air intake INFINITI FX35 2008 User Guide

TROUBLE DIAGNOSISATC-47
< SERVICE INFORMATION >
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10.CHECK IN-VEHICLE SENSOR
Press (DEF) switch for the second time. Temperature detected
by in-vehicle sensor is indicated on the display.
NOTE:
If the temperature indicated on the display greatly differs from the
actual temperature, check sensor circuit first, and then check sensor.
OK or NG
OK >> GO TO 11.
NG >> Go to In-vehicle Sensor Circuit. Refer to ATC-88, "
In-
vehicle Sensor Circuit".
11 .CHECK INTAKE SENSOR
Press (DEF) switch for the third time. Temperature detected by
intake sensor is indicated on the display.
NOTE:
If the temperature indicated on the display greatly differs from the
actual temperature, check sensor circuit first, and then check sensor.
OK or NG
OK >> GO TO 12.
NG >> Go to Intake Sensor Circuit. Refer to ATC-94, "
Intake
Sensor Circuit".
12.CHECK CAN COMMUNICATION ERROR
1. Press intake switch.
2. CAN communication error between the unified meter and A/C amp. and the display control unit can be detected as self-diag-
nosis results. (If plural errors occur, the display of each error will
blink twice for 0.5 second intervals.)
OK or NG
OK >> 1. Turn ignition switch OFF or AUTO switch ON. 2. INSPECTION END
NG >> Go to CAN communication. Refer to BCS-11, "
CON-
SULT-III Function (BCM)".
 Unified meter and A/C amp. - Display control unit
13.CHECK MALFUNCTIONING SENSOR AND DOOR MOTOR
Refer to the following chart for malfunctioning code No.
(If two or more sensors and door motors malfuncti on, corresponding code Nos. indicates 1 second each.)
*1: Perform self-diagnosis STEP-2 under sunshine.
PJIA0152E
PJIA0153E
SJIA1611E
Code No. Malfunctioning sensor and door motor (Including circuits) Reference page 21 / −21 Ambient sensor ATC-86, "
Ambient Sensor Circuit"
22 / −22 In-vehicle sensor AT C - 8 8 , "In-vehicle Sensor Circuit"
24 / −24 Intake sensor AT C - 9 4 , "Intake Sensor Circuit"
25 / −25
Sunload sensor*1AT C - 9 1 , "Sunload Sensor Circuit"
26 / −26 Air mix door motor PBR (Driver side)
AT C - 6 2 , "Air Mix Door Motor PBR Circuit"27 / −27 Air mix door motor PBR (Passenger side)
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-51
< SERVICE INFORMATION >
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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 che cking blower speed and fan symbol until all speeds are
checked.
3. Leave blower on max. speed.
If NG, go to trouble diagnosis procedure for ATC-64, "
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 ATC-29, "
Discharge Air Flow".
If NG, go to trouble diagnosis procedure for ATC-57, "
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 FRE when the D/F or DEF
is selected.
CHECKING INTAKE AIR
1. Press intake switch. Recirculation indicator should illuminate.
2. Press intake switch again. Fresh indicator should illuminate.
3. Listen for intake door position change. (S light change of blower sound can be heard.)
If NG, go to trouble diagnosis procedure for ATC-62, "
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 FRE
when the D/F or DEF is selected.
CHECKING TEMPERATURE DECREASE
1. Press temperature control (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 ATC-75, "
Insufficient Cooling".
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Press temperature control (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-82, "
Insufficient Heating".
If OK, continue the check.
CHECKING 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 ATC-69, "
Magnet Clutch Circuit".
If OK, continue the check.
CHECKING AUTO MODE
1. Press AUTO switch and A/C switch.
2. Display should indicate AUTO.  Confirm that discharge air and blower speed will depend on ambient, in-vehicle, and set temperatures.
If NG, go to trouble diagnosis procedure for ATC-52, "
Power Supply and Ground Circuit for Auto Amp", then if
necessary, trouble diagnosis procedure for ATC-69, "
Magnet Clutch Circuit".
SJIA0302E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-52
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
If all operational checks are OK (symptom cannot be duplicated), go to Incident Simulation Tests in GI-25,
"How to Perform Efficient Diagnosis for an Electrical Incident" and perform tests as outlined to simulate driving
conditions environment. If symptom appears, refer to ATC-32, "
How to Perform Trouble Diagnosis for Quick
and Accurate Repair" and perform applicable trouble diagnosis procedures.
Power Supply and Ground Circuit for Auto AmpINFOID:0000000001328183
SYMPTOM: A/C system does not activate.
INSPECTION FLOW
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.
When the various switches and temperature control switch are oper-
ated, data is input to the unified meter and A/C amp. from the display
control unit using CAN communication.
Self-diagnosis 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)
*1 "DIAGNOSIS PROCEDURE FOR A/
C SYSTEM" *2
AT C - 5 0 , "Operational Check"*3AV- 7 9 , "Unable to Operate System
with A/C and AV Switch" (Without
navigation system) or AV- 1 2 7 , "
Un-
able to Operate System with A/C and
AV S w i t c h" (With navigation system)
SJIA1582E
SJIA1566E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-54
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
2. Check continuity between unified meter and A/C amp. harnessconnector M56 terminal 29, 30 and ground.
OK or NG
OK >> Replace unified meter and A/C amp.
NG >> Repair harness or connector.
LAN System CircuitINFOID:0000000001328184
SYMPTOM: Mode door motor, intake door motor and/or air mix door motor(s) does not operate normally.
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT
1.CHECK POWER SUPPLY FOR UNI FIED 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 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. 29, 30 – Ground : Continuity should exist.
RJIA1985E
RJIA1775E
54 – Ground : Battery voltage
RJIA1986E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-55
< SERVICE INFORMATION >
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Confirm A/C LAN signal between unified meter and A/C amp. har-
ness connector M57 terminal 43 and ground using an oscilloscope.
OK or NG
OK >> GO TO 3.
NG >> Replace unified meter and A/C amp.
3.CHECK POWER SUPPLY FOR EACH DOOR MOTOR
Check voltage between each door motor harness connector terminal
1 and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4.CHECK SIGNAL FOR EACH DOOR MOTOR
Confirm A/C LAN signal between each door motor harness connec-
tor terminal 3 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 each door motor connector.
Te r m i n a l s
Vo l ta g e
(+)
(− )
Unified meter and A/
C amp. connector Te r m i n a l N o .
M57 43 Ground
RJIA1987E
SJIA1453J
1 – Ground : Battery voltage
RJIA1988E
Door motor Te r m i n a l s
Vol tag e
(+)
(− )
Con-
nector Te r m i n a l
No.
Mode M258 3
Ground
Air mix
(Driver
side)
M252 3
Air mix
(Passen-
ger side) M257 3
Intake M253 3
RJIA1989E
SJIA1453J
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-56
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
3. Check continuity between each door motor harness connectorterminal 2 and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6.CHECK MOTOR OPERATION
1. Reconnect each door motor connector.
2. Turn ignition switch ON.
3. Confirm operation of each door motor.
OK or NG
OK >> (Return to operate normally.)  Poor contact in motor connector.
NG >> (Does not operate normally.) GO TO 7.
7.CHECK AIR MIX DOOR MOTOR AND INTAKE DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect mode, air mix (driver side, pass enger side), and intake door motor connectors.
3. Reconnect air mix (driver side, passenger side) and intake door motor connectors.
4. Turn ignition switch ON.
5. Confirm operation of air mix door motor (driver side, passenger side) and intake door motor.
OK or NG
OK >> [Air mix (driver side, passenger side) and intake door motors operate normally.]
 Replace mode door motor.
NG >> [Air mix (driver side, passenger side) and intake door motors does not operate normally.]
GO TO 8.
8.CHECK MODE DOOR MOTOR AND INTAKE DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (driver side, passenger side) connectors.
3. Reconnect mode door motor connector.
4. Turn ignition switch ON.
5. Confirm operation of mode door motor and intake door motor.
OK or NG
OK >> (Mode and intake door motors operate normally.)  GO TO 10.
NG >> (Mode and intake door motors does not operate normally.) GO TO 9.
9.CHECK MODE DOOR MOTOR AND AIR MIX DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect intake door motor connector.
3. Reconnect air mix door motor (driver side, passenger side) connectors.
4. Turn ignition switch ON.
5. Confirm operation of mode door motor and air mix door motor (driver side, passenger side).
OK or NG
OK >> [Mode and air mix door motor (driver side, passenger side) operate normally.]  Replace intake door motor.
NG >> [Mode and air mix door motor (driver side, passenger side) does not operate normally.]
 Replace display and A/C auto amp.
10.CHECK AIR MIX DOOR MOTOR OPERATION 2 – Ground : Continuity should exist.
RJIA1990E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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ATC-58
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
SYSTEM DESCRIPTION
Component Parts
Mode door control system components are:
 Unified meter and A/C amp.
 Mode door motor (LCU)
 A/C LAN system (PBR built-in mode door motor, air mix door motor and intake door motor)
 In-vehicle sensor
 Ambient sensor
 Sunload sensor
 Intake sensor
System Operation
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends air mix door, mode door and intake door opening angle data to the air mix door motor LCUs, mode door
motor LCU and intake door motor LCU.
The air mix door motors, mode 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 door motor with the existing decision and open-
ing angles. Subsequently, HOT/COLD, DEF/VENT and FRE/ REC operation is selected. The new selection
data are returned to the unified meter and A/C amp.
Mode Door Control Specification
*1 ATC-29, "Discharge Air Flow"*2AT C - 5 0 , "Operational Check"*3ATC-43, "Self-Diagnosis Function",
see No. 4 to 6.
*4 ATC-86, "
Ambient Sensor Circuit"*5AT C - 8 8 , "In-vehicle Sensor Circuit"*6ATC-91, "Sunload Sensor Circuit"
*7 ATC-94, "Intake Sensor Circuit"*8AT C - 5 9 , "Air Mix Door Motor Circuit"*9ATC-43, "Self-Diagnosis Function",
see No. 13.
*10 ATC-54, "
LAN System Circuit"*11AT C - 11 3*12ATC-32, "How to Perform Trouble Di-
agnosis for Quick and Accurate Re-
pair"
SJIA1585E
RJIA1778E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-60
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
SYSTEM DESCRIPTION
Component Parts
Air mix door control system components are:
 Unified meter and A/C amp.
 Air mix door motor (LCU)
 A/C LAN system (PBR built-in mode door motor, air mix door motor and intake door motor)
 In-vehicle sensor
 Ambient sensor
*1AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6. *2
AT C - 8 6 , "Ambient Sensor Circuit"*3 AT C - 8 8 , "In-vehicle Sensor Circuit"
*4AT C - 9 1 , "Sunload Sensor Circuit"*5AT C - 6 2 , "Air Mix Door Motor PBR
Circuit"
*6 AT C - 4 3 , "Self-Diagnosis Function",
see No. 13.
*7 AT C - 5 4 , "
LAN System Circuit".*8 AT C - 5 0 , "Operational Check"*9AT C - 3 2 , "How to Perform Trouble
Diagnosis for Quick and Accurate
Repair"
*10AT C - 9 4 , "Intake Sensor Circuit"
SJIA1586E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISATC-61
< SERVICE INFORMATION >
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 Sunload sensor
 Intake sensor
System Operation
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends air mix door, mode door and intake door motor opening angle data to the air mix door motor LCUs,
mode door motor LCU and intake door motor LCU.
The air mix door motors, mode door motor and intake door motor read their respective signals according to the
address signal. Opening angle indication signals receiv ed from the unified meter and A/C amp. and each of
the motor position sensors are compared by the LCUs in each door motor with the existing decision and open-
ing angles. Subsequently, HOT/COLD, DEF/VENT and FRE/REC operation is selected. The new selection
data are returned to the unified meter and A/C amp.
Air Mix Door Control Specification
COMPONENT DESCRIPTION
Air Mix Door Motor
The air mix door motors are attached to the heater & cooling unit
assembly. It rotates so that the air mix door is opened or closed to a
position set by the unified meter and A/C amp. Motor rotation is then
conveyed through a shaft and the air mix door position feedback is
then sent to the unified meter and A/C amp. by PBR built-in air mix
door motor.
RJIA1781E
RJIA1782E
RJIA0893E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

ATC-62
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR
SYMPTOM: Discharge air temperature does not change.
Perform diagnosis procedure. Refer to ATC-54, "
LAN System Circuit".
Air Mix Door Motor PBR CircuitINFOID:0000000001328187
SYMPTOM
 Discharge air temperature does not change.
 PBR circuit is open or shorted.
DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR PBR
Perform diagnosis procedure. Refer to ATC-54, "LAN System Circuit".
Intake Door Motor CircuitINFOID:0000000001328188
SYMPTOM Intake door does not change.
 Intake door motor does not operate normally.
INSPECTION FLOW
RJIA0894E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C