2007 INFINITI M35 air intake

TROUBLE DIAGNOSIS
ATC-85
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AT C
Revision: 2007 April2007 M35/M45
Intake Door Motor CircuitNJS000GS
SYMPTOM

Intake door does not change.

Intake door motor does not operate normally.
INSPECTION FLOW
*1ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2 to 6.*2AT C - 11 2 , "
Ambient Sensor Circuit"*3ATC-115, "In-vehicle Sensor Circuit"
*4ATC-118, "Sunload Sensor Circuit"*5AT C - 8 2 , "Air Mix Door Motor Cir-
cuit"
*6ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*7ATC-71, "
LAN System Circuit"*8ATC-132, "INTAKE DOOR
MOTOR"
*9ATC-65, "Operational Check"
*10ATC-41, "SYMPTOM TABLE"*11ATC-121, "Intake Sensor Circuit"
RJIA4066E

ATC-86
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
SYSTEM DESCRIPTION
Component Parts
Intake door control system components are:

Unified meter and A/C amp.

Intake door motor (LCU)

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
The intake door control determines intake door position based on the ambient temperature, the intake air tem-
perature and the in-vehicle temperature. When shifting mode position D/F, when the DEF or OFF switches are
pressed, or when A/C switch is OFF, the unified meter and A/C amp. sets the intake door at the FRE position.
Intake Door Control Specification
RJIA4214E
RJIA4067E

TROUBLE DIAGNOSIS
ATC-87
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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

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-94
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
SYSTEM DESCRIPTION
Unified meter and A/C amp. controls compressor operation by ambient temperature, intake air temperature
and signal from ECM.
Low Temperature Protection Control
Unified meter and A/C amp. will turn compressor ON or OFF as determined by a signal detected by ambient
sensor and intake sensor.
When ambient temperature is higher than −2°C (28°F), the compres-
sor turns ON. The compressor turns OFF when ambient temperature
is lower than −5°C (23°F).
When intake air temperature is higher than 1°C (34°F), the compres-
sor turns ON. The compressor turns OFF when intake air tempera-
ture is lower than −5°C (23°F).
DIAGNOSIS PROCEDURE FOR MAGNET CLUTCH
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
RHA094GB
SJIA0267E
RJIA4078E

TROUBLE DIAGNOSIS
ATC-95
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Revision: 2007 April2007 M35/M45
1. CHECK AMBIENT SENSOR AND INTAKE SENSOR CIRCUIT
Check ambient sensor and intake sensor. Refer to AT C - 5 7 , "
FUNCTION CONFIRMATION PROCEDURE" ,
see No. 9 and 11.
OK or NG
OK >> GO TO 2.
NG >>

Malfunctioning ambient sensor: Refer to AT C - 11 2 , "Ambient Sensor Circuit" .

Malfunctioning intake sensor: Refer to ATC-121, "Intake Sensor Circuit" .
2. PERFORM AUTO ACTIVE TEST
Refer to PG-23, "
Auto Active Test" .
Does the magnet clutch operate?
YES >>
WITH CONSULT-II: GO TO 5.

WITHOUT CONSULT-II: GO TO 6.
NO >> Check 10A fuse (No. 79, located in IPDM E/R). Refer to PG-28, "
IPDM E/R Terminal Arrange-
ment" , and GO TO 3.
3. CHECK CIRCUIT CONTINUITY BETWEEN IPDM E/R AND COMPRESSOR
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector and compressor connector.
3. Check continuity between IPDM E/R harness connector E8 ter-
minal 34 and compressor harness connector F24 terminal 1.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK MAGNET CLUTCH CIRCUIT
Check for operation sound when applying battery voltage direct cur-
rent to terminal.
OK or NG
OK >> 1. Replace IPDM E/R.
2. Go to self-diagnosis procedure AT C - 5 7 , "
FUNCTION
CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-4. Confirm that magnet clutch opera-
tion normal.
NG >> 1. Replace compressor.
2. Go to self-diagnosis procedure AT C - 5 7 , "
FUNCTION
CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-4. Confirm that magnet clutch operation normal.
34 – 1 : Continuity should exist.
RJIA4079E
RJIA2005E

ATC-102
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
PERFORMANCE CHART
Test Condition
Testing must be performed as follows:
Test Reading (VQ35DE)
Recirculating-to-discharge Air Temperature Table
Ambient Air Temperature-to-operating Pressure Table
Vehicle condition Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door windows Open
Hood Open
TEMP. Max. COLD
Mode switch
(Ventilation) set
Intake switch
(Recirculation) set
Fan (blower) speedMax. speed set
Engine speed Idle speed
Operate the air conditioning system for 10 minutes before taking measurements.
Inside air (Recirculating air) at blower assembly inlet
Discharge air temperature at center ventilator
°C (°F) Relative humidity
%Air temperature
°C (°F)
50 - 6020 (68) 5.5 - 7.2 (42 - 45)
25 (77) 8.5 - 10.9 (47 - 52)
30 (86) 12.3 - 15.1 (54 - 59)
35 (95) 16.5 - 19.8 (62 - 68)
40 (104) 21.0 - 25.0 (70 - 77)
60 - 7020 (68) 7.2 - 9.0 (45 - 48)
25 (77) 10.9 - 13.4 (52 - 56)
30 (86) 15.1 - 18.0 (59 - 64)
35 (95) 19.8 - 23.0 (68 - 73)
40 (104) 25.0 - 29.0 (77 - 84)
Ambient air
High-pressure (Discharge side)
kPa (kg/cm
2 , psi)Low-pressure (Suction side)
kPa (kg/cm2 , psi) Relative humidity
%Air temperature
°C (°F)
50 - 7020 (68)733 - 895
(7.5 - 9.1, 106.3 - 129.8)180 - 220
(1.8 - 2.2, 26.1 - 31.9)
25 (77)838 - 1,025
(8.5 - 10.5, 121.5 - 148.6)210 - 257
(2.1 - 2.6, 30.5 - 37.3)
30 (86)985 - 1,204
(10.0 - 12.3, 142.8 - 174.6)239 - 293
(2.4 - 3.0, 34.7 - 42.5)
35 (95)1,115 - 1,363
(11.4 - 13.9, 161.7 - 197.6)270 - 330
(2.8 - 3.4, 39.2 - 47.9)
40 (104)1,294 - 1,581
(13.2 - 16.1, 187.6 - 229.2)331 - 405
(3.4 - 4.1, 48.0 - 58.7)

TROUBLE DIAGNOSIS
ATC-105
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Revision: 2007 April2007 M35/M45
High-pressure Side is Too Low and Low-pressure Side is Too High
Both High- and Low-pressure Sides are Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too low and
low-pressure side is too high.High- and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.Replace compressor.
No temperature difference
between high- and low-pres-
sure sides.Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.Replace compressor.
AC356A
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too low.

There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.

Liquid tank inlet and expan-
sion valve are frosted.Liquid tank inside is slightly
clogged.

Replace liquid tank.

Check lubricant for contami-
nation.

Temperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.

Expansion valve inlet is
frosted.

Temperature difference
occurs somewhere in high-
pressure side.High-pressure pipe located
between liquid tank and
expansion valve is clogged.

Check and repair malfunc-
tioning parts.

Check lubricant for contami-
nation.
Expansion valve and liquid
tank are warm or slightly cool
when touched.Low refrigerant charge.
↓
Leaking fittings or compo-
nents.Check refrigerant for leaks.
Refer to ATC-169, "
Checking
for Refrigerant Leaks" .
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted.Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion valve
adjustment.
2. Malfunctioning expansion
valve.
3. Outlet and inlet may be
clogged.

Remove foreign particles by
using compressed air.

Replace expansion valve.

Check lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.Low-pressure pipe is clogged
or crushed.

Check and repair malfunc-
tioning parts.

Check lubricant for contami-
nation.
Air flow volume is not enough
or is too low.Evaporator is frozen.

Check intake sensor circuit.
Refer to ATC-121, "
Intake
Sensor Circuit" .

Replace compressor.

Repair evaporator fins.

Replace evaporator.

Refer to AT C - 8 8 , "Blower
Motor Circuit" .
AC353A