
FULL-AUTOMATIC AIR CONDITIONER –
Troubleshooting
55-44
Inspection procedure 3
A/C graphic display on control panel is blank.
Probable cause
The cause is probably a malfunction of the A/C-ECU power supply system
(earth).
D
Malfunction of connector or harness
D
Malfunction of A/C-ECU
Does the A/C operate?
NO
Inspection procedure 15 (Refer to P.55-52.)
YES
Replace the A/C-ECU.
Inspection procedure 4
Temperature cannot be set.
Probable cause
The cause is probably a malfunction of the temperature setting signal input
system or output system.
D
Malfunction of connector or harness
D
Malfunction of A/C-ECU
Inspection procedure 15 (Refer to P.55-52.)
Inspection procedure 5
A/C outlet air temperature does not increase.
Probable cause
If the outlet air temperature does not increase when the temperature setting is
increased, the cause is probably a sensor malfunction or a problem with
operation of the air mix damper. The MUT-
II
can be used to check the
diagnosis codes in order to check the cause of the problem for each separate
system.
D
Malfunction of air mix damper potentiometer
D
Malfunction of air mix damper motor
D
Malfunction of air mix damper
D
Malfunction of connector or harness
D
Malfunction of thermostat
D
Malfunction of A/C-ECU
MUT-
II
Self-Diag code
Is any of the codes 11, 12, 31 and 41 output?
YES
INSPECTION CHART FOR DIAGNOSIS CODES (Refer to
P.55-34.)
NO
Thermostat check
NG
Replace
OK
Replace the A/C-ECU.
Inspection procedure 6
A/C outlet air temperature does not decrease.
Probable cause
If the outlet air temperature does not decrease when the temperature setting is
decreased, the cause is probably a problem in A/C system operation due to a
sensor error, or a problem with operation of the air mix damper. The MUT-
II
can be used to check the diagnosis codes in order to check the cause of the
problem for each separate system.
D
Malfunction of outside air temperature sensor
D
Malfunction of air mix damper potentiometer
D
Malfunction of air mix damper motor
D
Malfunction of air thermo sensor
D
Malfunction of connector or harness
D
Malfunction of air mix damper
D
Malfunction of A/C-ECU
Does the A/C operate?
NO
Inspection procedure 2 (Refer to P.55-43.)
YES
MUT-
II
Self-Diag code
Is any of the codes 11, 12, 13, 14, 21, 22, 31 and 41 output?
YES
INSPECTION CHART FOR DIAGNOSIS CODES (Refer to
P.55-34.)
NO
Replace the A/C-ECU.