drive INFINITI FX35 2004 Service Manual

ATC-30
AIR CONDITIONER CONTROL
Revision: 2004 November 2004 FX35/FX45
AIR CONDITIONER CONTROLPFP:27500
Description of Air Conditioner LAN Control SystemAJS0014A
The LAN (Local Area Network) system consists of unified meter and A/C amp., mode door motor, air mix door
motor and intake door motor.
A configuration of these components is shown in the diagram below.
System ConstructionAJS0014B
A small network is constructed between the unified meter and A/C amp., air mix door motor, mode door motor
and intake door motor. The unified meter and A/C amp. and motors are connected by data transmission lines
and motor power supply lines. The LAN network is built through the ground circuits of the each door motor.
Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted
through the data transmission lines connecting the unified meter and A/C amp. and each door motor.
The following functions are contained in LCUs built into the air mix door motor, mode door motor and intake
door motor.

Address

Motor opening angle signals

Data transmission

Motor stop and drive decision

Opening angle sensor (PBR function)

Comparison

Decision (Unified meter and A/C amp. indicated value and motor opening angle comparison)
OPERATION
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends mode door, air mix door and intake door opening angle data to the mode door motor LCU, air mix door
motor LCU and intake door motor LCU.
The mode door motor, air mix door motor and intake door motor read their respective signals according to the
address signal. Opening angle indication signals received from the unified meter and A/C amp. and each of
the motor position sensors are compared by the LCUs in each motor with the existing decision and opening
angles. Subsequently, HOT/COLD, DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The
new selection data is returned to the unified meter and A/C amp.
SJIA0262E
RJIA1747E

AIR CONDITIONER CONTROL
ATC-35
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Revision: 2004 November 2004 FX35/FX45
DISPLAY SCREEN
Displays the operational status of the system.
AUTO SWITCH

The compressor, intake doors, air mix doors, outlet doors and blower speed are automatically controlled
so that the in-vehicle temperature will reach, and be maintained at the set temperature selected by the
operator.

When pressing AUTO switch, air inlet, air outlet, fan speed, and discharge air temperature are automati-
cally controlled.
TEMPERATURE SWITCH (POTENTIO TEMPERATURE CONTROL) (DRIVER SIDE)
Increases or decreases the set temperature.
TEMPERATURE SWITCH (POTENTIO TEMPERATURE CONTROL) (PASSENGER SIDE)

Increases or decreases the set temperature.

When the temperature switch is pressed, the dual switch indicator will automatically illuminate.
RECIRCULATION (REC) SWITCH

When REC switch is ON, REC switch indicator turns ON, and air inlet is fixed to REC.

When REC switch is ON and is pressed for approximately 1.5 seconds or longer, REC and FRE switch
indicators blink twice. Then, automatic control mode is entered. Inlet status is displayed even during auto-
matically controlled.

When FRE switch is turned ON, or when compressor is turned from ON to OFF, REC switch is automati-
cally turned OFF (fixed to FRE mode). REC mode can be re-entered by pressing REC switch again.

REC switch is not operated when DEF switch is turned ON, or at the D/F position.
FRESH (FRE) SWITCH

When FRE switch is ON, FRE switch indicator turns ON, and air inlet is fixed to FRE.

When FRE switch is ON and is pressed for approximately 1.5 seconds or longer, REC and FRE switch
indicators blink twice. Then, automatic control mode is entered. Inlet status is displayed even during auto-
matically controlled.

When REC switch is turned ON, FRE switch is automatically turned OFF (fixed to REC mode). FRE mode
can be re-entered by pressing FRE switch again.
DEFROSTER (DEF) SWITCH
Positions the air outlet doors to the defrost position. Also positions the intake doors to the fresh air position.
REAR WINDOW DEFOGGER SWITCH
When illumination is ON, rear window is defogged.
OFF SWITCH
The compressor and blower are OFF, the intake doors are set to the fresh air position, and the air outlet doors
are set to the foot (75% foot and 25% defrost) position.
A/C SWITCH
The compressor is ON or OFF.
(Pressing the A/C switch when the AUTO switch is ON will turn off the A/C switch and compressor.)
MODE SWITCH
Controls the air discharge outlets.
FAN SWITCH
Manually control the blower speed. Seven speeds are available for manual control (as shown on the display
screen).
DUAL SWITCH (WITH LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CON-
TROL SYSTEM)

When the DUAL switch indicator is not illuminated and the DUAL switch is pressed, the driver-side setting
temperature and passenger-side setting temperature can each be set independently.

When the DUAL switch indicator is illuminated and the DUAL switch is pressed, the driver-side setting
temperature are applied to both sides.

TROUBLE DIAGNOSIS
ATC-53
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Revision: 2004 November 2004 FX35/FX45
Self-diagnosis FunctionAJS0014P
DESCRIPTION
The self-diagnostic system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to appli-
cable sections (items) for details. Shifting from usual control to the self-diagnostic system is accomplished by
starting the engine (turning the ignition switch ON) and pressing OFF switch for at least 5 seconds. The OFF
switch must be pressed within 10 seconds after starting the engine (ignition switch is turned ON). This system
will be canceled by either pressing AUTO switch or turning the ignition switch OFF. Shifting from one step to
another is accomplished by means of pressing temperature switch (driver side), as required.
Additionally shifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of pressing (fan)
UP switch.
RJIA1967E

ATC-54
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
FUNCTION CONFIRMATION PROCEDURE
1. SET IN SELF-DIAGNOSTIC MODE
1. Turn ignition switch ON.
2. Set in self-diagnostic mode as follows. Within 10 seconds after starting engine (ignition switch is turned
ON.), press OFF switch for at least 5 seconds.
CAUTION:

If battery voltage drops below 12V during diagnosis STEP-3, actuator speed becomes slower and
as a result, the system may generate an error even when operation is usual. To avoid this, start
engine before performing this diagnosis.

Former STEP-1 (LEDs and display screen are checked) does not exist in this self-diagnosis func-
tion.
>> GO TO 2.
2. STEP-2: SENSOR CIRCUITS ARE CHECKED FOR OPEN OR SHORT CIRCUIT
Does code No. 20 appear on the display?
YES >> GO TO 3.
NO >> GO TO 13.
3. CHECK TO ADVANCE SELF-DIAGNOSIS STEP-3
Press temperature (UP) switch (driver side).
Advance to self
-diagnosis STEP-3?
YES >> GO TO 4.
NO >> Malfunctioning OFF switch or unified meter and A/C amp. Refer to ATC-102, "
Self-diagnosis" .
4. CHECK TO RETURN SELF-DIAGNOSIS STEP-2
Press temperature (DOWN) switch (driver side).
Return to self
-diagnosis STEP-2?
YES >> GO TO 5.
NO >> Replace A/C and AV switch. Temperature switch malfunctions.
5. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED
Press temperature (UP) switch (driver side).
Does code No. 30 appear on the display?
YES >> GO TO 6.
NO >> GO TO 14.
RJIA0219E
RJIA0220E

TROUBLE DIAGNOSIS
ATC-55
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Revision: 2004 November 2004 FX35/FX45
6. STEP-4: OPERATION OF EACH DOOR MOTOR IS CHECKED
1. Press temperature (UP) switch (driver side).
2. Press (DEF) switch. Code No. of each door motor test is
indicated on the display.
>> GO TO 7.
7. CHECK ACTUATORS
Refer to the following chart and confirm discharge air flow, air tem-
perature, blower motor voltage and compressor operation.
Checks must be made visually, by listening to any noise, or by touching air outlets with your hand, etc. for
improper operation.
*1: FOOT position during automatic control. Refer to AT C - 6 0 , "
AUXILIARY MECHANISM: FOOT POSITION
SETTING TRIMMER" .
OK or NG
OK >> GO TO 8.
NG >>

Air outlet does not change.
Go to Mode Door Motor Circuit. Refer to AT C - 7 0 , "
Mode Door Motor Circuit" .

Intake door does not change.
Go to Intake Door Motor Circuit. Refer to AT C - 7 6 , "
Intake Door Motor Circuit" .

Blower motor operation is malfunctioning.
Go to Blower Motor Circuit. Refer to AT C - 7 9 , "
Blower Motor Circuit" .

Magnet clutch does not engage.
Go to Magnet Clutch Circuit. Refer to AT C - 8 4 , "
Magnet Clutch Circuit" .

Discharge air temperature does not change.
Go to Air Mix Door Motor Circuit. Refer to AT C - 7 3 , "
Air Mix Door Motor Circuit" .
RJIA1968E
SJIA0302E
41 42 43 44 45 46
Mode door position VENT B/L 1 B/L 2 FOOT*1 D/F DEF
Intake door position REC REC 20%FRE FRE FRE FRE
Air mix door position FULL COLD FULL COLD FULL HOT FULL HOT FULL HOT FULL HOT
Blower fan duty ratio 37% 91% 65% 65% 65% 91%
Compressor ON ON OFF OFF ON ON
Electronic control
valve (ECV) duty
ratio100% 100% 0% 0% 50% 100%

ATC-56
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
8. STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED
1. Press temperature (UP) switch (driver side).
2. Code No. 51 appears on the display.
>> GO TO 9.
9. CHECK AMBIENT SENSOR
Press (DEF) switch one time. Temperature detected by ambient
sensor is indicated on the display.
NOTE:
If temperature shown on display greatly differs from actual tempera-
ture, check sensor circuit first, then inspect sensor.
OK or NG
OK >> GO TO 10.
NG >> Go to Ambient Sensor Circuit. Refer to ATC-104, "
Ambi-
ent Sensor Circuit" .
10. CHECK IN-VEHICLE SENSOR
Press (DEF) switch a second time. Temperature detected by in-
vehicle sensor is indicated on the display.
NOTE:
If temperature shown on display greatly differs from actual tempera-
ture, check sensor circuit first, then inspect sensor.
OK or NG
OK >> GO TO 11.
NG >> Go to In-vehicle Sensor Circuit. Refer to ATC-107, "
In-
vehicle Sensor Circuit" .
11 . CHECK INTAKE SENSOR
Press (DEF) switch a third time. Temperature detected by intake
sensor is indicated on the display.
NOTE:
If temperature shown on display greatly differs from actual tempera-
ture, check sensor circuit first, then inspect sensor.
OK or NG
OK >> GO TO 12.
NG >> Go to Intake Sensor Circuit. Refer to AT C - 11 3 , "
Intake
Sensor Circuit" .
RJIA0223E
RJIA1271E
RJIA1272E

TROUBLE DIAGNOSIS
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Revision: 2004 November 2004 FX35/FX45
12. CHECK CAN COMMUNICATION ERROR
1. Press (REC) switch.
2. CAN communication error between unified meter and A/C amp.
and DISPLAY UNIT or DISPLAY C/U is detected.
OK or NG
OK >> 1. Turn ignition switch OFF or AUTO switch ON.
2. INSPECTION END
NG >> Go to CAN communication. Refer to BCS-14, "
CAN
Communication Inspection Using CONSULT-II (Self-
Diagnosis)" .

Unified meter and A/C amp. - DISPLAY UNIT

Unified meter and A/C amp. - DISPLAY C/U
13. CHECK MALFUNCTIONING SENSOR
Refer to the following chart for malfunctioning code No.
(If two or more sensors malfunction, corresponding code Nos. blink respectively twice.)
*1: Perform self-diagnosis STEP-2 under sunshine.
When performing indoors, aim a light (more than 60W) at sunload sensor, otherwise code No. 25 will indicate
despite that sunload sensor is functioning properly.
*2: ATC-104, "
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR" .
*3: ATC-108, "
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR" .
*4: AT C - 11 3 , "
DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR" .
*5: AT C - 11 0 , "
DIAGNOSTIC PROCEDURE FOR SUNLOAD SENSOR" .
*6: AT C - 6 6 , "
DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT" .
>> INSPECTION END
RJIA1969E
Code No. Malfunctioning sensor (Including circuits) Reference page
21 / −21 Ambient sensor *2
22 / −22 In-vehicle sensor *3
24 / −24 Intake sensor *4
25 / −25 Sunload sensor *1 *5
26 / −26 Air mix door motor PBR (Driver side)
*6
27 / −27 Air mix door motor PBR (Passenger side)
RJIA0227E

TROUBLE DIAGNOSIS
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Revision: 2004 November 2004 FX35/FX45
AUXILIARY MECHANISM: TEMPERATURE SETTING TRIMMER
The trimmer compensates for differences in range of ±3°C (±6°F) between temperature setting (displayed dig-
itally) and temperature felt by driver.
Operating procedures for this trimmer are as follows:
1. Begin Self-diagnosis STEP-5 mode. Refer to AT C - 5 3 , "
Self-diagnosis Function" .
2. Press (fan) UP switch to set system in auxiliary mode.
3. Display shows 61 in auxiliary mechanism. It takes approximately 3 seconds.
4. Press temperature switch (driver side) as desired. Temperature will change at a rate of 0.5°C (1.0°F) each
time a switch is pressed.
CAUTION:
A decimal point is not indicated when the display shows “°C”.
When battery cable is disconnected, trimmer operation is canceled. Temperature set becomes that of initial
condition, i.e. 0°C (0°F).
RJIA1970E

ATC-62
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
CHECKING RECIRCULATION
1. Press recirculation (REC) switch one time. Recirculation indica-
tor should illuminate.
2. Press fresh (FRE) switch one time. Fresh indicator should illumi-
nate.
3. Listen for intake door position change (you should hear blower
sound change slightly).
If NG, go to trouble diagnosis procedure for AT C - 7 6 , "
Intake Door
Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRESH when the DEF or D/F is selected.
CHECKING TEMPERATURE DECREASE
1. Press temperature (DOWN) switch (driver side) until 18°C
(60°F) is displayed.
2. Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for AT C - 9 1 , "
Insufficient
Cooling" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Press temperature (UP) switch (driver side) until 32°C (90°F) is
displayed.
2. Check for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for ATC-100, "
Insufficient
Heating" .
If OK, continue the check.
CHECK A/C SWITCH
1. Press AUTO switch and A/C switch.
2. A/C switch indicator will turn ON.

Confirm that the compressor clutch engages (sound or visual
inspection).
If NG, go to trouble diagnosis procedure for AT C - 8 4 , "
Magnet Clutch
Circuit" .
If OK, continue the check.
RJIA1978E
RJIA1976E
RJIA1977E
RJIA1975E

TROUBLE DIAGNOSIS
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Revision: 2004 November 2004 FX35/FX45
3. CHECK POWER SUPPLY FOR MOTOR
Check voltage between mode door motor harness connector M258
terminal 1 (G), driver side air mix door motor harness connector
M252 terminal 1 (G), passenger side air mix door motor harness
connector M257 terminal 1 (G), intake door motor harness connector
M253 terminal 1 (G) and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK SIGNAL FOR MOTOR
Confirm A/C LAN signal between mode door motor harness connec-
tor M258 terminal 3 (L), driver side air mix door motor harness con-
nector M252 terminal 3 (L), passenger side air mix door motor
harness connector M257 terminal 3 (L), intake door motor harness
connector M253 terminal 3 (G/B) and ground using an oscilloscope.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
5. CHECK MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect door motor connector.
3. Check continuity between mode door motor harness connector
M258 terminal 2 (B), driver side air mix door motor harness con-
nector M252 terminal 2 (B), passenger side air mix door motor
harness connector M257 terminal 2 (B), intake door motor har-
ness connector M253 terminal 2 (B) and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.1 – Ground : Battery voltage
RJIA1988E
Door motorTerminals
Voltage (+)
(−)
Con-
nectorTerminal
No.
(wire color)
Mode M258 3 (L)
Ground Air mix
(Driver
side)M252 3 (L)
Air mix
(Passen-
ger side)M257 3 (L)
Intake M253 3 (L)
RJIA1989E
HAK0652D
2 – Ground : Continuity should exist.
RJIA1990E