Unified NISSAN TEANA 2003 User Guide

AIR CONDITIONER CONTROL
ATC-27
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MAGNET CLUTCH CONTROL
When A/C switch is pressed (with FAN ON), press DEF switch, unified meter and A/C amp. transmits com-
pressor ON signal to BCM.
BCM sends compressor ON signal to ECM, via CAN communication.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sen-
sor signal, throttle angle, etc.). If it judges compressor can be turned ON, it sends compressor ON signal to
IPDM E/R, via CAN communication.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
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.
SJIA1648E

ATC-28
AIR CONDITIONER CONTROL

Description of Control SystemBJS000FL
The control system consists of input sensors, switches, the unified meter and A/C amp. (microcomputer) and
outputs. The relationship of these components is shown in the figure below:
SJIA1649E

ATC-30
AIR CONDITIONER CONTROL


When fan control switch (DOWN) is pressed for approximately 2 seconds or longer or press fan control
switch when blower fan motor operates at 1st speed, A/C system will turn OFF (The compressor and
blower are OFF, the intake doors and the mode doors are automatically controlled).
INTAKE SWITCH

When intake switch is ON, FRE LED turns ON, and air inlet is fixed to FRE.

When press intake switch again, REC LED turns ON, and air inlet is fixed to REC.

When intake switch is pressed for approximately 1.5 seconds or longer, FRE and REC LEDs blink twice.
Then, automatic control mode is entered. Inlet status is displayed by LED even during automatic con-
trolled.

When FRE LED is turned ON, shifting mode position to D/F or DEF, or when compressor is turned from
ON to OFF, intake switch is automatically turned OFF (fixed to FRE mode). REC mode can be re-entered
by pressing intake switch again, and then compressor is turned ON. (Except D/F or DEF position)
MODE SWITCH
The air discharge outlets is controlled with this switch.
DEFROSTER (DEF) SWITCH
Mode doors are set to the defrost position with this switch. Also, intake doors are set to the outside air position,
and compressor turns ON.
REAR WINDOW DEFOGGER SWITCH
When illumination is ON, rear window is defogged.
DUAL SWITCH

When the DUAL switch indicator is illuminated, the driver-side and passenger-side temperature can each
be set independently.

When the DUAL switch indicator is not illuminated, the driver-side setting temperature is applied to both
sides.
Fail-safe FunctionBJS000FN
If a communication error exists between the unified meter and A/C amp. and the A/C and AV switch for 30 sec-
onds or longer, air conditioner is controlled under the following conditions:
Compressor : ON
Air outlet : AUTO
Air inlet : FRE (Fresh)
Blower fan speed : AUTO
Set temperature : Setting before communication error occurs
Display : OFF

ATC-44
TROUBLE DIAGNOSIS

Auto Amp. Terminals and Reference ValueBJS000FW
Measure voltage between each terminal and ground by referring ter-
minals and reference value for unified meter and A/C amp.
PIN CONNECTOR TERMINAL LAYOUT
TERMINALS AND REFERENCE VALUE FOR UNIFIED METER AND A/C AMP.
RJIA2732E
RJIA2734E
Te r m i n a l
No.Wire
colorItemIgnition
switchConditionVoltag e
(V)
1 L CAN-H — — —
11 P C A N - L — — —
21 Y/R Power supply from BATT OFF — Battery voltage
22 G Power supply from IGN ON — Battery voltage
29 B Ground (Power) ON — Approx. 0
30 B Ground ON — Approx. 0
35 V Power supply from ACC ACC — Battery voltage
39 O/B Ambient sensor — — —
40 LG In-vehicle sensor — — —
41 R/W Intake sensor — — —
42 SB Compressor ON signal ONA/C switch: ON (Blower motor
operates.)Approx. 0
OFF switch: ON (A/C System:
OFF)
43 L/R A/C LAN signal ON —
SJIA1423J
SJIA1453J

TROUBLE DIAGNOSIS
ATC-47
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FUNCTION CONFIRMATION PROCEDURE
1. SET IN SELF-DIAGNOSIS MODE
1. Turn ignition switch ON.
2. Set in self-diagnosis mode as follows. Within 10 seconds after starting engine (ignition switch is turned
ON.), press A/C switch for at least 5 seconds.
CAUTION:

Press A/C switch after indicating LED of intake switch.

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. To avoid this,
start engine before performing this diagnosis.

Former STEP-1 (LEDs and display screen are checked) does not exist in this self-diagnosis func-
tion.
>> GO TO 2.
2. STEP-2: SENSOR CIRCUITS ARE CHECKED FOR OPEN OR SHORT CIRCUIT
Does code No. 20 appear on the display?
YES >> GO TO 3.
NO >> GO TO 13.
3. CHECK TO ADVANCE SELF-DIAGNOSIS STEP-3
Press temperature control switch (UP, driver side).
Advance to self
-diagnosis STEP-3?
YES >> GO TO 4.
NO >> Replace A/C and AV switch. (Temperature control switch is malfunctioning.)
4. CHECK TO RETURN SELF-DIAGNOSIS STEP-2
Press temperature control switch (DOWN, driver side).
Return to self
-diagnosis STEP-2?
YES >> GO TO 5.
NO >> Malfunctioning A/C and AV switch or unified meter and A/C amp. Refer to AT C - 9 4 , "
Self-diagno-
sis" .
5. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED
Press temperature control switch (UP, driver side).
Does code No. 30 appear on the display?
YES >> GO TO 6.
NO >> GO TO 14.
RHA970DB
RHA869DD

ATC-50
TROUBLE DIAGNOSIS

12. CHECK CAN COMMUNICATION ERROR
1. Press intake switch.
2. CAN communication error between the unified meter and A/C
amp. and the display unit or display control unit can be detected
as self-diagnosis results. (If plural errors occur, the display of
each error will blink twice for 0-5 second intervals.) .
OK or NG
OK >> 1. Turn ignition switch OFF or AUTO switch ON.
2. INSPECTION END
NG >> Go to CAN communication. Refer to LAN-49, "
CAN Sys-
tem Specification Chart" .

Unified meter and A/C amp. - Display unit or Display
control unit.
13. CHECK MALFUNCTIONING SENSOR
Refer to the following chart for malfunctioning code No.
(If two or more sensors malfunction, corresponding code Nos. blink respectively twice.)
*1: Perform self-diagnosis STEP-2 under sunshine.
When performing indoors, aim a light (more than 60 W) at sunload sensor, otherwise code No. 25 will indicate
despite that sunload sensor is functioning properly.
*2: AT C - 9 6 , "
DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR" .
*3: ATC-100, "
DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR" .
*4: ATC-105, "
DIAGNOSIS PROCEDURE FOR INTAKE SENSOR" .
*5: ATC-102, "
DIAGNOSIS PROCEDURE FOR SUNLOAD SENSOR" .
*6: AT C - 6 8 , "
DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR PBR" .
>> INSPECTION END
RJIA1762E
Code No. Malfunctioning sensor (Including circuits) Reference page
21 / −21 Ambient sensor *2
22 / −22 In-vehicle sensor *3
24 / −24 Intake sensor *4
25 / −25
Sunload sensor
*1*5
26 / −26 Air mix door motor PBR (Driver side)
*6
27 / −27 Air mix door motor PBR (Passenger side)
PJIA0022E

TROUBLE DIAGNOSIS
ATC-57
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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, intake
door motor, blower motor and compressor are then controlled.
When the various switches and temperature contorol switch are
operated, data is input to the unified meter and A/C amp. from the
display unit / display 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 A/C and AV switch. It can be set at an inter-
val of 0.5°C in the 18°C to 32°C temperature range by turning tem-
perature control switch. The set temperature is displayed.
DIAGNOSIS PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not come on.
RJIA2732E
RJIA3253E
SJIA0301E

ATC-58
TROUBLE DIAGNOSIS

1. CHECK POWER SUPPLY CIRCUIT FOR UNIFIED METER AND A/C AMP.
1. Disconnect unified meter and A/C amp. connector.
2. Check voltage between unified meter and A/C amp. harness
connector M42 terminals 21, 22 and 35, unified meter and A/C
amp. harness connector M45 terminal 46 and ground.
OK or NG
OK >> GO TO 2.
NG >> Check 10A and 15A fuses [Nos. 6, 10, 11, 12 and 19, located in the fuse block (J/B)]. Refer to PG-
79, "FUSE BLOCK - JUNCTION BOX (J/B)" .

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

If fuses are NG, harness for short circuit and replace fuse.
2. CHECK GROUND CIRCUIT FOR UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Check continuity between unified meter and A/C amp. harness
connector M42 terminal 29, 30 and ground.
OK or NG
OK >> Replace unified meter and A/C amp.
NG >> Repair harness or connector.
Terminals Ignition switch position
(+)
(-) OFF ACC ON Unified
meter and
A/C amp.
connectorTerminal No.
M42 21
GroundBattery volt-
ageBattery volt-
ageBattery
voltage
M42 22 Approx. 0 V Approx. 0 VBattery
voltage
M42 35 Approx. 0 VBattery volt-
ageBattery
voltage
M45 46 Approx. 0 V Approx. 0 VBattery
voltage
RJIA1984E
29, 30 – Ground : Continuity should exist.
RJIA1985E

TROUBLE DIAGNOSIS
ATC-59
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LAN System CircuitBJS000G0
SYMPTOM: Mode door motor, intake door motor and/or air mix door motor(s) does not operate normally.
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT
1. CHECK POWER SUPPLY FOR UNIFIED METER AND A/C AMP.
1. Turn ignition switch ON.
2. Check voltage between unified meter and A/C amp. harness
connector M45 terminal 54 and ground.
OK or NG
OK >> GO TO 2.
NG >> Replace unified meter and A/C amp.
2. CHECK SIGNAL FOR UNIFIED METER AND A/C AMP.
Confirm A/C LAN signal between unified meter and A/C amp. har-
ness connector M45 terminal 43 and ground using an oscilloscope.
OK or NG
OK >> GO TO 3.
NG >> Replace unified meter and A/C amp.
RJIA1775E
54 – Ground : Battery voltage
RJIA1986E
Terminals
Voltag e (+)
(-) Unified meter
and A/C amp.
connectorTe r m i n a l N o .
M45 43 Ground
RJIA1987E
SJIA1453J

TROUBLE DIAGNOSIS
ATC-61
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6. CHECK MOTOR OPERATION
1. Reconnect each door motor connector.
2. Turn ignition switch ON.
3. Confirm operation of each door motor.
OK or NG
OK >> (Return to operate normally.)

Poor contact in motor connector.
NG >> (Does not operate normally.)

GO TO 7.
7. CHECK AIR MIX DOOR MOTOR AND INTAKE DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect mode, air mix (driver side, passenger side), and intake door motor connectors.
3. Reconnect air mix (driver side, passenger side) and intake door motor connectors.
4. Turn ignition switch ON.
5. Confirm operation of air mix door motor (driver side, passenger side) and intake door motor.
OK or NG
OK >> [Air mix (driver side, passenger side) and intake door motors operate normally.]

Replace mode door motor.
NG >> [Air mix (driver side, passenger side) and intake door motors does not operate normally.]

GO TO 8.
8. CHECK MODE DOOR MOTOR AND INTAKE DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (driver side, passenger side) connectors.
3. Reconnect mode door motor connector.
4. Turn ignition switch ON.
5. Confirm operation of mode door motor and intake door motor.
OK or NG
OK >> (Mode and intake door motors operate normally.)

GO TO 10.
NG >> (Mode and intake door motors does not operate normally.)

GO TO 9.
9. CHECK MODE DOOR MOTOR AND AIR MIX DOOR MOTOR OPERATION
1. Turn ignition switch OFF.
2. Disconnect intake door motor connector.
3. Reconnect air mix door motor (driver side, passenger side) connectors.
4. Turn ignition switch ON.
5. Confirm operation of mode door motor and air mix door motor (driver side, passenger side).
OK or NG
OK >> [Mode and air mix door motor (driver side, passenger side) operate normally.]

Replace intake door motor.
NG >> [Mode and air mix door motor (driver side, passenger side) does not operate normally.]

Replace unified meter and A/C amp.