display INFINITI QX4 2001 Factory Service Manual

RHA464GA
RHA858H
MAIN POWER SUPPLY AND GROUND CIRCUIT CHECKNBHA0037Component DescriptionNBHA0037S01Automatic Amplifier (Auto Amp.)NBHA0037S0101The auto amplifier has a built-in microcomputer which processes
information sent from various sensors needed for air conditioner
operation. The air mix door motor, mode door motor, intake door
motor, blower motor and compressor are then controlled.
The auto amplifier is unitized with control mechanisms. Signals
from various switches and Potentio Temperature Control (PTC) are
directly entered into auto amplifier.
Self-diagnostic functions are also built into auto amplifier to provide
quick check of malfunctions in the auto air conditioner system.
RHA464GA
RHA867H
Potentio Temperature Control (PTC)NBHA0037S0102The PTC is built into the A/C auto amp. or Display & NAVI control
unit. It can be set at an interval of 0.5ÉC (1.0ÉF) in the 18ÉC (65ÉF)
to 32ÉC (85ÉF) temperature range by pushing the temperature but-
ton. The set temperature is digitally displayed.
TROUBLE DIAGNOSES
A/C System (Cont'd)
HA-72

RHA051GE
DIAGNOSTIC PROCEDURENBHA0041SYMPTOM: Ambient sensor circuit is open or shorted. (or
þ
is indicated on the display as a result of conducting Self-
diagnosis STEP 2.)
1 CHECK VOLTAGE BETWEEN AMBIENT SENSOR HARNESS CONNECTOR AND BODY GROUND
Disconnect ambient sensor harness connector.
Do approx. 5 volts exist between ambient sensor harness terminal No. 1 and body ground?
RHA052G
YesorNo
Ye s©GO TO 2.
No©GO TO 4.
2 CHECK AMBIENT SENSOR CIRCUIT BETWEEN AMBIENT SENSOR AND AUTO AMP. (LCU)
1. Disconnect auto amp. (LCU) harness connector.
2. Check circuit continuity between ambient sensor harness terminal No. 2 and auto amp. (LCU) harness terminal No. 11
or 9.
RHA829H
Continuity should exist.
If OK, check harness for short.
OK or NG
OK©GO TO 3.
NG©Repair harness or connector.
TROUBLE DIAGNOSES
Ambient Sensor Circuit (Cont'd)
HA-130

3 CHECK AMBIENT SENSOR
Refer to HA-131.
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©Replace ambient sensor.
4 CHECK AMBIENT SENSOR CIRCUIT BETWEEN AMBIENT SENSOR AND AUTO AMP. (LCU)
1. Disconnect auto amp. (LCU) harness connector.
2. Check circuit continuity between ambient sensor harness terminal No. 1 and auto amp. (LCU) harness terminal No. 2.
RHA830H
Continuity should exist.
If OK, check harness for short.
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©Repair harness or connector.
SHA304F
COMPONENT INSPECTIONNBHA0042Ambient SensorNBHA0042S01After disconnecting ambient sensor harness connector, measure
resistance between terminals 2 and 1 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
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TROUBLE DIAGNOSES
Ambient Sensor Circuit (Cont'd)
HA-131

Temperature ÉC (ÉF) Resistance kW
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
If NG, replace ambient sensor.
RHA103G
In-vehicle Sensor Circuit
COMPONENT DESCRIPTIONNBHA0043In-vehicle sensorNBHA0043S01The in-vehicle sensor is located on instrument lower panel. It con-
verts variations in temperature of compartment air drawn from the
aspirator into a resistance value. It is then input into the auto
amplifier.
RHA636F
RHA482A
AspiratorNBHA0043S02The aspirator is located in front of heater unit. It produces vacuum
pressure due to air discharged from the heater unit, continuously
taking compartment air in the aspirator.
RHA056GH
DIAGNOSTIC PROCEDURENBHA0044SYMPTOM: In-vehicle sensor circuit is open or shorted. (or
þ
is indicated on the display as a result of conducting Self-
diagnosis STEP 2.)
TROUBLE DIAGNOSES
Ambient Sensor Circuit (Cont'd)
HA-132

3 CHECK IN-VEHICLE SENSOR
Refer to HA-135.
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 in-vehicle 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 IN-VEHICLE SENSOR CIRCUIT BETWEEN AMBIENT SENSOR AND AUTO AMP. (LCU)
1. Disconnect auto amp. (LCU) harness connector.
2. Check circuit continuity between in-vehicle sensor harness terminal No. 1 and auto amp. (LCU) harness terminal No. 3.
RHA832H
Continuity should exist.
If OK, check harness for short.
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©Repair harness or connector.
TROUBLE DIAGNOSES
In-vehicle Sensor Circuit (Cont'd)
HA-134

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

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

4 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. 1 and auto amp. (LCU) harness terminal No. 12
or 10.
RHA834H
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.
RHA835H
COMPONENT INSPECTIONNBHA0049Sunload SensorNBHA0049S01Measure voltage between auto amp. terminal 12 (10) and body
ground.
If NG, replace sunload sensor.
IWhen checking sunload sensor, select a place where sun
shines directly on it.
TROUBLE DIAGNOSES
Sunload Sensor Circuit (Cont'd)
HA-138

RHA056GI
DIAGNOSTIC PROCEDURENBHA0106SYMPTOM: Intake sensor circuit is open or shorted. (or
þ
is indicated on the display as a result of conducting
Self-diagnosis STEP 2.)
1 CHECK INTAKE SENSOR CIRCUIT BETWEEN INTAKE SENSOR AND BODY GROUND
Disconnect intake sensor harness connector.
Do approx. 5 volts exist between intake sensor harness terminal No. 2 and body ground?
RHA495G
YesorNo
Ye s©GO TO 2.
No©GO TO 4.
2 CHECK INTAKE SENSOR CIRCUIT BETWEEN INTAKE SENSOR AND AUTO AMP. (LCU)
1. Disconnect auto amp. (LCU) harness connector.
2. Check circuit continuity between intake sensor harness terminal No. 2 and auto amp. (LCU) harness terminal No. 11 or
9.
RHA836H
Continuity should exist.
If OK, check harness for short.
OK or NG
OK©GO TO 3.
NG©Repair harness or connector.
TROUBLE DIAGNOSES
Intake Sensor Circuit (Cont'd)
HA-140

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