Nissan Sentra. Manual - part 544

HAC-24

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

DIAGNOSIS SYSTEM (A/C AUTO AMP.)

DIAGNOSIS SYSTEM (A/C AUTO AMP.)

Description

INFOID:0000000009757629

Air conditioning system performs self-diagnosis, operation check, function diagnosis, and various settings

using diagnosis function of each control unit.

CONSULT Function (HVAC)

INFOID:0000000009757630

CONSULT can display each diagnosis item using the diagnosis test modes as shown. 

CONSULT application items

SELF-DIAGNOSTIC RESULT

Refer to 

HAC-38, "DTC Index"

.

Display Item List

ECU

Diagnostic item

(CONSULT)

A/C auto amp.

HVAC

Self Diagnostic Result

Data Monitor

Active Test

Work support

BCM

BCM-AIR CONDITIONER

Self Diagnostic Result

Data Monitor

ECM

ENGINE

Self Diagnostic Result

Data Monitor

IPDM E/R

IPDM E/R

Self Diagnostic Result

Data Monitor

Auto active test

Diagnosis mode

Description

Self-Diagnostic Result

Displays the diagnosis results judged by A/C auto amp.

Data Monitor

Displays A/C auto amp. input/output data in real time.

Work support

Changes the setting for each system function.

Active Test

The signals used to activate each device are forcibly supplied from A/C auto amp.

ECU Identification

Displays the A/C auto amp. number.

DTC

Items

 (CONSULT screen terms)

Diagnostic item is detected when...

Possible cause

U1000

CAN COMM CIRCUIT

When A/C auto amp. is not transmitting 
or receiving CAN communication signal 
for 2 or more seconds.

CAN communication system

U1010

CONTROL UNIT (CAN)

When detecting error during the initial 
diagnosis of CAN controller of A/C auto 
amp.

A/C auto amp.

B257B

AMB TEMP SEN (SHORT)

Detected temperature at ambient sen-
sor 55

°C (131°F) or more

• Ambient sensor
• A/C auto amp.
• Harness and connector

(Ambient sensor circuit is open, 
or there is a short in the circuit)

B257C

AMB TEMP SEN (OPEN)

Detected temperature at ambient sen-
sor 

−30°C (−22°F) or less

B2578

IN-CAR SENSOR (OUT OF RANGE 
[LOW])

Detected temperature at in-vehicle sen-
sor 55

°C (131°F) or more

• In-vehicle sensor
• A/C auto amp.
• Harness and connector

(In-vehicle sensor circuit is open, 
or there is a short in the circuit)

B2579

IN-CAR SENSOR (OUT OF RANGE 
[HI])

Detected temperature at in-vehicle sen-
sor 

−30°C (−22°F) or less

DIAGNOSIS SYSTEM (A/C AUTO AMP.)

HAC-25

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

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HAC

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*: Perform self-diagnosis under sunshine. When performing indoors, aim a light (more than 60 W) at sunload sensor, otherwise self-diag-
nosis reports an error even though the sunload sensor is functioning normally.

DATA MONITOR

Display item list

B2581

EVAP TEMP SEN (SHORT)

Detected temperature at intake sensor 
55

°C (131°F) or more

• Intake sensor
• A/C auto amp.
• Harness and connector

(Intake sensor circuit is open, or 
there is a short in the circuit)

B2582

EVAP TEMP SEN (OPEN)

Detected temperature at intake sensor 
−30°C (−22°F) or less

B2630

*

SUNLOAD SEN (SHORT)

Detected calorie at sunload sensor 
1395 w/m

2

 (1200 kcal/m

2

·h) 

• Sunload sensor
• A/C auto amp.
• Harness and connector

(Sunload sensor circuit is open, 
or there is a short in the circuit)

B2631

*

SUNLOAD SEN (OPEN)

Detected calorie at sunload sensor 0 w/
m

2

 (0 kcal/m

2

·h) 

B27A2

DR AIRMIX ACTR

Short or open circuit of air mix door mo-
tor drive signal terminal 1.

• Air mix door motor LH
• A/C auto amp.
• Harness and connector

(Air mix door motor is open or 
shorted)

B27A3

Short or open circuit of air mix door mo-
tor drive signal terminal 2.

B27A4

Short or open circuit of air mix door mo-
tor drive signal terminal 3.

B27A5

Short or open circuit of air mix door mo-
tor drive signal terminal 4.

B27AA

AS AIRMIX ACTR

Short or open circuit of air mix door mo-
tor drive signal terminal 1.

• Air mix door motor RH
• A/C auto amp.
• Harness and connector

(Air mix door motor is open or 
shorted)

B27AB

Short or open circuit of air mix door mo-
tor drive signal terminal 2.

B27AC

Short or open circuit of air mix door mo-
tor drive signal terminal 3.

B27AD

Short or open circuit of air mix door mo-
tor drive signal terminal 4.

B27A0

INTAKE ACTR

PBR opening angle of intake door mo-
tor is 50% or more. (PBR feedback sig-
nal voltage of intake door motor is 2.5V 
or more)

• Intake door motor
• A/C auto amp.
• Harness and connector

(Intake door motor is open or 
shorted)

B27A1

PBR opening angle of intake door mo-
tor is 30% or less. (PBR feedback sig-
nal voltage of intake door motor is 1.5V 
or less)

B27A6

MODE DOOR ACTR

Short or open circuit of air mix door mo-
tor drive signal terminal 1.

• Mode door motor
• A/C auto amp.
• Harness and connector

(Mode door motor is open or 
shorted)

B27A7

Short or open circuit of air mix door mo-
tor drive signal terminal 2.

B27A8

Short or open circuit of air mix door mo-
tor drive signal terminal 3.

B27A9

Short or open circuit of air mix door mo-
tor drive signal terminal 4.

DTC

Items

 (CONSULT screen terms)

Diagnostic item is detected when...

Possible cause

Monitor item [Unit]

Description

AMB TEMP SEN

[

°C]

Ambient sensor value converted from ambient sensor signal received from ambient 
sensor 

IN-VEH TEMP

[

°]

In-vehicle sensor value converted from in-vehicle sensor signal received from in-vehi-
cle sensor 

INT TEMP SEN

[

°C] Intake sensor value converted from intake sensor signal received from intake sensor 

HAC-26

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

DIAGNOSIS SYSTEM (A/C AUTO AMP.)

WORK SUPPORT

NOTE:
When the battery cable is disconnected from the negative terminal or when the battery voltage becomes 10V or less, the setting of
WORK SUPPORT may be cancelled. 

ACTIVE TEST

HVAC TEST

SUNLOAD SEN

[w/m

2

]

Sunload sensor value converted from sunload sensor signal received from sunload 
sensor 

AMB SEN CAL

[

°] Ambient sensor value calculated by A/C auto amp.

IN-VEH CAL

[

°C] In-vehicle sensor value calculated by A/C auto amp.

INT TEMP CAL

[

°C] Intake sensor value calculated by A/C auto amp.

SUNL SEN CAL

[w/m

2

] Sunload sensor value calculated by A/C auto amp.

COMP REQ SIG

[On/Off] Displays A/C switch ON/OFF status transmitted to other units via CAN communication

FAN REQ SIG

[On/Off]

Displays blower switch ON/OFF status transmitted to other units via CAN communica-
tion

FAN DUTY

[%] Duty ratio of blower motor judged by A/C auto amp.

XM

Target discharge air temperature judged by A/C auto amp. according to the tempera-
ture setting and the value from each sensor

ENG COOL TEMP

[

°C] Water temperature signal value received from ECM via CAN communication

VEHICLE SPEED

[km/h

(mph)]

Vehicle speed signal value received from meter via CAN communication

Monitor item [Unit]

Description

Work item

Description

Reference

TEMP SET CORRECT
(Setting of difference between tem-
perature setting and control tempera-
ture)

If the temperature felt by the customer is different than the airflow 
temperature controlled by the temperature setting, the auto ampli-
fier control temperature can be adjusted to compensate for the 
temperature setting. 

HAC-55, "Temperature 
Setting Trimmer"

REC MEMORY SET
(REC memory function setting)

• If the ignition switch is turned to the OFF position while the REC 

switch is set to ON (recirculation), “With” or “Without” of the REC 
switch ON (recirculation) condition can be selected. 

• If “With” was set, the REC switch will be ON (recirculation) when 

turning the ignition switch to the ON position again. 

• If “Without” was set, the air inlets will be controlled automatically 

when turning the ignition switch to the ON position again. 

HAC-56, "Inlet Port 
Memory Function (REC)"

FRE MEMORY SET
(FRE memory function setting)

• If the ignition switch is turned to the OFF position while the FRE 

switch is set to ON (fresh air intake), “With” or “Without” of the 
FRE switch ON (fresh air intake) condition can be selected. 

• If “With” was set, the FRE switch will be ON (fresh air intake) 

when turning the ignition switch to the ON position again. 

• If “Without” was set, the air inlets will be controlled automatically 

when turning the ignition switch to the ON position again. 

HAC-55, "Inlet Port 
Memory Function (FRE)"

Door Motor Starting Position Reset

Starting position reset of air mix door motor and mode door motor 
can be performed. 

HAC-57, "Work Proce-
dure"

TARGET EVAPORATOR TEMP UP-
PER LIMIT SETTING

Set the target evaporator upper temperature limit. 

HAC-56, "Target Evapo-
rator Temp Upper Limit"

Test item

Description

ALL SEG

All switch indicator and display indication are turned ON.

HVAC TEST

The operation check of A/C system can be performed by selecting the mode. Refer to the fol-
lowing table for the conditions of each mode.

DIAGNOSIS SYSTEM (A/C AUTO AMP.)

HAC-27

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

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D

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HAC

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NOTE:
Perform the inspection of each output device after starting the engine, because the A/C compressor has been operating. 

Test item

MODE 1

MODE 2

MODE 3

MODE 4

MODE 5

MODE 6

MODE 7

Mode door position

VENT

VENT

B/L

B/L

D/F1

D/F2

DEF

Intake door position

REC

REC

REC

20%FRE

FRE

FRE

FRE

Air mix door position 
(driver & passenger 
side)

FULL COLD

FULL COLD

FULL COLD

50%

50%

FULL HOT

FULL HOT

Blower motor (Applied 
voltage)

30%

30%

60%

HI

HI

60%

HI

A/C compressor (Mag-
net clutch)

ON

ON

ON

ON

OFF

OFF

ON

ECV duty

80%

80%

40%

40%

0%

0%

90%

Blower fan ON signal

ON

ON

ON

ON

OFF

OFF

ON