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

RHA817H
DIAGNOSTIC PROCEDURENBHA0107SYMPTOM:
IA/C system does not come on.
RHA818H
Auto Amp. CheckNBHA0107S01Check power supply circuit for auto amp. with ignition switch ON.
Measure voltage across terminal Nos. 26, 27, 33 (24, 25, 33) and
body ground.
Voltmeter terminal
Voltage
(+) (þ)
26 (24)
Body ground Approx. 12V 27 (25)
33 (33)
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TROUBLE DIAGNOSES
A/C System (Cont'd)
HA-73

SHA967EE
RHA868H
Check body ground circuit for auto amp. with ignition switch OFF.
Check for continuity between terminal Nos. 32, 14 and body
ground.
Ohmmeter terminal
Continuity
(+) (þ)
32
Body ground Yes
14 (Canada only)
If OK, check auto amp. ground circuit, see below.
IIf NG, check 7.5A fuses (Nos. 11 and 24, located in the fuse
block) and 15A fuses (Nos. 1 and 2, located in the fuse block).
IIf fuses are OK, check for open circuit in wiring harness.
Repair or replace as necessary.
IIf fuses are NG, replace fuse and check wiring harness for
short circuit. Repair or replace as necessary.
NOTE:
If OK, replace auto amp.
If NG, repair or replace harness.
TROUBLE DIAGNOSES
A/C System (Cont'd)
HA-74

Mode Door Motor
TROUBLE DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR (LAN)=NBHA0090SYMPTOM:
IAir outlet does not change.
IMode door motor does not operate normally.
Inspection FlowNBHA0090S01Without Navigation SystemNBHA0090S0101
SHA245F
*1: HA-25
*2: HA-66
*3: HA-44
*4: HA-45
*5: HA-129*6: HA-132
*7: HA-135
*8: HA-141
*9: STEP-BY-STEP PROCEDURE
(HA-45), see No. 13.*10: HA-78
*11: HA-81
*12: HA-66
*13: HA-65
*14: HA-139
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TROUBLE DIAGNOSES
Mode Door Motor
HA-75

With Navigation SystemNBHA0090S0102
RHA869H
*1: HA-25
*2: HA-66
*3: HA-44
*4: HA-45
*5: HA-129*6: HA-132
*7: HA-135
*8: HA-141
*9: STEP-BY-STEP PROCEDURE
(HA-45), see No. 13.*10: HA-78
*11: HA-81
*12: HA-66
*13: HA-65
*14: HA-139
TROUBLE DIAGNOSES
Mode Door Motor (Cont'd)
HA-76

SYSTEM DESCRIPTION=NBHA0052Component PartsNBHA0052S01Mode door control system components are:
1) Auto amp.
2) Mode door motor (LCU)
3) In-vehicle sensor
4) Ambient sensor
5) Sunload sensor
6) Intake sensor
System OperationNBHA0052S02The auto amplifier receives data from each of the sensors. The amplifier sends air mix door and mode door
opening angle data to the air mix door motor LCU and mode door motor LCU.
The air mix door motor and mode door motor read their respective signals according to the address signal.
Opening angle indication signals received from the auto amplifier and each of the motor position sensors are
compared by the LCUs in each motor with the existing decision and opening angles. Subsequently, HOT/
COLD or DEFROST/VENT operation is selected. The new selection data is returned to the auto amplifier.
RHA870H
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TROUBLE DIAGNOSES
Mode Door Motor (Cont'd)
HA-77

Mode Door Control SpecificationNBHA0052S03
RHA135G
RHA505G
COMPONENT DESCRIPTIONNBHA0053The mode door motor is attached to the heater unit. It rotates so
that air is discharged from the outlet set by the auto amplifier. Motor
rotation is conveyed to a link which activates the mode door.
RHA488GA
DIAGNOSTIC PROCEDURE FOR MODE DOOR MOTOR
AND AIR MIX DOOR MOTOR CIRCUIT
NBHA0104SYMPTOM: Mode door motor and/or air mix door motor does
not operate normally.
TROUBLE DIAGNOSES
Mode Door Motor (Cont'd)
HA-78

1 CHECK POWER SUPPLY FOR AUTO AMP. (LCU) SIDE
Do approx. 12 volts exist between auto amp. (LCU) harness terminal No. 21 and body ground?
RHA819H
NOTE:
If the result is NG or No after checking circuit continuity, repair harness or connector.
YesorNo
Ye s©GO TO 2.
No©Replace auto amp. (LCU).
2 CHECK SIGNAL FOR AUTO AMP. (LCU) SIDE
Do approx. 5.5 volts exist between auto amp. (LCU) terminals No. 16 or 14 and body ground?
RHA820H
NOTE:
If the result is NG or No after checking circuit continuity, repair harness or connector.
YesorNo
Ye s©GO TO 3.
No©Replace auto amp. (LCU).
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TROUBLE DIAGNOSES
Mode Door Motor (Cont'd)
HA-79

3 CHECK POWER SUPPLY FOR MOTOR SIDE
Do approx. 12 volts exist between door motor (LCU) harness terminal No. 21 and body ground?
RHA489GC
YesorNo
Ye s©GO TO 4.
No©Repair harness or connector.
4 CHECK SIGNAL FOR MOTOR SIDE
Do approx. 5.5 volts exist between door motor (LCU) terminal No. 16 and body ground?
RHA490G
YesorNo
Ye s©GO TO 5.
No©Repair harness or connector.
5 CHECK MOTOR GROUND CIRCUIT
Does continuity exist between door motor (LCU) harness terminal No. 32 and body ground?
RHA491G
YesorNo
Ye s©GO TO 6.
No©Repair harness or connector.
TROUBLE DIAGNOSES
Mode Door Motor (Cont'd)
HA-80

6 CHECK MOTOR OPERATION
Disconnect and reconnect the motor connector and confirm the motor operation.
OK or NG
OK (Return to operate
normally)©Poor contacting the motor connector
NG (Does not operate
normally)©GO TO 7.
7 CHECK MODE DOOR MOTOR OPERATION
1. Disconnect the mode door motor and air mix door motor connector.
2. Reconnect the mode door motor and confirm the motor operation.
OK or NG
OK (Mode door motor
operates normally)©Replace the air mix door motor.
NG (Mode door motor
does not operate nor-
mally)©GO TO 8.
8 CHECK AIR MIX DOOR MOTOR OPERATION
1. Disconnect the mode door motor connector.
2. Reconnect the air mix door motor and confirm the air mix door motor operation.
OK or NG
OK (Air mix door motor
operates normally)©Replace mode door motor.
NG (Air mix door motor
does not operate nor-
mally)©Replace auto amp.
RHA505G
CONTROL LINKAGE ADJUSTMENTNBHA0091Mode DoorNBHA0091S011. Install mode door motor on heater unit and connect it to main
harness.
2. Set up code No. in Self-diagnosis STEP 4. Refer to HA-45.
3. Move side link by hand and hold mode door in DEF mode.
4. Attach mode door motor rod to side link rod holder.
5. Make sure mode door operates properly when changing from
code No.
toby pushing DEF switch.
VENT B/L B/L FOOT D/F DEF
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TROUBLE DIAGNOSES
Mode Door Motor (Cont'd)
HA-81