2007 INFINITI M35 Blower motor

TROUBLE DIAGNOSIS
ATC-59
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AT C
Revision: 2007 April2007 M35/M45
Checks must be made visually, by listening the sound, or by touching air outlets with hand, etc. for improper
operation.
*1: FOOT position during automatic control. Refer to AT C - 6 4 , "
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 6 , "
Mode Door Motor Circuit" .

Upper ventilator outlet does not change.
Go to Upper Ventilator Door Motor Circuit. Refer to AT C - 7 9 , "
Upper Ventilator Door Motor Cir-
cuit" .

Intake door does not change.
Go to Intake Door Motor Circuit. Refer to AT C - 8 5 , "
Intake Door Motor Circuit" .

Discharge air temperature does not change.
Go to Air Mix Door Motor Circuit. Refer to AT C - 8 2 , "
Air Mix Door Motor Circuit" .

Blower motor operation is malfunctioning.
Go to Blower Motor Circuit. Refer to AT C - 8 8 , "
Blower Motor Circuit" .

Magnet clutch does not engage.
Go to Magnet Clutch Circuit. Refer to AT C - 9 3 , "
Magnet Clutch Circuit" .
8. STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED
1. Press temperature control (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 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 10.
NG >> Go to Ambient Sensor Circuit. Refer to AT C - 11 2 , "
Ambi-
ent Sensor Circuit" .
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 AT C - 11 5 , "
In-
vehicle Sensor Circuit" .
PJIA0151E
PJIA0152E

TROUBLE DIAGNOSIS
ATC-65
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AT C
Revision: 2007 April2007 M35/M45
Operational CheckNJS000GK
The purpose of the operational check is to check if the individual system operates properly.
CHECKING MEMORY FUNCTION
1. Press the temperature control (UP) switch (driver side) until 32°C (90°F) is displayed.
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 temperature.
7. Press OFF switch.
If NG, go to trouble diagnosis procedure for AT C - 111 , "
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 - 8 8 , "
Blower Motor Circuit" .
If OK, continue the check.
CHECKING DISCHARGE AIR (MODE SWITCH AND DEF SWITCH)
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 distribution table. Refer to AT C - 3 7 , "
Discharge
Air Flow" .
If NG, go to trouble diagnosis procedure for AT C - 7 6 , "
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 D/F or DEF is selected.Conditions : Engine running at normal operating temperature
RJIA4035E

ATC-66
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
CHECKING DISCHARGE AIR (UPPER VENT SWITCH)
1. Press temperature control (UP) switch (driver side) until 32°C (90°F) is displayed.
2. Press fan (UP:+) switch until Max. speed.
3. Set MODE switch (driver side) to VENT position.
4. Press UPPER VENT switch. AUTO indicator should illuminate.
5. Press temperature control (DOWN) switch (driver side) until 18°C (60°F) is displayed.
6. Confirm that discharger air come out.
7. Press UPPER VENT switch again. AUTO indicator should OFF.
If NG, go to trouble diagnosis procedure for AT C - 7 9 , "
Upper Ventilator Door Motor Circuit" .
If OK, continue the check.
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. (Slight change of blower sound can be heard.)
If NG, go to trouble diagnosis procedure for AT C - 8 5 , "
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 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 AT C - 9 8 , "
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-108, "
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 AT C - 9 3 , "
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 AT C - 6 7 , "
Power Supply and Ground Circuit for Auto Amp." , then
if necessary, trouble diagnosis procedure for AT C - 9 3 , "
Magnet Clutch Circuit" .
If all operational checks are OK (symptom cannot be duplicated), go to Incident Simulation Tests in GI-28,
"How to Perform Efficient Diagnosis for an Electrical Incident" and perform tests as outlined to simulate driv-
ing conditions environment. If symptom appears, refer to AT C - 4 1 , "
SYMPTOM TABLE" and perform applica-
ble trouble diagnosis procedures.

ATC-68
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
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, upper
ventilator door motor, intake door motor, blower motor and compres-
sor 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 AV
control unit / NAVI 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)
The PTC is built into the multifunction switch. It can be set at an
interval of 0.5°C (1.0°F) in the 18°C (60°F) to 32°C (90°F) tempera-
ture range by pressing temperature control switch. The set tempera-
ture is displayed.
DIAGNOSIS PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not come on.
RJIA4032E
RJIA4048E
RJIA4049E

TROUBLE DIAGNOSIS
ATC-87
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AT C
Revision: 2007 April2007 M35/M45
COMPONENT DESCRIPTION
Intake Door Motor
The intake door motor is attached to the blower unit. It rotates so that
air is drawn from inlets set by the unified meter and A/C amp. Motor
rotation is conveyed to a lever which activates the intake door.
DIAGNOSIS PROCEDURE FOR INTAKE DOOR MOTOR
SYMPTOM: Intake door motor does not operate normally.
Perform diagnosis procedure. Refer to AT C - 7 1 , "
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT" .
RJIA4068E

ATC-88
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Blower Motor CircuitNJS000GT
SYMPTOM: Blower motor operation is malfunctioning.
INSPECTION FLOW
*1AT C - 6 5 , "Operational Check"*2ATC-121, "Intake Sensor Circuit"*3AT C - 5 7 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2.
*4AT C - 5 7 , "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 6.*5ATC-57, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.*6AT C - 9 0 , "
DIAGNOSIS PROCE-
DURE FOR BLOWER MOTOR"
*7AT C - 4 1 , "SYMPTOM TABLE"*8ATC-112, "Ambient Sensor Circuit"*9AT C - 11 5 , "In-vehicle Sensor Circuit"
*10AT C - 11 8 , "Sunload Sensor Circuit"*11EC-214, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-926,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE)
RJIA4069E

TROUBLE DIAGNOSIS
ATC-89
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AT C
Revision: 2007 April2007 M35/M45
SYSTEM DESCRIPTION
Component Parts
Fan speed control system components are:

Unified meter and A/C amp.

A/C LAN system (PBR built-in mode door motor, upper ventilator door motor, air mix door motor and
intake door motor)

In-vehicle sensor

Ambient sensor

Sunload sensor

Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the unified meter and A/C amp. based on the
input from the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.
When the air flow is increased, the duty ratio of the blower fan motor’s drive signal is changed at 8%/sec. to
prevent a sudden increase in air flow.
In addition to manual air flow control and the usual automatic air flow control, starting air flow control, low
water temperature starting control and high passenger compartment temperature starting control are avail-
able.
RJIA4070E

ATC-90
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Starting Fan Speed Control
Start up from COLD SOAK Condition (Automatic mode)
In a cold start up condition where the engine coolant temperature is below 56°C (133°F), the blower will not
operate for a short period of time (up to 150 seconds). The exact start delay time varies depending on the
ambient and engine coolant temperature.
In the most extreme case (very low ambient) the blower starting delay will be 150 seconds as described
above. After this delay, the blower will operate at low speed until the engine coolant temperature rises above
56°C (133°F), and then the blower speed will increase to the objective speed.
Start up from usual or HOT SOAK Condition (Automatic mode)
The blower will begin operation momentarily after the AUTO switch is pressed. The blower speed will gradu-
ally rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
Blower Speed Compensation
Sunload
When the in-vehicle temperature and the set temperature are very close, the blower will be operating at low
speed. The low speed will vary depending on the sunload. During conditions of low or no sunload, the blower
speed is at duty ratio 25%. During high sunload conditions, the unified meter and A/C amp. raise the blower
speed (duty ratio 49%).
Fan Speed Control Specification
COMPONENT DESCRIPTION
Brush-less Motor
The blower motor utilizes a brush-less motor with a rotating magnet.
Quietness is improved over previous motors where the brush was
the point of contact and the coil rotated.
DIAGNOSIS PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning.
SJIA0942E
ZHA152H
RJIA4071E