Approx. 12V j2
j20
RHA632G
RHA633G
TROUBLE DIAGNOSESAUTO
A/C System (Cont'd)
HA-74
Page 896 of 1226
Mode Door Motor
TROUBLE DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR (LAN)
SYMPTOM:
+Air outlet does not change.
+Mode door motor does not operate normally.
Inspection ¯ow
*1: HA-13
*2: HA-70
*3: HA-64
*4: HA-65
*5: HA-66*6: HA-67
*7: HA-103
*8: HA-105
*9: HA-107
*10: HA-110*11: HA-79
*12: HA-65
*13: HA-77
*14: HA-70
*15: HA-69
SHA020F
TROUBLE DIAGNOSESAUTO
HA-75