Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-39
Diagnostic Information and Procedures
A/C System Symptom DiagnosisS7RS0B7224001
4. Rear defogger relay 15. Evaporator temperature sensor 26. Radiator cooling fan relay No.1 37. Rear defogger switch
5. Rear defogger 16. Sunload sensor 27. Radiator cooling fan relay No.2 38. To BCM
6. Blower motor relay 17. Junction block assembly 28. Radiator cooling fan relay No.3 39. To ECM
7. Blower motor 18. ECM 29. Information display 40. To main relay
8. Blower motor controller 19. ECT sensor 30. Lighting switch 41. To main fuse
9. DLC 20. Radiator cooling fan motor 31. A/C switch 42. Back-light
10. Air intake actuator 21. Compressor relay 32. MODE (air flow) selector 43. Defroster indicator 11. Air flow control actuator 22. Compressor 33. Air intake selector 44. Rear defogger indicator
Condition Possible cause Correction / Reference Item
No cool air comes out (A/
C system does not
operate) No refrigerant
Perform recovery, evacuation and charge
referring to “Operation Procedure for
Refrigerant Charge”.
Fuse blown Check related fuses, and then check for short
circuit to ground.
A/C switch faulty Check A/C switch referring to “Inspection of
HVAC Control Module and Its Circuit”.
Evaporator temperature sensor faulty Check evaporator temperature sensor
referring to “Evaporator Thermistor
(Evaporator Temperature Sensor) Inspection”.
A/C refrigerant pressure sensor faulty Check A/C refrigerant pressure sensor
referring to “A/C Refrigerant Pressure Sensor
and Its Circuit Inspection”.
Wiring or grounding faulty Repair as necessary.
ECT sensor faulty Check ECT sensor referring to “ECT Sensor
Inspection in Section 1C”.
ECM faulty Check ECM referring to “A/C System
Inspection at ECM”.
HVAC control module faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
Magnet clutch faulty Check magnet clutch. Referring to “Magnet
Clutch Inspection”.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Compressor faulty Check compressor.
Compressor relay faulty Check compressor relay referring to
“Compressor Relay Inspection”.
Temperature selector, blower speed
selector, and/or air flow selector faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
BCM faulty Check BCM referring to “Inspection of BCM
and its Circuits in Section 10B”.
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-41
Cool air does not come
out or insufficient cooling
(A/C system normal
operation)Insufficient or excessive charge of
refrigerant
Check the amount of refrigerant and system
for leaks.
Condenser clogged Check condenser referring to “Condenser
Assembly On-Vehicle Inspection”.
A/C evaporator clogged or frosted Check A/C evaporator and evaporator
temperature sensor referring to “Evaporator
Inspection” and “Evaporator Thermistor
(Evaporator Temperature Sensor) Inspection”.
Evaporator temperature sensor faulty Check evaporator temperature sensor
referring to “Evaporator Thermistor
(Evaporator Temperature Sensor) Inspection”.
Expansion valve faulty Check expansion valve referring to “Expansion
Valve Inspection”.
Desiccant clogged Replace receiver/dryer.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Magnet clutch faulty Check magnet clutch. Referring to “Magnet
Clutch Inspection”.
Compressor faulty Check compressor.
Air in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Air leaking from HVAC unit or air duct Repair as necessary.
Heater and ventilation system faulty Check HVAC unit.
Temperature selector faulty Check temperature selector referring to
“Inspection of HVAC Control Module and Its
Circuit”.
HVAC control module faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
Temperature control actuator faulty Check temperature control actuator referring to
“Temperature Control Actuator Inspection”.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Excessive compressor oil in A/C system Drain excessive compressor oil from A/C
system circuit and compressor.
Cool air does not come
out only intermittently Wiring connection faulty
Repair as necessary.
Expansion valve faulty Check expansion valve referring to “Expansion
Valve Inspection”.
Excessive moisture in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Magnet clutch faulty Check magnet clutch. Referring to “Magnet
Clutch Inspection”.
Excessive amount of refrigerant Check the amount of refrigerant.
Cool air comes out only at
high speed Condenser clogged
Check condenser referring to “Condenser
Assembly On-Vehicle Inspection”.
Insufficient charge of refrigerant Check the amount of refrigerant and system
for leaks.
Air in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Compressor faulty Check compressor.
Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-47
Scan Tool Data Definitions
TEMP CONT SWITCH (TEMPERATURE SELECTOR): Position of temperature control
selector of HVAC control module
CABIN TEMPERATURE: In-car temperature detected
by inside air temperature sensor installed in HVAC
control module
OUTSIDE AIR TEMP (OUTSIDE AIR TEMPERATURE): Outside air temperature
detected by outside air temperature sensor installed
in front bumper member
EVAPORATOR TEMP (EVAPORATOR TEMPERATURE): Temperature of air passed
through evaporator
COOLANT TEMP (ENGINE COOLANT TEMPERATURE): Engine coolant temperature
detected by engine coolant temperature sensor
SUN LOAD: Amount of sunlight detected by sunload
sensor installed on the driver side on the dashboard
MODE CONT SWITCH (MODE (AIR FLOW) SELECTOR): Position of air flow selector of HVAC
control module
FAN CONT SWITCH (BLOWER SPEED SELECTOR): Position of blower speed selector of HVAC control
module
FAN DESIRED VOLT: Voltage for blower motor AIR MIX POS SEN (TEMPERATURE CONTROL
ACTUATOR POSITI ON SENSOR): Input signal
from position sensor in temperature control actuator
MODE POS SENSOR (AIR FLOW CONTROL ACTUATOR POSITI ON SENSOR): Input signal
from position sensor in air flow control actuator
A/C CONT SIG (A/C SWITCH SIGNAL, ON or OFF): State of A/C switch
BLOWER LOAD SIG (BLO WER FAN LOAD SIGNAL,
ON or OFF): ON: Position of blower speed selector
is 1st position or more / OFF: Position of blower
speed selector is OFF position.
AIR INTAKE MODE (AUTO, FRE or REC): State of air
intake mode
REFRIGERANT PRESSURE (A/C REFRIGERANT ABSOLUTE PRESSURE): This parameter
indicates A/C refrigerant absolute pressure
calculated by ECM
A/C COMP CLUTCH (A/C COMPRESSOR MAGNET CLUTCH, ON or OFF): This parameter indicates
the state of the A/C switch
DFR INDICATOR (DEFROSTER INDICATOR LAMP, ON or OFF): State of defroster indicator lamp
VEHICLE SPEED: It is computed based on pulse
signals from vehicle speed sensor
Air Conditioning System CheckS7RS0B7224008
Step Action YesNo
1 Customer complaint analysis
1) Perform )”Customer complaint analysis”.
Was customer complaint analysis performed? Go to Step 2.
Perform customer
complaint analysis.
2 Visual inspection
1) Perform )“Visual inspection”.
Is there any faulty condition? Repair or replace
malfunction part.
Go to Step 3.
3 DTC check
1) Perform )“DTC check”.
Is there any DTC code? Go to Step 4.
Go to Step 5.
4 Troubleshooting malfunction
1) Perform ) “Troubleshooting malfunction”.
Is there any faulty condition? Repair or replace
malfunction part, and go
to Step 7.
Go to Step 5.
5 Perform A/C system symptom diagnosis
1) Inspect and repair referri ng to “A/C System Symptom
Diagnosis”.
Is there any faulty condition? Repair or replace
malfunction part, and go
to Step 7.
Go to Step 6.
6 Check for intermittent problem
1) Check for intermittent troubles referring to “Intermittent
and Poor Connection Inspection in Section 00”.
Is there any faulty condition? Repair or replace
malfunction part, and go
to Step 7.
Go to Step 7.
7 Final confirmation test
1) Perform ) “Final confirmation test”.
Is there any malfunction code? Go to Step 4.
End.