1999 NISSAN PICK-UP Repair Manual

SYSTEM DESCRIPTION
Component parts
Air mix door control system components are:
1) Auto amplifier
2) Air mix door motor (PBR)
3) In-vehicle sensor4) Ambient sensor
5) Sunload sensor
6) Intake sensor
System operation
Temperature set by Potentio Temperature Control (PTC) is compensated through setting temperature cor-
rection circuit to determine target temperature.
Auto amplifier will operate air mix door motor to set air conditioning system in HOT or COLD position,
depending upon relationship between conditions (target temperature, sunload, in-vehicle temperature and
ambient temperature) and conditions (air mix door position and intake air temperature).
When target temperature is set at 18ÉC (65ÉF) or 32ÉC (85ÉF), air mix door opening position is fixed in full
cold position or full hot position.
Air mix door control specification
RHA482H
RHA457H
TROUBLE DIAGNOSESAUTO
Air Mix Door Motor (Cont'd)
HA-2053

COMPONENT DESCRIPTION
The air mix door motor is attached to the heater unit. It rotates
so that the air mix door is opened or closed to a position set by
the auto amplifier. Motor rotation is then conveyed through a
shaft and the air mix door position is then fed back to the auto
amplifier by PBR built-in air mix door motor.
RHA483H
TROUBLE DIAGNOSESAUTO
Air Mix Door Motor (Cont'd)
HA-2054

DIAGNOSTIC PROCEDURE
SYMPTOM: Air mix door motor does not operate normally.
IS PBR OPERATING NORMALLY?
Refer to Self-diagnoses STEP 2.
Yes
cNo
VA(Go to next page.)
CHECK FOR OUTPUT OF AUTO AMP.
Set up Self-diagnosis STEP 4.
Do approx. 10.5 volt exist between air mix
door motor harness terminals No.
V1and
V2when code No. is switched from ªº
to ª
º or when code No. is switched
from ª
ºtoªº?
Yes
cNo
Disconnect auto amp. and
air mix door motor harness
connectors.
Note
Check circuit continuity
between auto amp. har-
ness terminal No.
V5
(V6) and air mix door
motor harness terminal No.
V1(V2).
Continuity should exist.
If OK, check harness for
short.
OK
Replace auto amp.
Replace air mix door motor.
Note:
If the result is NG or No after checking circuit continuity, repair harness
or connector.
Code
No.Air mix
door
opera-
tionTerminal No.
Voltage
V
V1V2
®Cold®
HotÅ@
Approx.
10.5
®Hot®
Cold@Å
þ Stop þ þ 0
RHA959FA
RHA516H
RHA517H
.
.
.
.
TROUBLE DIAGNOSESAUTO
Air Mix Door Motor (Cont'd)
HA-2055

VA
CHECK PBR CIRCUIT BETWEEN PBR
AND AUTO AMP.
Disconnect air mix door motor harness
connector.
Do approx. 5 volts exist between air mix
door motor harness terminal No.
V3and
body ground?
Yes
cNo
Disconnect auto amp. har-
ness connector.
Note
Check circuit continuity
between air mix door motor
harness terminal No.
V3and auto amp. harness ter-
minal No.
V7.
Continuity should exist.
If OK, check harness for
short.
OK Disconnect auto amp. harness connector.
Note
Check circuit continuity between air mix
door motor harness terminal No.
V5and
auto amp. harness terminal No.
V24.
Continuity should exist.
If OK, check harness for short.
OK
Replace auto amp.
Note
Check circuit continuity between air mix
door motor harness terminal No.
V4and
auto amp. harness terminal No.
V22.
Continuity should exist.
If OK, check harness for short.
OK
CHECK PBR.
(Refer to HA-2057.)
OK
cNG
Replace air mix door motor
(PBR).
Replace auto amp.
Note:
If the result is NG or No after checking circuit continuity, repair harness
or connector.
RHA518H
RHA519H
RHA520H
RHA521H
.
..
.
.
.
.
.
TROUBLE DIAGNOSESAUTO
Air Mix Door Motor (Cont'd)
HA-2056

COMPONENT INSPECTION
PBR
Measure voltage between terminalsV3andV4at vehicle har-
ness side.
CONTROL LINKAGE ADJUSTMENT
Air mix door (Water cock)
1. Install air mix door motor on heater unit and connect it to
main harness.
2. Set up code No.
in Self-diagnosis STEP 4. Refer to
HA-2038.
3. Move air mix door lever by hand and hold it in full cold posi-
tion.
4. Attach air mix door lever to rod holder.
5. Make sure air mix door operates properly when changing
from code No.
toby pushing DEF switch.
Full cold Full hot
6. Set up code No.in Self-diagnosis STEP 4.
7. Attach water cock cable to air mix door linkage and secure
with clip.
8. Rotate and hold water cock lever AND plate in the full cold
position (CLOCKWISE completely).
9. Attach water cock cable to plate and secure with clip (white
mark on cable housing should be centered under the retain-
ing clip).
10. Check that water cock operates properly when changing
from code No.
toby pushing DEF switch. (After sev-
eral cycles, water cock lever should be midpoint of plate
opening when code No.
is set.)
RHA522H
RHA566F
AHA853
TROUBLE DIAGNOSESAUTO
Air Mix Door Motor (Cont'd)
HA-2057

Intake Door Motor
TROUBLE DIAGNOSIS PROCEDURE FOR INTAKE DOOR
SYMPTOM:
lIntake door does not change.
lIntake door motor does not operate normally.
Inspection flow
*1: HA-2035
*2: HA-2036
*3: HA-2038
*4: HA-2081*5: HA-2083
*6: HA-2085
*7: HA-2087
*8: HA-2055*9: HA-2060
*10: HA-2061
*11: HA-2041
*12: HA-2040
SHA339F
TROUBLE DIAGNOSESAUTO
HA-2058

SYSTEM DESCRIPTION
Component parts
Intake door control system components are:
1) Auto amp.
2) Intake door motor
3) Mode door motor
4) In-vehicle sensor
5) Ambient sensor
6) Sunload sensor
7) Intake sensor
System operation
The intake door control determines intake door position based on the ambient temperature, the intake air
temperature and the in-vehicle temperature. When the A/C, DEFROSTER, or OFF switches are pushed, the
auto amplifier sets the intake door at the ªFreshº position.
Intake door control specification
COMPONENT DESCRIPTION
The intake door motor is attached to the intake unit. It rotates so
that air is drawn from inlets set by the auto amplifier. Motor rota-
tion is conveyed to a lever which activates the intake door.
RHA484H
RHA383H
TROUBLE DIAGNOSESAUTO
Intake Door Motor (Cont'd)
HA-2059

DIAGNOSTIC PROCEDURE
SYMPTOM: Intake door motor does not operate normally.
CHECK POWER SUPPLY FOR INTAKE
DOOR MOTOR.
Disconnect intake door motor harness
connector.
Do approx. 12 volts exist between intake
door motor harness terminal No.
V1and
body ground?
Yes
cNo
Check power supply circuit
and 7.5A fuse (No.
23,
located in the fuse block).
Note
CHECK FOR AUTO AMP. OUTPUT.
Set up Self-diagnosis STEP 4.
Measure voltage across auto amp. har-
ness terminals and body ground.
OK
cNG
Check circuit continuity
between each terminal on
auto amp. and on intake
door motor.
OK
Replace auto amp.
Replace intake door motor.
Note:If the result is NG or No after checking circuit continuity, repair harness or
connector.
Code No.Terminal No.
ConditionVoltage
VÅ@
V13
Body
groundREC0
V2312
V1412
V1320%
FRE12V230
V1412
V13
FRE12V2312
V140
0V: Approx. 0V
12V: Approx. 12V
Terminal No.
Continu-
ityÅ@
Auto amp.Intake door
motor
V13V2
YesV23V3
V14V4
SHA858EB
RHA486H
RHA642GA
RHA487H
.
.
.
TROUBLE DIAGNOSESAUTO
Intake Door Motor (Cont'd)
HA-2060