Infiniti FX35, FX50 (S51). Manual - part 1165

DIAGNOSIS SYSTEM (UNIFIED METER & A/C AMP.)

HAC-57

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

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DIAGNOSIS SYSTEM (UNIFIED METER & A/C AMP.)

WITHOUT ACCS

WITHOUT ACCS : Diagnosis Description

INFOID:0000000005246243

SELF-DIAGNOSIS SYSTEM

The self-diagnosis system is built into the unified meter and A/C amp. to quickly locate the cause of malfunc-
tions.

SELF-DIAGNOSIS FUNCTION

• The self-diagnosis system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to appli-

cable sections (items) for details. Shifting from normal control to the self-diagnosis system is accomplished
by starting the engine (turning the ignition switch ON) and pressing OFF switch for at least 5 seconds. The
OFF switch must be pressed within 10 seconds after starting the engine (ignition switch is turned ON). This
system is canceled by either pressing AUTO switch or turning the ignition switch OFF. Shifting from one step
is accomplished by means of turning temperature control dial (driver side), as required.

• Shifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of pressing fan (UP: +)

switch.

- Temperature setting trimmer. Refer to 

HAC-6, "WITHOUT ACCS : Temperature Setting Trimmer"

.

- Foot position setting trimmer. Refer to 

HAC-7, "WITHOUT ACCS : Foot Position Setting Trimmer"

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HAC-58

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

DIAGNOSIS SYSTEM (UNIFIED METER & A/C AMP.)

- Inlet port memory function. Refer to 

HAC-8, "WITHOUT ACCS : Inlet Port Memory Function"

.

CONFORMATION METHOD

1.

SET IN SELF-DIAGNOSIS MODE

1.

Turn ignition switch ON.

2.

Set in self-diagnosis mode as per the following. Press OFF switch for at least 5 seconds Within 10 sec-
onds after starting engine (ignition switch is turned ON).

NOTE:
• If battery voltage drops below 12 V during diagnosis STEP-3, door motor speed becomes slower and as a

result, the system may generate an error even when operation is normal. Start engine before performing this
diagnosis to avoid this.

• Former STEP-1 (indicators and display screen are checked) does not exist in this self-diagnosis function.
• OFF switch may not be recognized according to the timing of pressing it. Operate OFF switch after the

intake switch indicators are turned ON.

>> GO TO 2.

2.

STEP-2: SENSOR AND DOOR MOTOR CIRCUITS ARE CHECKED FOR OPEN OR SHORT CIRCUIT

JMIIA0489GB

DIAGNOSIS SYSTEM (UNIFIED METER & A/C AMP.)

HAC-59

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

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Does code No. 20 appear on the display?

YES

>> GO TO 3.

NO

>> GO TO 11.

3.

STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED

Turn temperature control dial (driver side) clockwise.

Does code No. 30 appear on the display?

YES

>> GO TO 4.

NO

>> GO TO 12.

4.

STEP-4: OPERATION OF EACH DOOR MOTOR IS CHECKED

1.

Turn temperature control dial (driver side) clockwise.

2.

Press DEF (

) switch. Code No. of each door motor test is

indicated on the display.

>> GO TO 5.

5.

CHECK ACTUATORS

Refer to the following chart and check discharge air flow, air temperature, blower motor duty ratio and com-
pressor operation.

Checks must be made visually, by listening the sound, or by touching air outlets with hand, etc. for improper
operation. Refer to 

VTL-5, "System Description"

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Is this inspection result normal?

YES

>> GO TO 6.

NO-1

>> Air outlet does not change. Refer to 

HAC-70, "Diagnosis Procedure"

.

NO-2

>> Intake door does not change. Refer to 

HAC-76, "WITHOUT ACCS : Diagnosis Procedure"

.

SJIA1778E

SJIA1779E

SJIA1780E

Code  No.

41

42

43

44

45

46

Mode door position

VENT

B/L 1

B/L 2

FOOT

D/F

DEF

Intake door position

REC

REC

20% FRE

FRE

FRE

FRE

Air mix door position

FULL COOL

FULL COOL

FULL HOT

FULL HOT

FULL HOT

FULL HOT

Blower motor duty ratio

37%

91%

65%

65%

65%

91%

Compressor (Magnet 
clutch)

ON

ON

OFF

OFF

ON

ON

Electronic control valve 
(ECV) duty ratio

100%

100%

0%

0%

50%

100%

HAC-60

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

DIAGNOSIS SYSTEM (UNIFIED METER & A/C AMP.)

NO-3

>> Discharge air temperature (driver side) does not change. Refer to 

HAC-72, "Diagnosis Proce-

dure"

.

NO-4

>> Discharge air temperature (passenger side) does not change. Refer to 

HAC-74, "Diagnosis Pro-

cedure"

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NO-5

>> Blower motor operation is malfunctioning. Refer to 

HAC-80, "Diagnosis Procedure"

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NO-6

>> Magnet clutch does not engage. Refer to 

HAC-84, "Diagnosis Procedure"

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6.

STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED

1.

Turn temperature control dial (driver side) clockwise.

2.

Code No. 51 appears on the display.

>> GO TO 7.

7.

CHECK AMBIENT SENSOR

Press DEF (

) switch one time. Temperature detected by ambient

sensor is indicated on the display.
NOTE:
Check sensor circuit first if the temperature indicated on the display
greatly differs from the actual temperature, and then check sensor.

Is this inspection result normal?

YES

>> GO TO 8.

NO

>> Go to Ambient Sensor Circuit. Refer to 

HAC-88, "Diag-

nosis Procedure"

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8.

CHECK IN-VEHICLE SENSOR

Press DEF (

) switch for the second time. Temperature detected

by in-vehicle sensor is indicated on the display.
NOTE:
Check sensor circuit first if the temperature indicated on the display
greatly differs from the actual temperature, and then check sensor.

Is this inspection result normal?

YES

>> GO TO 9.

NO

>> Go to In-vehicle Sensor Circuit. Refer to 

HAC-91, "Diag-

nosis Procedure"

.

9.

CHECK INTAKE SENSOR

Press DEF (

) switch for the third time. Temperature detected by

intake sensor is indicated on the display.
NOTE:
Check sensor circuit first if the temperature indicated on the display
greatly differs from the actual temperature, and then check sensor.

Is this inspection result normal?

YES

>> GO TO 10.

NO

>> Go to Intake Sensor Circuit. Refer to 

HAC-97, "Diagno-

sis Procedure"

.

10.

CHECK CAN COMMUNICATION ERROR

PJIA0151E

PJIA0152E

PJIA0153E