2001 INFINITI QX4 Ac system

Memory Function
TROUBLE DIAGNOSIS PROCEDURE FOR MEMORY FUNCTION=NBHA0102SYMPTOM:
IMemory function does not operate.
Inspection FlowNBHA0102S01Without Navigation SystemNBHA0102S0101
RHA885H
*1: HA-72 *2: HA-66 *3: HA-45
TROUBLE DIAGNOSES
Memory Function
HA-126

With Navigation SystemNBHA0102S0102
RHA886H
*1: HA-72 *2: HA-66 *3: HA-45
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
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BT
SC
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IDX
TROUBLE DIAGNOSES
Memory Function (Cont'd)
HA-127

ECON (ECONOMY) Mode
TROUBLE DIAGNOSIS PROCEDURE FOR ECON (ECONOMY) MODE=NBHA0103SYMPTOM:
IECON mode does not operate.
Inspection FlowNBHA0103S01Without Navigation SystemNBHA0103S0101
SHA920EA
*1: HA-72 *2: HA-66 *3: HA-45
TROUBLE DIAGNOSES
ECON (ECONOMY) Mode
HA-128

With Navigation SystemNBHA0103S0102
RHA887H
*1: HA-72 *2: HA-66 *3: HA-45
RHA050G
Ambient Sensor Circuit
COMPONENT DESCRIPTIONNBHA0039The ambient sensor is attached in front of the driver's side con-
denser. It detects ambient temperature and converts it into a resis-
tance value which is then input into the auto amplifier.
AMBIENT TEMPERATURE INPUT PROCESSNBHA0040The automatic amplifier includes a ªprocessing circuitº for the ambi-
ent sensor input. However, when the temperature detected by the
ambient sensor increases quickly, the processing circuit retards the
auto amp. function. It only allows the auto amp. to recognize an
ambient temperature increase of 0.33ÉC (0.6ÉF) per 100 seconds.
As an example, consider stopping for a cup of coffee after high
speed driving. Although the actual ambient temperature has not
changed, the temperature detected by the ambient sensor will
increase. This is because the heat from the engine compartment
can radiate to the front grille area, location of the ambient sensor.
GI
MA
EM
LC
EC
FE
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PD
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TROUBLE DIAGNOSES
ECON (ECONOMY) Mode (Cont'd)
HA-129

RHA060GB
COMPONENT INSPECTIONNBHA0045In-vehicle SensorNBHA0045S01After disconnecting in-vehicle sensor harness connector, measure
resistance between terminals 1 and 2 at sensor harness side, using
the table below.
Temperature ÉC (ÉF) Resistance kW
þ15 (5) 12.73
þ10 (14) 9.92
þ5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
If NG, replace in-vehicle sensor.
RHA639F
Sunload Sensor Circuit
COMPONENT DESCRIPTIONNBHA0046The sunload sensor is located on the right defroster grille. It detects
sunload entering through windshield by means of a photo diode.
The sensor converts the sunload into a current value which is then
input into the auto amplifier.
SUNLOAD INPUT PROCESSNBHA0047The auto amp. also includes a processing circuit which ªaverageº
the variations in detected sunload over a period of time. This pre-
vents drastic swings in the ATC system operation due to small or
quick variations in detected sunload.
For example, consider driving along a road bordered by an occa-
sional group of large trees. The sunload detected by the sunload
sensor will vary whenever the trees obstruct the sunlight. The pro-
cessing circuit averages the detected sunload over a period of
time, so that the (insignificant) effect of the trees momentarily
GI
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TROUBLE DIAGNOSES
In-vehicle Sensor Circuit (Cont'd)
HA-135

obstructing the sunlight does not cause any change in the ATC
system operation. On the other hand, shortly after entering a long
tunnel, the system will recognize the change in sunload, and the
system will react accordingly.
SHA301FA
DIAGNOSTIC PROCEDURENBHA0048SYMPTOM: Sunload sensor circuit is open or shorted. (or
þ
is indicated on the display as a result of conducting Self-
diagnosis STEP 2.)
1 CHECK SUNLOAD SENSOR CIRCUIT BETWEEN SUNLOAD SENSOR AND BODY GROUND
Disconnect sunload sensor harness connector.
Do approx. 5 volts exist between sunload sensor harness terminal No. 1 and body ground?
RHA062G
YesorNo
Ye s©GO TO 2.
No©GO TO 4.
TROUBLE DIAGNOSES
Sunload Sensor Circuit (Cont'd)
HA-136

RHA888H
Multiplex Communication Circuit
DIAGNOSTIC PROCEDURENBHA0118SYMPTOM:
IA/C system does not come on.
IA/C system can not controlled.
1 CHECK CIRCUIT CONTINUITY BETWEEN DISPLAY & NAVI CONTROL UNIT AND AUTO AMP.
Check circuit continuity between each terminal on Display & Navigation control unit and on auto amp.
RHA889H
Continuity should exist.
If OK, check harness for short.
OK or NG
OK©GO TO 2.
NG©1. Repair harness or connector.
2. Go to ªOPERATIONAL CHECKº, HA-66.
Confirm that A/C system is in good order.
2 CHECK MULTI-PLEX COMMUNICATION SIGNAL
Do approx. 3.5 volts exist between Display & NAVI control unit harness terminal Nos. 37, 38 and body ground?
RHA890H
YesorNo
Ye s©GO TO 3.
No©1. Replace auto amp.
2. Go to ªOPERATIONAL CHECKº, HA-66.
Confirm that A/C system is in good order.
TROUBLE DIAGNOSES
Multiplex Communication Circuit
HA-142

3 CHECK MULTIPLEX COMMUNICATION SIGNAL
Do approx. 3.5 volts exist between auto amp. harness terminal No. 40 and body ground?
RHA891H
YesorNo
Ye s©INSPECTION END.
No©1. Replace Display & NAVI control unit.
2. Go to ªOPERATIONAL CHECKº, HA-66.
Confirm that A/C system is in good order.
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IDX
TROUBLE DIAGNOSES
Multiplex Communication Circuit (Cont'd)
HA-143