IDX INFINITI QX4 2001 Factory Service Manual

1 CHECK IN-VEHICLE SENSOR CIRCUIT BETWEEN IN-VEHICLE SENSOR AND BODY GROUND
Disconnect in-vehicle sensor harness connector.
Do approx. 5 volts exist between in-vehicle sensor harness terminal No. 1 and body ground?
RHA477G
YesorNo
Ye s©GO TO 2.
No©GO TO 4.
2 CHECK IN-VEHICLE SENSOR CIRCUIT BETWEEN IN-VEHICLE SENSOR AND AUTO AMP. (LCU)
1. Disconnect auto amp. (LCU) harness connector.
2. Check circuit continuity between in-vehicle sensor harness terminal No. 2 and auto amp. (LCU) harness terminal No.
11 or 9.
RHA831H
Continuity should exist.
If OK, check harness for short.
OK or NG
OK©GO TO 3.
NG©Repair harness or connector.
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TROUBLE DIAGNOSES
In-vehicle Sensor Circuit (Cont'd)
HA-133

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
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TROUBLE DIAGNOSES
In-vehicle Sensor Circuit (Cont'd)
HA-135

2 CHECK SUNLOAD SENSOR CIRCUIT BETWEEN SUNLOAD SENSOR AND AUTO AMP. (LCU)
1. Disconnect auto amp. (LCU) harness connector.
2. Check circuit continuity between sunload sensor harness terminal No. 2 and auto amp. (LCU) harness terminal No. 11
or 9.
RHA833H
Continuity should exist.
If OK, check harness for short.
OK or NG
OK©GO TO 3.
NG©Repair harness or connector.
3 CHECK SUNLOAD SENSOR.
Refer to HA-138.
OK or NG
OK©1. Replace auto amp. (LCU).
2. Go to self-diagnosis step-by-step procedure (HA-45) and perform self-diagnosis STEP
2.
Confirm that code No. 20 is displayed.
NG©1. Replace sunload sensor.
2. Go to self-diagnosis step-by-step procedure (HA-45) and perform self-diagnosis STEP
2.
Confirm that code No. 20 is displayed.
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TROUBLE DIAGNOSES
Sunload Sensor Circuit (Cont'd)
HA-137

SHA930E
RHA584E
Intake Sensor Circuit
COMPONENT DESCRIPTIONNBHA0105Intake SensorNBHA0105S01The intake sensor is located on the cooling unit. It converts tem-
perature of air after it passes through the evaporator into a resis-
tance value which is then input to the auto amp.
After disconnecting intake 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 intake sensor.
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TROUBLE DIAGNOSES
Sunload Sensor Circuit (Cont'd)
HA-139

3 CHECK INTAKE SENSOR
Refer to HA-139.
OK or NG
OK©1. Replace auto amp.
2. Go to self-diagnosis step-by-step procedure (HA-45) and perform self-diagnosis STEP
2.
Confirm that code No. 20 is displayed.
NG©1. Replace intake sensor.
2. Go to self-diagnosis step-by-step procedure (HA-45) and perform self-diagnosis STEP
2.
Confirm that code No. 20 is displayed.
4 CHECK INTAKE SENSOR CIRCUIT BETWEEN AMBIENT SENSOR AND AUTO AMP. (LCU)
1. Disconnect auto amp. (LCU) harness connector.
2. Check circuit continuity between intake sensor harness terminal No. 1 and auto amp. (LCU) harness terminal No. 1.
RHA837H
Continuity should exist.
If OK, check harness for short.
OK or NG
OK©1. Replace auto amp.
2. Go to self-diagnosis step-by-step procedure (HA-45) and perform self-diagnosis STEP
2.
Confirm that code No. 20 is displayed.
NG©Repair harness or connector.
Air Mix Door Motor PBR Circuit
DIAGNOSTIC PROCEDURENBHA0050For description of mode door motor and air mix door motor circuit,
refer to HA-84.
SYMPTOM: If PBR circuit is open or shorted. (þ
oris
indicated on the display as a result of conducting Self-diag-
nosis STEP 2.)
Perform diagnostic procedure for mode door motor and air
mix door motor. Refer to HA-78.
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TROUBLE DIAGNOSES
Intake Sensor Circuit (Cont'd)
HA-141

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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TROUBLE DIAGNOSES
Multiplex Communication Circuit (Cont'd)
HA-143

SHA251FA
*1: HA-146
*2: HA-155*3: HA-157
*4: HA-114*5: HA-2
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SERVICE PROCEDURE
HFC-134a (R-134a) Service Procedure (Cont'd)
HA-145

4 CHECK ANY PART
Is there any part to be replaced? (Evaporator, condenser, liquid tank or in case there is evidence of a large amount of
lubricant leakage.)
YesorNo
Ye s©Go to ªLubricant Adjusting Procedure for Components Replacement Except
Compressorº, (HA-148).
No©Carry out the A/C performance test.GI
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SERVICE PROCEDURE
Maintenance of Lubricant Quantity in Compressor (Cont'd)
HA-147

RHA065DD
Compressor
REMOVAL AND INSTALLATIONNBHA0072
RHA892H
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SERVICE PROCEDURE
Maintenance of Lubricant Quantity in Compressor (Cont'd)
HA-149

RHA138E
IRemove the snap ring using external snap ring pliers.
RHA139E
IPulley removal
Position the center pulley puller on the end of the drive shaft,
and remove the pulley assembly using any commercially avail-
able pulley puller.
To prevent the pulley groove from being deformed, the
puller claws should be positioned onto the edge of the
pulley assembly.
RHA125F
IRemove the field coil harness clip using a pair of pliers.
RHA145E
IRemove the snap ring using external snap ring pliers.
RHA126F
INSPECTIONNBHA0075Clutch DiscNBHA0075S01If the contact surface shows signs of damage due to excessive
heat, replace clutch disc and pulley.
PulleyNBHA0075S02Check the appearance of the pulley assembly. If the contact sur-
face of pulley shows signs of excessive grooving, replace clutch
disc and pulley. The contact surfaces of the pulley assembly should
be cleaned with a suitable solvent before reinstallation.
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SERVICE PROCEDURE
Compressor Clutch (Cont'd)
HA-151