INFINITI FX35 2005 Service Manual

ATC-104
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Ambient Sensor CircuitAJS00154
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 unified meter and A/C amp.
AMBIENT TEMPERATURE INPUT PROCESS
The unified meter and A/C 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 unified meter
and A/C amp. function. It only allows the unified meter and A/C 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.
DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. (21 or −21 is
indicated on unified meter and A/C amp. 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 E34 terminal 1 (Y) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA2016E
RJIA1461E
1 – Ground : Approx. 5 V
RJIA2017E

TROUBLE DIAGNOSIS ATC-105
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AT C
Revision: 2005 July 2005 FX
2. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between ambient sensor harness connector E34 terminal 2 (W) and unified meter and A/C amp. harness
connector M57 terminal 49 (W/G).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK AMBIENT SENSOR
Refer to ATC-106, "
Ambient Sensor" .
OK or NG
OK >> 1. Replace unified meter and A/C amp. 2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION 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 - 5 4 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
4. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between ambient sensor harness connector E34 terminal 1 (Y) and unified meter and A/C amp. harness con-
nector M57 terminal 39 (Y).
4. Check continuity between ambient sensor harness connector E34 terminal 1 (Y) and ground.
OK or NG
OK >> 1. Replace unified meter and A/C amp. 2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
NG >> Repair harness or connector. 2 – 49 : Continuity should exist.
RJIA2018E
1 – 39 : Continuity should exist.
1 – Ground : Continuity should not exist.
RJIA2019E

ATC-106
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
COMPONENT INSPECTION
Ambient Sensor
After disconnecting ambient sensor connector E34, measure resis-
tance between terminals 1 and 2 at sensor side, using the table
below.
If NG, replace ambient sensor.
Temperature °C ( °F) Resistance k Ω
− 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
RJIA2020E

TROUBLE DIAGNOSIS ATC-107
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AT C
Revision: 2005 July 2005 FX
In-vehicle Sensor CircuitAJS00155
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 unified
meter and A/C amp.
Aspirator
The aspirator is located on driver’s side of heater & cooling unit. It
produces vacuum pressure due to air discharged from the heater &
cooling unit, continuously taking compartment air in the aspirator.
RJIA2021E
RJIA0921E
RJIA1804E

ATC-108
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: In-vehicle sensor circuit is open or shorted. (22 or −22 is
indicated on unified meter and A/C amp. 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 M46 terminal 1 (BR/W) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND UNIFIED METER AND A/C
AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between in-vehicle sensor harness connector M46 terminal 2 (W/G) and unified meter and A/C amp. harness
connector M57 terminal 49 (W/G).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK IN-VEHICLE SENSOR
Refer to ATC-109, "
In-vehicle Sensor" .
OK or NG
OK >> 1. Replace unified meter and A/C amp. 2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION 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 - 5 4 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
RJIA1452E
1 – Ground : Approx. 5 V
RJIA2022E
2 – 49 : Continuity should exist.
RJIA2023E

TROUBLE DIAGNOSIS ATC-109
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AT C
Revision: 2005 July 2005 FX
4. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND UNIFIED METER AND A/C
AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between in-vehicle sensor harness connector M46 terminal 1 (BR/W) and unified meter and A/C amp. harness
connector M57 terminal 40 (BR/W).
4. Check continuity between in-vehicle sensor harness connector M46 terminal 1 (BR/W) and ground.
OK or NG
OK >> 1. Replace unified meter and A/C amp. 2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION 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 connector M46, measure resis-
tance between terminals 1 and 2 at sensor side, using the table
below.
If NG, replace in-vehicle sensor. 1 – 40 : Continuity should exist.
1 – Ground : Continuity should not exist.
RJIA2024E
Temperature °C ( °F) Resistance k Ω
− 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
RJIA2025E

ATC-110
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Sunload Sensor CircuitAJS00156
COMPONENT DESCRIPTION
Sunload Sensor
The sunload sensor is located on the passenger’s side front
defroster grille. It detects sunload entering through windshield by
means of a photo diode. The sensor converts the sunload into a cur-
rent value which is then input into the unified meter and A/C amp.
SUNLOAD INPUT PROCESS
The unified meter and A/C 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.
DIAGNOSIS PROCEDURE FOR SUNLOAD SENSOR
SYMPTOM: Sunload sensor circuit is open or shorted. (25 or −25 is
indicated on unified meter and A/C amp. 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 M87 terminal 1 (LG) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA2026E
RJIA1455E
1 – Ground : Approx. 5 V
RJIA2027E

TROUBLE DIAGNOSIS ATC-111
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AT C
Revision: 2005 July 2005 FX
2. CHECK CIRCUIT CONTINUITY BETWEEN SUNLOAD SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between sunload sensor harness connector M87 terminal 2 (W/G) and unified meter and A/C amp. harness
connector M57 terminal 49 (W/G).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK SUNLOAD SENSOR
1. Reconnect sunload sensor connector and unified meter and A/C amp. connector.
2. Refer to AT C - 11 2 , "
Sunload Sensor" .
OK or NG
OK >> 1. Replace unified meter and A/C amp.
2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION 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 - 5 4 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
4. CHECK CIRCUIT CONTINUITY BETWEEN SUNLOAD SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between sunload sensor harness connector M87 terminal 1 (LG) and unified meter and A/C amp. harness
connector M57 terminal 50 (LG).
4. Check continuity between sunload sensor harness connector M87 terminal 1 (LG) and ground.
OK or NG
OK >> 1. Replace unified meter and A/C amp. 2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
NG >> Repair harness or connector. 2 – 49 : Continuity should exist.
RJIA2028E
1 – 50 : Continuity should exist.
1 – Ground : Continuity should not exist.
RJIA2029E

ATC-112
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
COMPONENT INSPECTION
Sunload Sensor
Measure voltage between unified meter and A/C amp. harness con-
nector M57 terminal 50 (LG) and ground.

When checking sunload sensor, select a place where sun shines directly on it.
If NG, replace sunload sensor.
RJIA2030E
SHA930E

TROUBLE DIAGNOSIS ATC-113
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AT C
Revision: 2005 July 2005 FX
Intake Sensor CircuitAJS00157
COMPONENT DESCRIPTION
Intake Sensor
The intake sensor is located on the heater & cooling unit assembly. It
converts temperature of air after it passes through the evaporator
into a resistance value which is then input to the unified meter and A/
C amp.
DIAGNOSIS PROCEDURE FOR INTAKE SENSOR
SYMPTOM: Intake sensor circuit is open or shorted. (24 or −24 is
indicated on unified meter and A/C amp. as a result of performing
self-diagnosis STEP-2.)
1. CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND
1. Disconnect intake sensor connector.
2. Turn ignition switch ON.
3. Check voltage between intake sensor harness connector M254 terminal 2 (R) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2. CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between intake sensor harness connector M254 terminal 1 (W) and unified meter and A/C amp. harness
connector M57 terminal 49 (W/G).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
RJIA0928E
RJIA1458E
2 – Ground : Approx. 5 V
RJIA2031E
1 – 49 : Continuity should exist.
RJIA2032E