Page 3377 of 3833

TROUBLE DIAGNOSIS
ATC-101
C
D
E
F
G
H
I
K
L
MA
B
AT C
2.CHECK AMBIENT SENSOR CIRCUIT BETWEEN AMBIENT SENSOR AND AUTO AMP. (LCU)
Disconnect auto amp. (LCU) harness connector.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3.CHECK AMBIENT SENSOR
Refer to ATC-102, "
Ambient Sensor"
OK or NG
OK >> 1. Replace auto amp. (LCU).
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and perform self-diagnosis STEP-2.Confirm that
code No. 20 is displayed.
NG >> 1. Replace ambient sensor.
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and perform self-diagnosis STEP-2.Confirm that
code No. 20 is displayed.
4.CHECK AMBIENT SENSOR CIRCUIT BETWEEN AMBIENT SENSOR AND AUTO AMP. (LCU)
Disconnect auto amp. (LCU) harness connector.
OK or NG
OK >> 1. Replace auto amp. (LCU).
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and
perform self-diagnosis STEP-2.Confirm that code No.
20 is displayed.
NG >> Repair harness or connector.
Te r m i n a l s
Continuity
ConnectorTerminal (Wire
color)ConnectorTerminal (Wire
color)
E38 2 (B/Y) M53 24 (B/Y) Yes
RJIA1951E
Terminals
Continuity
ConnectorTerminal
(Wire color)ConnectorTe r m i n a l
(Wire color)
E38 1 (L/OR) M52 9 (L/OR) Yes
RJIA1952E
Page 3378 of 3833
ATC-102
TROUBLE DIAGNOSIS
COMPONENT INSPECTION
Ambient Sensor
After disconnecting ambient sensor harness connector, measure
resistance between terminals 2 and 1 at sensor harness side, using
the table below.
If NG, replace ambient sensor.
In-vehicle Sensor CircuitEJS001HC
COMPONENT DESCRIPTION
In-vehicle sensor
The in-vehicle sensor is located on instrument lower panel. It con-
verts variations in temperature of compartment air drawn from the
aspirator into a resistance value. It is then input into the auto ampli-
fier.
Aspirator
The aspirator is located on front side of heater & cooling unit. It pro-
duces vacuum pressure due to air discharged from the heater &
cooling unit, continuously taking compartment air in the aspirator.
Temperature °C (°F) Resistance kΩ
-15 (5) 12.73
-10 (14) 9.92
-5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
RJIA0556E
RJIA0049E
RJIA0557E
Page 3379 of 3833
TROUBLE DIAGNOSIS
ATC-103
C
D
E
F
G
H
I
K
L
MA
B
AT C
DIAGNOSTIC PROCEDURE
SYMPTOM: In-vehicle sensor circuit is open or shorted. (22 or -22 is
indicated on auto amp. as a result of conducting Self-diagnosis
STEP 2.)
1.CHECK IN-VEHICLE SENSOR CIRCUIT BETWEEN IN-VEHICLE SENSOR AND BODY GROUND
Disconnect in-vehicle sensor harness connector.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2.CHECK IN-VEHICLE SENSOR CIRCUIT BETWEEN IN-VEHICLE SENSOR AND AUTO AMP. (LCU)
Disconnect auto amp. (LCU) harness connector.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
RHA482A
RJIA0745E
Terminals
Voltag e (+)
(-)
ConnectorTerminal (Wire
color)
M34 1 (P) Ground Approx. 5V
RJIA0559E
Te r m i n a l s
Continuity
ConnectorTerminal
(Wire color)ConnectorTerminal
(Wire color)
M34 2 (B/Y) M53 24 (B/Y) Yes
RJIA0560E
Page 3380 of 3833

ATC-104
TROUBLE DIAGNOSIS
3. CHECK IN-VEHICLE SENSOR
Refer to ATC-104, "
In-vehicle Sensor"
OK or NG
OK >> 1. Replace auto amp.
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and perform self-diagnosis STEP-2. Confirm
that code No. 20 is displayed.
NG >> 1. Replace in-vehicle sensor.
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and perform self-diagnosis STEP-2. Confirm
that code No. 20 is displayed.
4. CHECK IN-VEHICLE SENSOR CIRCUIT BETWEEN IN-VEHICLE SENSOR AND AUTO AMP. (LCU)
Disconnect auto amp. (LCU) harness connector.
OK or NG
OK >> 1. Replace auto amp. (LCU).
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and
perform self-diagnosis STEP-2.Confirm that code No.
20 is displayed.
NG >> Repair harness or connector.
COMPONENT INSPECTION
In-vehicle Sensor
After disconnecting in-vehicle sensor harness connector, measure
resistance between terminals 1 and 2 at sensor harness side, using
the table below.
If NG, replace in-vehicle sensor.
Terminals
Continuity
ConnectorTerminal (Wire
color)ConnectorTerminal (Wire
color)
M34 1 (P) M52 8 (P) Yes
RJIA0561E
Temperature °C (°F) Resistance kΩ
-15 (5) 12.73
-10 (14) 9.92
-5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
RJIA0562E
Page 3381 of 3833

TROUBLE DIAGNOSIS
ATC-105
C
D
E
F
G
H
I
K
L
MA
B
AT C
Sunload Sensor CircuitEJS001HD
COMPONENT DESCRIPTION
The sunload sensor is located on the left defroster grille. It detects
sunload entering through windshield by means of a photo diode. The
sensor converts the sunload into a current value which is then input
into the auto amplifier.
SUNLOAD INPUT PROCESS
The auto amp. also includes a processing circuit which averages the variations in detected sunload over a
period of time. This prevents drastic swings in the ATC system operation due to small or quick variations in
detected sunload.
For example, consider driving along a road bordered by an occasional group of large trees. The sunload
detected by the sun-load sensor will vary whenever the trees obstruct the sunlight. The processing circuit
averages the detected sun-load over a period of time, so that the (insignificant) effect of the trees momentarily
obstructing the sunlight does not cause any change in the ATC system operation. On the other hand, shortly
after entering a long tunnel, the system will recognize the change in sun-load, and the system will react
accordingly.
DIAGNOSTIC PROCEDURE
SYMPTOM: Sunload sensor circuit is open or shorted. (25 or -25) is
indicated on auto amp. as a result of conducting Self-diagnosis
STEP 2.)
1.CHECK SUN-LOAD SENSOR CIRCUIT BETWEEN SUNLOAD SENSOR AND GROUND
Disconnect sunload sensor harness connector.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA0050E
SHA601F
Te r m i n a l s
Voltage (+)
(-)
ConnectorTe r m i n a l ( W i r e
color)
M74 1 (OR) Ground Approx. 5V
RJIA0563E
Page 3382 of 3833

ATC-106
TROUBLE DIAGNOSIS
2. CHECK SUNLOAD SENSOR CIRCUIT BETWEEN SUNLOAD SENSOR AND AUTO AMP. (LCU)
Disconnect auto amp. (LCU) harness connector.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK SUNLOAD SENSOR.
Refer to ATC-107, "
Sunload Sensor" .
OK or NG
OK >> 1. Replace auto amp. (LCU).
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and perform self-diagnosis STEP-2. Confirm
that code No. 20 is displayed.
NG >> 1. Replace sunload sensor.
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and perform self-diagnosis STEP-2. Confirm
that code No. 20 is displayed.
4. CHECK SUNLOAD SENSOR CIRCUIT BETWEEN SUNLOAD SENSOR AND AUTO AMP. (LCU)
Disconnect auto amp. (LCU) harness connector.
OK or NG
OK >> 1. Replace auto amp.
2. Go to self-diagnosis AT C - 4 7 , "
PROCEDURE" and
perform self-diagnosis STEP-2. Confirm that code
No. 20 is displayed.
NG >> Repair harness or connector.
Terminals
Continuity
ConnectorTerminal (Wire
color)ConnectorTerminal (Wire
color)
M74 2 (B/Y) M53 24 (B/Y) Yes
RJIA0564E
Terminals
Continuity
ConnectorTerminal (Wire
color)ConnectorTerminal
(Wirecolor)
M74 1 (OR) M52 10(OR) Yes
RJIA0565E
Page 3383 of 3833
TROUBLE DIAGNOSIS
ATC-107
C
D
E
F
G
H
I
K
L
MA
B
AT C
COMPONENT INSPECTION
Sunload Sensor
Measure voltage between auto amp. terminal 10 and ground.
If NG, replace auto amp.
●When checking sunload sensor, select a place where sun shines directly on it.
RJIA0566E
SHA930E
Page 3384 of 3833
ATC-108
TROUBLE DIAGNOSIS
Intake Sensor Circuit
EJS001HE
COMPONENT DESCRIPTION
Intake Sensor
The intake sensor is located on the heater & cooling unit. It converts
temperature of air after it passes through the evaporator into a resis-
tance value which is then input to the auto amp.
After disconnecting intake sensor harness connector, measure resis-
tance between terminals 1 and 2 at sensor harness side, using the
table below.
If NG, replace intake sensor.
DIAGNOSTIC PROCEDURE
SYMPTOM: Intake sensor circuit is open or shorted. (24 or -24) is
indicated on auto amp. as a result of conducting Self-diagnosis
STEP 2.)
Temperature °C (°F)Resistance kΩ
With gasoline engine With diesel engine
-15 (5) 12.34 18.63
-10 (14) 9.62 14.15
-5 (23) 7.56 10.86
0 (32) 6.00 8.41
5 (41) 4.80 6.58
10 (50) 3.87 5.19
15 (59) 3.15 4.12
20 (68) 2.57 3.30
25 (77) 2.12 2.67
30 (86) 1.76 2.17
35 (95) 1.47 1.78
40 (104) 1.23 1.46
45 (113) 1.04 1.21
RJIA0051E
RJIA0567E