Nissan Murano Z50 (2006 year). Manual - part 7

 

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Nissan Murano Z50 (2006 year). Manual - part 7

 

 

TROUBLE DIAGNOSIS

ATC-73

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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, intake door motor and air mix 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.

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).

SJIA0526E

ATC-74

TROUBLE DIAGNOSIS

Revision: 2006 August

2006 Murano

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. 

RJIA1996E

ZHA152H

SJIA0266E

TROUBLE DIAGNOSIS

ATC-75

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1. 

CHECK POWER SUPPLY FOR BLOWER MOTOR

1.

Disconnect blower motor connector.

2.

Turn ignition switch ON.

3.

Check voltage between blower motor harness connector M70
terminal 1 and ground.

OK or NG

OK

>> GO TO 2.

NG

>> Check power supply circuit and 15A fuses [Nos. 10 and 

11, located in the fuse block (J/B)]. Refer to 

PG-69, 

"FUSE BLOCK - JUNCTION BOX (J/B)"

 .

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

If fuse are NG, check harness for short circuit and replace fuse.

2. 

CHECK BLOWER MOTOR GROUND CIRCUIT

1.

Turn ignition switch OFF.

2.

Check continuity between blower motor harness connector M70
terminal 3 and ground.

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connector.

3. 

CHECK CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND UNIFIED METER AND A/C AMP.

1.

Disconnect unified meter and A/C amp. connector.

2.

Check continuity between blower motor harness connector M70
terminal 2 and unified meter and A/C amp. harness connector
M51 terminal 53.

OK or NG

OK

>> GO TO 4.

NG

>> Repair harness or connector.

4. 

CHECK UNIFIED METER AND A/C AMP. OUTPUT SIGNAL

1.

Reconnect blower motor connector and unified meter and A/C
amp. connector.

2.

Turn ignition switch ON.

3.

Change the fan speed from Lo to Hi, and check the duty ratios
between the blower motor harness connector M70 terminal 2

1 – Ground

: Battery voltage

RJIA1997E

3 – Ground

: Continuity should exist.

RJIA1998E

2 – 53

: Continuity should exist.

RJIA1999E

RJIA2000E

ATC-76

TROUBLE DIAGNOSIS

Revision: 2006 August

2006 Murano

and ground by using an oscilloscope. Normal terminal 2 drive signal duty ratios are shown in the table
below.

OK or NG

OK

>> Replace blower motor after confirming the fan air flow does not change.

NG

>> Replace unified meter and A/C amp.

COMPONENT INSPECTION
Blower Motor

Confirm smooth rotation of the blower motor.

Ensure that there are no foreign particles inside the blower unit.

RJIA1792E

RJIA1793E

TROUBLE DIAGNOSIS

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Magnet Clutch Circuit

NJS000B5

SYMPTOM: Magnet clutch does not engage.

INSPECTION FLOW

*1

ATC-104, "Intake Sensor Circuit"

*2

ATC-95, "Ambient Sensor Circuit"

*3

ATC-48, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 13.

*4

ATC-78, "DIAGNOSIS PROCEDURE 
FOR MAGNET CLUTCH"

*5

ATC-88, "TROUBLE DIAGNOSIS 
FOR UNUSUAL PRESSURE"

*6

ATC-55, "Operational Check"

*7

ATC-48, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 4 to 6.

*8

ATC-36, "SYMPTOM TABLE"

SJIA1162E

ATC-78

TROUBLE DIAGNOSIS

Revision: 2006 August

2006 Murano

SYSTEM DESCRIPTION

Unified meter and A/C amp. controls compressor operation by ambient temperature and signal from ECM.

Low Temperature Protection Control

Unified meter and A/C amp. will turn the compressor ON or OFF as determined by a signal detected by intake
sensor.
When intake air temperature is higher than 4

°

C (39

°

F), the compres-

sor turns ON. The compressor turns OFF when intake air tempera-
ture is lower than 2.5

°

C (37

°

F).

DIAGNOSIS PROCEDURE FOR MAGNET CLUTCH

SYMPTOM: Magnet clutch does not engage when A/C switch is ON.

1. 

CHECK INTAKE SENSOR CIRCUIT

Check intake sensor. Refer to 

ATC-48, "FUNCTION CONFIRMATION PROCEDURE"

 , see No. 11.

OK or NG

OK

>> GO TO 2.

NG

>> Malfunctioning intake sensor: Refer to 

ATC-104, "Intake Sensor Circuit"

 .

2. 

PERFORM AUTO ACTIVE TEST

Refer to 

PG-21, "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-25, "IPDM E/R Terminal Arrange-

ment"

  and GO TO 3.

RHA094GD

SJIA1232E

TROUBLE DIAGNOSIS

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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 33 and compressor harness connector F28 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 

ATC-48, "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 

ATC-48, "FUNCTION

CONFIRMATION PROCEDURE"

  and perform self-

diagnosis STEP-4. Confirm that magnet clutch operation normal.

5. 

CHECK BCM INPUT (COMPRESSOR ON) SIGNAL

Check compressor ON/OFF signal. Refer to 

ATC-35, "CONSULT-II

Function (BCM)"

 .

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 6.

6. 

CHECK CIRCUIT CONTINUITY BETWEEN BCM AND UNIFIED METER AND A/C AMP.

1.

Turn ignition switch OFF.

2.

Disconnect BCM connector and unified meter and A/C amp.
connector.

3.

Check continuity between BCM harness connector M34 terminal
27 and unified meter and A/C amp. harness connector M51 ter-
minal 42.

OK or NG

OK

>> GO TO 7.

NG

>> Repair harness or connector.

33 – 1

: Continuity should exist.

RJIA2004E

RJIA2005E

A/C SW ON

: AIR COND SW ON

A/C SW OFF

: AIR COND SW OFF

RJIA1111E

27 – 42

: Continuity should exist.

RJIA2006E

ATC-80

TROUBLE DIAGNOSIS

Revision: 2006 August

2006 Murano

7. 

CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (COMPRESSOR ON SIGNAL)

1.

Reconnect BCM connector and unified meter and A/C amp.
connector.

2.

Turn ignition switch ON.

3.

Check voltage between unified meter and A/C amp. harness
connector M51 terminal 42 and ground.

OK or NG

OK

>> GO TO 8.

NG-1

>> If the voltage is approx. 5 V when A/C switch is ON: Replace unified meter and A/C amp.

NG-2

>> If the voltage is approx. 0 V when A/C switch is OFF: Replace BCM.

8. 

CHECK REFRIGERANT PRESSURE SENSOR

WITH CONSULT-II

1.

Start the engine.

2.

Check voltage of refrigerant pressure sensor. Refer to 

EC-127, "CONSULT-II Reference Value in Data

Monitor"

 .

WITHOUT CONSULT-II

1.

Start the engine.

2.

Check voltage between ECM harness connector F101 terminal
70 and ground.

OK or NG

OK

>>

WITH CONSULT-II: GO TO 9.

WITHOUT CONSULT-II: GO TO 10.

NG

>> Refer to 

EC-653, "REFRIGERANT PRESSURE SENSOR"

 .

Terminals

Condition

Voltage

(+)

(

)

Unified meter and 

A/C amp. connector

Terminal No.

M51

42

Ground

A/C switch: ON 
(Blower motor 
operates.)

Approx. 0 V

OFF switch: ON 
(A/C system: 
OFF)

Approx. 5 V

RJIA2007E

Terminals

Condition

Voltage

(+)

(

)

ECM 

connector

Terminal No.

F101

70

Ground

A/C switch: ON 
(Blower motor 
operates.)

Approx. 1.0 - 4.0 V

PBIB1188E

TROUBLE DIAGNOSIS

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9. 

CHECK BCM INPUT (FAN ON) SIGNAL

Check FAN ON/OFF signal. Refer to 

ATC-35, "CONSULT-II Function

(BCM)"

 .

OK or NG

OK

>> GO TO 12.

NG

>> GO TO 10.

10. 

CHECK CIRCUIT CONTINUITY BETWEEN BCM AND UNIFIED METER AND A/C AMP.

1.

Turn ignition switch OFF.

2.

Disconnect BCM connector and unified meter and A/C amp.
connector.

3.

Check continuity between BCM harness connector M34 terminal
28 and unified meter and A/C amp. harness connector M51 ter-
minal 57.

OK or NG

OK

>> GO TO 11.

NG

>> Repair harness or connector.

11. 

CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (FAN ON SIGNAL)

1.

Reconnect BCM connector and unified meter and A/C amp.
connector.

2.

Turn ignition switch ON.

3.

Check voltage between unified meter and A/C amp. harness
connector M51 terminal 57 and ground.

OK or NG

OK

>> GO TO 12.

NG-1

>> If the voltage is approx. 5 V when blower motor is ON: Replace unified meter and A/C amp.

NG-2

>> If the voltage is approx. 0 V when blower motor is OFF: Replace BCM.

FAN CONTROL DIAL ON

: FAN ON SIG ON

FAN CONTROL DIAL OFF

: FAN ON SIG OFF

RJIA1111E

28 – 57

: Continuity should exist.

RJIA2009E

Terminals

Condition

Voltage

(+)

(

)

Unified meter 

and A/C amp. 

connector

Terminal 

No.

M51

57

Ground

Fan control dial: ON
(Blower motor oper-
ates.)

Approx. 0 V

Fan control dial: OFF

Approx. 5 V

RJIA2010E

ATC-82

TROUBLE DIAGNOSIS

Revision: 2006 August

2006 Murano

12. 

CHECK CAN COMMUNICATION

Check CAN communication. Refer to 

BCS-13, "CAN Communication Inspection Using CONSULT-II (Self-

Diagnosis)"

 .

BCM – ECM

ECM – IPDM E/R

ECM – Unified meter and A/C amp.

OK or NG

OK

>> Replace ECM.

NG

>> Repair or replace malfunctioning part(s).

COMPONENT INSPECTION
Refrigerant Pressure Sensor

The refrigerant pressure sensor is attached to the condenser.
Make sure that the A/C refrigerant pressure and the sensor output
voltage are within the specified range as shown in the A/C operating
condition figure. Refer to 

EC-653, "REFRIGERANT PRESSURE

SENSOR"

 .

RJIA1795E

SJIA1841E

TROUBLE DIAGNOSIS

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Revision: 2006 August

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Insufficient Cooling

NJS000B6

SYMPTOM: Insufficient cooling

INSPECTION FLOW

SJIA1230E

TROUBLE DIAGNOSIS

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PERFORMANCE TEST DIAGNOSIS

*1

ATC-87, "PERFORMANCE CHART"

*2

ATC-87, "PERFORMANCE CHART"

*3

ATC-88, "TROUBLE DIAGNOSIS 
FOR UNUSUAL PRESSURE"

*4

ATC-66, "Air Mix Door Motor Circuit"

SJIA1226E

ATC-86

TROUBLE DIAGNOSIS

Revision: 2006 August

2006 Murano

*1

ATC-135, "Check Disc to Pulley 
Clearance"

*2

ATC-72, "Blower Motor Circuit"

*3

EM-13, "Checking Drive Belts"

SJIA1642E

TROUBLE DIAGNOSIS

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PERFORMANCE CHART
Test Condition

Testing must be performed as follows:

Test Reading

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

Recirculation (REC) switch

 (Recirculation) set

 Fan (blower) speed

Max. 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 - 60

20 (68)

5.3 - 6.5 (42 - 44)

25 (77)

9.7 - 11.5 (49 - 53)

30 (86)

13.8 - 16.3 (57 - 61)

35 (95)

18.0 - 21.2 (64 - 70)

40 (104)

22.2 - 25.7 (72 - 78)

60 - 70

20 (68)

6.5 - 7.7 (44 - 46)

25 (77)

11.5 - 13.3 (53 - 56)

30 (86)

16.3 - 18.8 (61 - 66)

35 (95)

21.2 - 24.0 (70 - 75)

40 (104)

25.7 - 29.2 (78 - 85)

Ambient air

High-pressure (Discharge side)

kPa (kg/cm

2

 , psi)

Low-pressure (Suction side)

kPa (kg/cm

2

 , psi)

Relative humidity

%

Air temperature

°

C (

°

F)

50 - 70

20 (68)

680 - 840

(6.94 - 8.57, 98.6 - 121.8)

160 - 198

(1.63 - 2.02, 23.2 - 28.7)

25 (77)

800 - 985

(8.16 - 10.05, 116.0 - 142.8)

198 - 245

(2.02 - 2.50, 28.7 - 35.5)

30 (86)

940 - 1,150

(9.59 - 11.73, 136.3 - 166.8)

225 - 278

(2.30 - 2.84, 32.6 - 40.3)

35 (95)

1,160 - 1,410

(11.83 - 14.38, 168.2 - 204.5)

273 - 335

(2.78 - 3.42, 39.6 - 48.6)

40 (104)

1,325 - 1,620

(13.52 - 16.52, 192.1 - 234.9)

325 - 398

(3.32 - 4.06, 47.1 - 57.7)

ATC-88

TROUBLE DIAGNOSIS

Revision: 2006 August

2006 Murano

TROUBLE DIAGNOSIS FOR UNUSUAL PRESSURE

Whenever system’s high and/or low side pressure(s) is/are unusual, diagnose using a manifold gauge. The
marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the
standard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air tempera-
ture-to-operating pressure table).

Both High- and Low-pressure Sides are Too High

High-pressure Side is Too High and Low-pressure Side is Too Low

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Both high- and low-pressure sides 
are too high.

The pressure return to normal 
soon after water is splashed 
on condenser.

Excessive refrigerant charge 
in refrigeration cycle.

Reduce refrigerant until speci-
fied pressure is obtained.

Air suction by cooling fan is 
insufficient.

Insufficient condenser cooling 
performance.

1. Condenser fins are clogged.

2. Improper fan rotation of 

cooling fan.

Clean condenser.

Check and repair cooling fan 
as necessary.

Low-pressure pipe is not 
cold.

When compressor is 
stopped high-pressure 
value quickly drops by 
approximately 196 kPa (2 
kg/cm

2

 , 28 psi). It then 

decreases gradually there-
after.

Poor heat exchange in con-
denser
(After compressor operation 
stops, high-pressure 
decreases too slowly.).

Air in refrigeration cycle.

Evacuate repeatedly and 
recharge system.

Engine tends to overheat.

Engine cooling systems mal-
function.

Check and repair each engine 
cooling system.

An area of the low-pres-
sure pipe is colder than 
areas near the evaporator 
outlet.

Low-pressure pipe is 
sometimes covered with 
frost.

Excessive liquid refrigerant 
on low-pressure side.

Excessive refrigerant dis-
charge flow.

Expansion valve is open a 
little compared with the 
specification.

 

Improper expansion valve 
adjustment.

Replace expansion valve.

AC359A

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

High-pressure side is too high and 
low-pressure side is too low.

Upper side of condenser and 
high-pressure side are hot, 
however, liquid tank is not so 
hot.

High-pressure tube or parts 
located between compressor 
and condenser are clogged or 
crushed.

Check and repair or replace 
malfunctioning parts.

Check lubricant for contami-
nation.

AC360A

 

 

 

 

 

 

 

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