Page 3505 of 4179

TROUBLE DIAGNOSIS
ATC-109
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AT C
Ambient Sensor CircuitEJS004YP
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the hood lock stay. It detects
ambient temperature and converts it into a resistance value which is
then input into the auto amp.
AMBIENT TEMPERATURE INPUT PROCESS
The auto amp. includes a processing circuit for the ambient sensor input. However, when the temperature
detected by the ambient sensor increases quickly, the processing circuit retards the auto amp. function. It only
allows the auto amp. to recognize an ambient temperature increase of 0.33°C (0.6°F) per 100 seconds.
As an example, consider stopping for a few minutes after high speed driving. Although the actual ambient tem-
perature has not changed, the temperature detected by the ambient sensor will increase. This is because the
heat from the engine compartment can radiate to the front grille area, location of the ambient sensor.
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted.
LED of A/C switch does not illuminate as a result of performing self-
diagnosis STEP-2.
1. CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E38
terminal 1 (R/B) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA0048E
RHA051GD
1 – Ground : Approx. 5V
RJIA2017E
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ATC-110
TROUBLE DIAGNOSIS
2. CHECK CIRCUIT BETWEEN CONTINUITY AMBIENT SENSOR AND AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect auto amp. connector.
3. Check continuity between ambient sensor harness connector
E38 terminal 2 (B/Y) and auto amp. harness connector M53 ter-
minal 24 (B/Y).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK AMBIENT SENSOR
Refer to AT C - 111 , "
Ambient Sensor" .
OK or NG
OK >> 1. Replace auto amp.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
NG >> 1. Replace ambient sensor.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
4. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect auto amp. connector.
3. Check continuity between ambient sensor harness connector
E38 terminal 1 (R/B) and auto amp. harness connector M52 ter-
minal 9 (R/B).
4. Check continuity between ambient sensor harness counector
E38 terminal 1 (R/B) and auto amp. harness connector M52 ter-
minal 9 (R/B) and ground.
OK or NG
OK >> 1. Replace auto amp.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
NG >> Repair harness or connector.2 – 24 : Continuity should exist.
RJIA1951E
1 – 9 : Continuity should exist.
1 – Ground : Continuity not should exist.
RJIA2877E
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TROUBLE DIAGNOSIS
ATC-111
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AT C
COMPONENT INSPECTION
Ambient Sensor
After disconnecting ambient sensor connector E38, measure resis-
tance between terminals 2 and 1 at sensor side, using the table
below.
If NG, replace ambient sensor.
In-vehicle Sensor CircuitEJS004YQ
COMPONENT DESCRIPTION
In-vehicle Sensor
The in-vehicle sensor is located on instrument driver lower panel. It
converts variations in temperature of compartment air drawn from
the aspirator into a resistance value. It is then input into the auto
amp.
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
SJIA0433E
RJIA2841E
RJIA0557E
Page 3508 of 4179
ATC-112
TROUBLE DIAGNOSIS
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: In-vehicle sensor circuit is open or shorted.
LED of A/C switch does not illuminate as a result of performing self-
diagnosis STEP-2.
1. CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND
1. Disconnect in-vehicle sensor connector.
2. Turn ignition switch ON.
3. Check voltage between in-vehicle sensor harness connector
M34 terminal 1 (P) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect auto amp. connector.
3. Check continuity between in-vehicle sensor harness connector
M34 terminal 2 (B/Y) and auto amp. harness connector M53 ter-
minal 24 (B/Y).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
RJIA1402E
RJIA0745E
1 – Ground : Approx. 5V
RJIA2022E
2 – 24 : Continuity should exist.
SJIA0434E
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TROUBLE DIAGNOSIS
ATC-113
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AT C
3. CHECK IN-VEHICLE SENSOR
Refer to AT C - 11 3 , "
In-vehicle Sensor" .
OK or NG
OK >> 1. Replace auto amp.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
NG >> 1. Replace in-vehicle sensor.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
4. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect auto amp. connector.
3. Check continuity between in-vehicle sensor harness connector
M34 terminal 1 (P) and auto amp. harness connector M52 termi-
nal 8 (P).
4. Check continuity between in-vhicle sensor harness connector
M34 terminal 1 (P) and ground.
OK or NG
OK >> 1. Replace auto amp.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
NG >> Repair harness or connector.
COMPONENT INSPECTION
In-vehicle Sensor
After disconnecting in-vehicle sensor connector M34, measure resis-
tance between terminals 1 and 2 at sensor side, using the table
below.
If NG, replace in-vehicle sensor.1 – 8 : Continuity should exist.
1 – Ground : Continuity not should exist.
SJIA0456E
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
SJIA0436E
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ATC-114
TROUBLE DIAGNOSIS
Sunload Sensor CircuitEJS004YR
COMPONENT DESCRIPTION
The sunload sensor is located on the defroster grille (left side). 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 amp.
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 sunload sensor will vary whenever the trees obstruct the sunlight. The processing circuit aver-
ages the detected sunload 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 sunload, and the system will react accord-
ingly.
DIAGNOSTIC PROCEDURE FOR SUNLOAD SENSOR
SYMPTOM: Sunload sensor circuit is open or shorted.
LED of A/C switch does not illuminate as a result of performing self-
diagnosis STEP-2.
1. CHECK VOLTAGE BETWEEN SUNLOAD SENSOR AND GROUND
1. Disconnect sunload sensor connector.
2. Turn ignition switch ON.
3. Check voltage between sunload sensor harness connector M74
terminal 1 (OR) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA0050E
SHA601F
1 – Ground : Approx. 5V
RJIA2027E
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TROUBLE DIAGNOSIS
ATC-115
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AT C
2. CHECK CIRCUIT CONTINUITY BETWEEN SUNLOAD SENSOR AND AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect auto amp. connector.
3. Check continuity between sunload sensor harness connector
M74 terminal 2 (B/Y) and auto amp. harness connector M53 ter-
minal 24 (B/Y).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK SUNLOAD SENSOR.
1. Reconnect sunload sensor connector and auto amp. connector.
2. Refer to AT C - 11 6 , "
Sunload Sensor" .
OK or NG
OK >> 1. Replace auto amp.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
NG >> 1. Replace sunload sensor.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
4. CHECK CIRCUIT CONTINUITY BETWEEN SUNLOAD SENSOR AND AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect auto amp. connector.
3. Check continuity between sunload sensor harness connector
M74 terminal 1 (OR) and auto amp. harness connector M52 ter-
minal 10 (OR).
4. Check continuity between sunload sensor harness connector
M74 terminal 1 (OR) and ground.
OK or NG
OK >> 1. Replace auto amp.
2. Go to self-diagnosis AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2.
NG >> Repair harness or connector.2 – 24 : Continuity should exist.
SJIA0437E
1 – 10 : Continuity should exist.
1 – Ground : Continuity not should exist.
RJIA2882E
Page 3512 of 4179
ATC-116
TROUBLE DIAGNOSIS
COMPONENT INSPECTION
Sunload Sensor
Measure voltage between auto amp. harness connector M52 termi-
nal 10 (OR) and ground.
If NG, replace sunload sensor.
When checking sunload sensor, select a place where sun shines directly on it.
RJIA0566E
SHA930E