air INFINITI FX35 2004 Service Manual

TROUBLE DIAGNOSIS
ATC-55
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AT C
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%

TROUBLE DIAGNOSIS
ATC-57
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AT C
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
ATC-61
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Revision: 2004 November 2004 FX35/FX45
Operational CheckAJS0014Q
The purpose of the operational check is to confirm that the system operates properly.
CHECKING MEMORY FUNCTION
1. Set the temperature to 32°C (90°F).
2. Press OFF switch.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous tempera-
ture.
7. Press OFF switch.
If NG, go to trouble diagnosis procedure for ATC-103, "
Memory
Function" .
If OK, continue the check.
CHECKING BLOWER
1. Press fan (UP) switch. Blower should operate on low speed. The
fan symbol should have one blade lit.
2. Press fan (UP) switch again, and continue checking blower
speed and fan symbol until all speeds are checked.
3. Leave blower on MAX. speed.
If NG, go to trouble diagnosis procedure for AT C - 7 9 , "
Blower Motor
Circuit" .
If OK, continue the check.
CHECKING DISCHARGE AIR
1. Press MODE switch and DEF switch.
2. Each position indicator should change shape.
3. Confirm that discharge air comes out according to the air distri-
bution table. Refer to AT C - 3 7 , "
Discharge Air Flow" .
If NG, go to trouble diagnosis procedure for AT C - 7 0 , "
Mode 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.Conditions : Engine running at usual operating temperature
RJIA1972E
RJIA1973E
RJIA1974E
SJIA0302E

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
ATC-63
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AT C
Revision: 2004 November 2004 FX35/FX45
CHECKING AUTO MODE
1. Press AUTO switch and A/C switch.
2. Display should indicate AUTO.

Confirm that the compressor clutch engages (sound or visual
inspection). (Discharge air and blower speed will depend on
ambient, in-vehicle, and set temperatures.)
If NG, go to trouble diagnosis procedure for AT C - 6 3 , "
Power Supply
and Ground Circuit for Auto Amp." , then if necessary, trouble diag-
nosis procedure for AT C - 8 4 , "
Magnet Clutch Circuit" .
If all operational checks are OK (symptom cannot be duplicated), go
to malfunction Simulation Tests in GI-27, "
How to Perform Efficient
Diagnosis for an Electrical Incident" and perform tests as outlined to
simulate driving conditions environment. If symptom appears, refer
to AT C - 4 2 , "
SYMPTOM TABLE" and perform applicable trouble diagnosis procedures.
Power Supply and Ground Circuit for Auto Amp.AJS001BF
SYMPTOM: A/C system does not come on.
INSPECTION FLOW
RJIA1979E
*1AT C - 6 4 , "DIAGNOSTIC PROCE-
DURE FOR A/C SYSTEM".*2ATC-61, "
Operational Check".*3AV- 7 8 , "Trouble Diagnosis Chart by
Symptom".
*4AV- 8 4 , "
A/C and AV Switch Does Not
Operate".
RJIA1980E

ATC-64
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
COMPONENT DESCRIPTION
Unified Meter and A/C amp. (Automatic Amplifier)
The unified meter and A/C amp. has a built-in microcomputer which
processes information sent from various sensors needed for air con-
ditioner operation. The air mix door motor, mode door motor, intake
door motor, blower motor and compressor are then controlled.
The unified meter and A/C amp. is unitized with control mechanisms.
When the various switches and temperature switch are operated,
data is input to the unified meter and A/C amp. from the DISPLAY
UNIT/DISPLAY C/U using CAN communication.
Self-diagnostic functions are also built into unified meter and A/C
amp. to provide quick check of malfunctions in the auto air condi-
tioner system.
Potentio Temperature Control (PTC)
The PTC is built into the A/C and AV switch. It can be set at an inter-
val of 0.5°C (1.0°F) in the 18°C (60°F) to 32°C (90°F) temperature
range by pressing temperature switch. The set temperature is dis-
played.
DIAGNOSTIC PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not come on.
RJIA1965E
RJIA1982E
RJIA1983E

TROUBLE DIAGNOSIS
ATC-65
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Revision: 2004 November 2004 FX35/FX45
1. CHECK POWER SUPPLY CIRCUIT FOR UNIFIED METER AND A/C AMP.
1. Disconnect unified meter and A/C amp. connector.
2. Check voltage between unified meter and A/C amp. harness
connector M56 terminals 21 (R/W), 22 (G/R) and 35 (LG/R), uni-
fied meter and A/C amp. harness connector M57 terminal 46 (L/
W) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check 10A and 15A fuses [Nos. 6, 10, 11, 12 and 19, located in the fuse block (J/B)]. Refer to PG-
83, "FUSE BLOCK - JUNCTION BOX (J/B)" .

If fuses are OK, check harness for open circuit. Repair or replace if necessary.

If fuses are NG, replace fuse and check harness for short circuit. Repair or replace if necessary.
2. CHECK GROUND CIRCUIT FOR UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Check continuity between unified meter and A/C amp. harness
connector M56 terminal 29 (B), 30 (B) and ground.
OK or NG
OK >> Replace unified meter and A/C amp.
NG >> Repair harness or connector.
Terminals Ignition switch position
(+)
(-) OFF ACC ON Unified
meter and
A/C amp.
connectorTerminal No.
(wire color)
M56 21 (R/W)
GroundBattery
voltageBattery
voltageBattery
voltage
M56 22 (G/R) Approx. 0V Approx. 0VBattery
voltage
M56 35 (LG/R) Approx. 0VBattery
voltageBattery
voltage
M57 46 (L/W) Approx. 0VBattery
voltageBattery
voltage
RJIA1984E
29, 30 – Ground : Continuity should exist.
RJIA1985E

ATC-66
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
LAN System CircuitAJS0014S
SYMPTOM: Mode door motor, intake door motor and/or air mix door motor(s) does not operate normally.
DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT
1. CHECK POWER SUPPLY FOR UNIFIED METER AND A/C AMP.
1. Turn ignition switch ON.
2. Check voltage between unified meter and A/C amp. harness
connector M57 terminal 54 (Y/R) and ground.
OK or NG
OK >> GO TO 2.
NG >> Replace unified meter and A/C amp.
2. CHECK SIGNAL FOR UNIFIED METER AND A/C AMP.
Confirm A/C LAN signal between unified meter and A/C amp. har-
ness connector M57 terminal 43 (G/B) and ground using an oscillo-
scope.
OK or NG
OK >> GO TO 3.
NG >> Replace unified meter and A/C amp.
RJIA1775E
54 – Ground : Battery voltage
RJIA1986E
Terminals
Voltage (+)
(−)
Unified meter and A/
C amp. connectorTerminal No.
(wire color)
M57 43 (G/B) Ground
RJIA1987E
HAK0652D

TROUBLE DIAGNOSIS
ATC-67
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AT C
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

ATC-68
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
6. CHECK MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect each door motor connector.
3. Reconnect each door motor connector.
4. Turn ignition switch ON.
5. Confirm each door motor operation.
OK or NG
OK >> (Return to operate normally.)

Poor contact in motor connector.
NG >> (Does not operate normally.)

GO TO 7.
7. CHECK MODE DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect mode door motor and air mix door motor (driver side, passenger side) connector.
3. Reconnect mode door motor connector.
4. Turn ignition switch ON.
5. Confirm the mode door motor operation.
OK or NG
OK >> (Mode door motor operates normally.)

GO TO 8.
NG >> (Mode door motor does not operate normally.)

Repair mode door motor.
8. CHECK AIR MIX DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect mode door motor connector.
3. Reconnect air mix door motor connector (driver side, passenger side).
4. Turn ignition switch ON.
5. Confirm the air mix door motor operation.
OK or NG
OK >> (Air mix door motor operates normally.)

GO TO 9.
NG >> (Air mix door motor does not operate normally.)

GO TO 10.
9. CHECK INTAKE DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect air mix door motor connector (driver side, passenger side).
3. Reconnect intake door motor connector.
4. Turn ignition switch ON.
5. Confirm the intake door motor operation.
OK or NG
OK >> (Intake door motor operates normally.)

Repair unified meter and A/C amp.
NG >> (Intake door motor does not operate normally.)

Repair intake door motor.