Page 32 of 656

AIR CONDITIONING (OPTIONAL) 1B-7
Cool air does not
come out or insuffi-
cient cooling (A/C sys-
tem normal operative)Insufficient or excessive charge of refrigerant Check charge of refrigerant.
Refrigerant leak in system Check system for leaks.
Condenser clogged Check condenser.
A/C evaporator clogged or frosted Check A/C evaporator.
A/C evaporator temperature sensor (A/C evap-
orator thermistor) faultyCheck A/C evaporator tempera-
ture sensor (A/C evaporator ther-
mistor).
A/C controller faulty Check A/C controller.
Expansion valve faulty Check expansion valve.
Drive belt slipping Check or replace drive belt.
Magnetic clutch faulty Check magnetic clutch.
Cool air does not
come out or insuffi-
cient cooling (A/C sys-
tem normal operative)Compressor faulty Check compressor.
Air in A/C system Replace condenser dryer, and then
perform evacuation and charging.
Air leaking from cooling unit or air duct Repair as necessary.
Heater and ventilation system faulty Check air inlet box assembly.
Check heater control lever assem-
bly.
Check heater assembly.
Blower motor faulty Check blower motor.
Excessive compressor oil existing in A/C sys-
temPull out compressor oil in A/C sys-
tem circuit, and replace compres-
sor.
Cool air does not
comes out only inter-
mittentlyWiring connection faulty Repair as necessary.
Expansion valve faulty Check expansion valve.
Excessive moisture in A/C system Replace condenser dryer, and then
perform evacuation and charging.
A/C controller faulty Check A/C controller.
Magnetic clutch faulty Check magnetic clutch.
Excessive charge of refrigerant Check charge of refrigerant.
Cool air comes out
only at high speedsCondenser clogged Check condenser.
Insufficient charge of refrigerant Check charge of refrigerant.
Air in A/C system Replace condenser dryer, and then
perform evacuation and charging.
Drive belt slipping Adjust or replace drive belt.
Compressor faulty Check compressor.
Cool air does not
comes out only at high
speedsExcessive charge of refrigerant Check charge refrigerant.
A/C evaporator frosted Check A/C evaporator.
Check A/C thermistor.
Insufficient velocity of
cooled airA/C evaporator clogged or frosted Check A/C evaporator.
Air leaking from cooling unit or air duct Repair as necessary.
Blower motor faulty Check blower motor.
Wiring or grounding faulty Repair as necessary. Condition Possible Cause Correction
Page 39 of 656

1B-14 AIR CONDITIONING (OPTIONAL)
Wiring Circuit
ACG
LT GRN
PNK
PNK
BLKORN
BLK
YEL/GRNRED/BLKBLK/WHT
BLU/WHTPNK/BLK
PNK/GRN
RED/BLK
WHT/RED
YEL/GRN
YEL/BLU
A/C
RED/BLU
RED/BLU
RED/BLKBLK
BLU/ORN
BLU/WHT
BLU/WHT
PNK
PNK/BLU
BLK
PNK/WHT
YEL/BLK
GRY/WHT
GRN/BLK
BLK/WHT
RED/BLK
YEL/GRN
BLK
BLK
BLK
YEL/BLK
YEL/GRN
YEL/GRNBLU/GRN
BLU/YELBLUBLU/BLK
BLU/BLK
17
21
22 18
16
15
19
2026 25 24 23
14
12
29
3
4
7
33 30
31
32
28
27
1213
10
11
35 349
856
A
1. Front blower motor main relay 10. Compressor relay 19. Battery 28. Solenoid valve relay
2. Front blower motor 11. Compressor 20. Generator 29. Rear blower motor relay
3. Front blower motor resistor 12. Condenser cooling fan motor
relay21. Ignition main fuse 60 A 30. Rear blower motor resistor
4. Front blower motor switch 13. Condenser cooling fan motor 22. Heater/A/C main fuse 60 A 31. Rear blower motor
5. A/C controller 14. Fuse box 23.“IG METER” fuse 20 A 32. Rear blower motor switch
6. ECM (PCM) 15.“A/C” fuse 25 A 24.“REAR DEFG” fuse 25 A 33. Rear A/C main switch
7. Heater mode control switch 16. Ignition switch 25.“REAR BLOW” fuse 20A 34. Rear A/C evaporator temperature con-
troller
8. Dual (refrigerant) pressure switch 17. Main fuse box 26.“FRONT BLOW” fuse 30A 35. Rear A/C evaporator temperature sensor
9. A/C evaporator thermistor
(A/C evaporator temperature sensor)18. Battery main fuse 100 A 27. Solenoid valve [A] : Rear A/C wiring circuit (if equipped)
Page 284 of 656

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-123
Table B-5 A/C Signal Circuits Inspection (If Equipped)
WIRING DIAGRAM
INSPECTION
1. A/C control module (amplifier)
2. ECM (PCM)
Step Action Yes No
1 Check A/C Signal Circuit.
1) Check voltage at terminal E61-17 with ignition
switch ON.
A/C signal circuit specification :
A/C switch and/or heater blower switch OFF (A/
C is not operating) : 10 – 14 V
Both A/C switch and heater blower switch ON :
0 – 1.5 V
Are check result as specified?Go to Step 2.“YEL/BLK” circuit open or
short, Evaporative tem-
perature is below 1°C
(34°F) or faulty A/C sys-
tem.
2 Check A/C Cut Signal Circuit.
1) Check voltage at terminal E61-8.
A/C cut signal specification :
While engine running and A/C switch and/or
heater blower switch OFF
(A/C is not operating) : 0 – 1.5 V
While engine running at idle speed and both A/
C switch and heater blower switch ON
(A/C is operating) : 10 – 14 V
Are check result as specified?A/C control signal cir-
cuits are in good con-
dition.“GRY/WHT” circuit open
or short, Poor perfor-
mance of ECT sensor, TP
sensor, Engine start sig-
nal inputted or A/C ampli-
fier malfunction.
If none of the above
exists, substitute a
known-good ECM (PCM)
and recheck.