Page 25 of 2543
±MEMO±
± AIR CONDITIONING SYSTEMTROUBLESHOOTINGAC±25
Page 26 of 2543

MATRIX CHART OF PROBLEM SYMPTOMS
If a normal code is displayed during the diagnostic sensor check but the trouble still occurs, perform trouble-
shooting for each problem symptom, checking the circuits for each symptom in the order given in the table
below (Proceed to the page given for each circuit).
AC±28
AC±30
AC±32
AC±34
AC±36
AC±38
AC±40
AC±42
AC±44
AC±46
AC±48
AC±50See page
Suspect Area
Symptom
Whole functions of the A/C system does not operate.
No blower operation
No blower control
Insufficient air flow
No cool air comes out
No warm air comes out
Output air is warmer or colder than the set
temperature or response is slow
No temperature control
(only Max. cool or Max. warm)
No air inlet control
No air outlet control
Engine idle up does not occur, or is continuous
Blinking of A/C indicator
Trouble code not recorded.
Set mode is cleared when IG switch is turned off.
Temperature Control
Air Flow Control
Room temp. sensor circuitAmbient temp. sensor
circuitEvaporator temp. sensorcircuitSolar sensor circuitEngine coolant temp. sensor
circuitPressure switch circuitAir mix damper positionsensor circuitAir mix damper controlservo motor circuitAir inlet damper controlservo motor circuitAir outlet damper controlservo motor circuitCompressor lock sensorcircuitAir outlet damper positionsensor circuit
AC±26± AIR CONDITIONING SYSTEMTROUBLESHOOTING
Page 27 of 2543
HINT:
wIf the instruction ºProceed to next circuit inspection shown on matrix chart is given in the flow chart
for each circuit, proceed to the circuit with the next highest number in the table to continue the check.
wIf the trouble still reappears even though there are no abnormalities in any of the other circuits, then
check or replace the A/C amplifier.
AC±52
AC±54
AC±56
AC±58
AC±60
AC±62
AC±66
AC±69
IN±35
AC±71
AC±76
AC±77
AC±107
AC±92
AC±91
AC±95
AC±96
AC±98
AC±97
IG power source circuitBackup power source
circuitACC power source circuitHeater relay circuitCompressor circuitBlower motor circuitA/C amplifierTemperature set dial circuitA/C control assembly circuitRefrigeration system inspection
with manifold gauge setElectric cooling fanWater valveDrive belt tensionRefrigerant volumeCondenserExpansion valveEvaporatorHeater radiatorReceiver
± AIR CONDITIONING SYSTEMTROUBLESHOOTINGAC±27
Page 28 of 2543
CIRCUIT INSPECTION
Blinking Light FACE Room Temperature Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the temperature inside the cabin and sends the appropriate signals to the A/C am-
plifier.
Diagnostic Sensor Check Detecting Condition
Open or short in room temperature sensor circuit.
Trouble Area
Room temperature sensor
Harness or connector between room temperature
sensor and A/C amplifier
A/C amplifier
AC±28± AIR CONDITIONING SYSTEMTROUBLESHOOTING
Page 29 of 2543

INSPECTION PROCEDURE
Proceed to next circuit inspection shown on matrix
chart (See page AC±26). However, if the light is still
blinking, check and replace A/C amplifier.
(See page IN±30).(See Page IN±30).
Remove A/C amplifier with connectors still con-
nected.
Check voltage between terminals TR and SG of A/C amplifier connector.
Check room temperature sensor.
Check harness and connector between A/C amplifier and room
temperature sensor (See page
IN±30).
Replace room temperature sensor.
Repair or replace harness or connector.
Check and replace A/C amplifier.
1. Turn ignition switch ON.
2. Measure voltage between terminal TR of SG
of A/C amplifier connector at each temperature.
1. Remove instrument panel.
2. Disconnect room temperature sensor connector.
Check resistance between terminals 1 and 2 of room
temperature sensor connector.
Resistance:
at 25°C (77°F): 1.6 ~ 1.8 k
HINT: As the temperature increases, the voltage decreases
gradually.
Voltage:
at 25°C (77°F): 1.8 ~ 2.2 V
at 40°C (104°F): 1.2 ~ 1.6 V
± AIR CONDITIONING SYSTEMTROUBLESHOOTINGAC±29
Page 30 of 2543
CIRCUIT DESCRIPTION
This sensor detects the ambient temperature and sends the appropriate signals to the A/C amplifier.
Diagnostic Sensor Check Detecting Condition
Open or short in ambient temperature sensor circuit.
Trouble Area
Ambient temperature sensor
Harness or connector between ambient tempera±
ture sensor and A/C amplifier
A/C amplifier
Blinking Light B L Ambient Temperature Sensor Circuit
AC±30± AIR CONDITIONING SYSTEMTROUBLESHOOTING
Page 31 of 2543

(See page AC±26)
(See page IN±30).
Check voltage between terminals TAM and SG of A/C amplifier connector.
Check ambient temperature sensor.
Check harness and connector between A/C amplifier and ambient
temperature sensor (See page
IN±30).
Proceed to next circuit inspection shown on matrix
chart (See page AC±26). However, if the light is still
blinking, check and replace A/C amplifier.
Check and replace A/C amplifier.
Repair or replace harness or connector.
Replace ambient temperature sensor.
Remove A/C amplifier with connectors still con-
nected.
1. Turn ignition switch ON.
2. Measure voltage between terminal TAM of SG
of A/C amplifier connector at each temperature.
HINT: As the temperature increases, the voltage decreases
gradually.
Voltage:
at 25°C (77°F): 1.35 ~ 1.75 V
at 40°C (104°F): 0.85 ~ 1.25 V
1. Remove the clip and the sensor from the right
side inside the bumper reinforcement.
2. Disconnect ambient temperature sensor connec±
tor.
Check resistance between terminals 1 and 2 of ambi-
ent temperature sensor connector at each tempera-
ture.
Resistance:
at 25°C (77°F): 1.6 ~ 1.8 k
at 50°C (122°F): 0.5 ~ 0.7 k
HINT: As the temperature increases, the resistance
decreases gradually.
NOTICE:
When installing the ambient temperature sensor,
be sure to connect the sensor connector before
connecting the battery.
INSPECTION PROCEDURE
± AIR CONDITIONING SYSTEMTROUBLESHOOTINGAC±31
Page 32 of 2543
Blinking Light FOOT Evaporator Temperature Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the temperature inside the cooling unit and sends the appropriate signals to the
A/C amplifier.
Diagnostic Sensor Check Detecting ConditionTrouble Area
Open or short in evaporator temperature sensor
circuit.Evaporator temperature sensor
Harness or connector between evaporator
temperature sensor and A/C amplifier
A/C amplifier
AC±32± AIR CONDITIONING SYSTEMTROUBLESHOOTING