NISSAN PICK-UP 1999 Repair Manual

Operational Check
The purpose of the operational check is to confirm that the sys-
tem operates properly.
CONDITIONS
lEngine running and at normal operating temperature.
PROCEDURE
1. Check memory function
a. Set the temperature 25ÉC.
b. Press OFF switch.
c. Turn the ignition OFF.
d. Turn the ignition ON.
e. Press the AUTO switch.
f. Confirm that the set temperature remains at previous tem-
perature.
g. Press OFF switch.
If NG, go to trouble diagnosis procedure for memory function
(HA-2079).
If OK, continue with next check.
2. Check blower
a. Press fan switch one time.
Blower should operate on low speed.
The fan symbol should have one blade lit
.
b. Press fan switch one more time, and continue checking
blower speed and fan symbol until all speeds are checked.
c. Leave blower on MAX speed
.
If NG, go to trouble diagnosis procedure for blower motor (HA-
2065).
If OK, continue with next check.
3. Check discharge air
a. Press mode switch four times and DEF button.
RHA517G
RHA518G
RHA519G
TROUBLE DIAGNOSESAUTO
HA-2041

b. Confirm that discharge air comes out according to the air
distribution table at left.
Refer to ªDischarge Air Flowº (HA-15 in D22 Service Manual,
Publication No. SM8E-0D22E0E).
NOTE:
Confirm that the compressor clutch is engaged (visual
inspection) and intake door position is at FRESH when the
DEF
is selected.
Intake door position is checked in the next step.
If NG, go to trouble diagnosis procedure for mode door motor
(HA-2049).
If OK, continue with next check.
4. Check recirculation
a. Press RECswitch.
Recirculation indicator should illuminate.
b. Listen for intake door position change (you should hear
blower sound change slightly).
If NG, go to trouble diagnosis procedure for intake door motor
(HA-2060).
If OK, continue with next check.
RHA520G
RHA654FH
RHA521G
TROUBLE DIAGNOSESAUTO
Operational Check (Cont'd)
HA-2042

5. Check temperature dial
a. Turn temperature dial counterclockwise until 18ÉC is dis-
played.
b. Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for insufficient cooling
(HA-2075).
If OK, continue with next check.
c. Turn temperature dial clockwise until 32ÉC is displayed.
d. Check for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for insufficient heating
(HA-2076).
If OK, continue with next check.
RHA522G
TROUBLE DIAGNOSESAUTO
Operational Check (Cont'd)
HA-2043

6. Check AUTO mode
a. Press AUTO switch.
b. Display should indicate AUTO.
Confirm that the compressor clutch engages (audio or visual
inspection).
(Discharge air and blower speed will depend on ambient,
in-vehicle, and set temperatures.)
If NG, go to trouble diagnosis procedure for A/C system (HA-
2045).
If OK, continue with next check.
Then if necessary, go to trouble diagnosis procedure for magnet
clutch (HA-2068).
7. Check FRESH switch
a. Press FRE switch.
FRESH indicator should illuminate.
b. Listen for intake door position change. (You should hear a
slight change in blower sound.)
If NG, go to trouble diagnosis procedure for intake door motor
(HA-2060).
If OK, continue with next check.
8. Check A/C switch
a. Press A/C switch.
A/C indicator should illuminate.
b. Confirm that the compressor clutch is engaged.
If NG, go to trouble diagnosis procedure for A/C system (HA-
2045).
If OK, continue with next check.
If all operational check are OK (symptom cannot be duplicated),
go to ªIncident Simulation Testº (GI section) and perform test as
outlined to simulated driving conditions environment. If symptom
appear, refer to ªSYMPTOM TABLEº (HA-2040) and perform
applicable trouble diagnosis procedures.
RHA523G
RHA524G
RHA525G
TROUBLE DIAGNOSESAUTO
Operational Check (Cont'd)
HA-2044

A/C System
TROUBLE DIAGNOSIS PROCEDURE FOR A/C SYSTEM
SYMPTOM:
lA/C system does not come on.
Inspection flow
*1: HA-2046 *2: HA-2041 *3: HA-2046
COMPONENT DESCRIPTION
Automatic amplifier (Auto amp.)
The 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 pro-
vide quick check of malfunctions in the auto air conditioner sys-
tem.
Potentio temperature control (PTC)
The PTC is built into the A/C auto amp. It can be set at an inter-
val of 1ÉC in the 18ÉC to 32ÉC temperature range by turning the
temperature dial. The set temperature is digitally displayed.
SHA354F
RHA470H
TROUBLE DIAGNOSESAUTO
HA-2045

MAIN POWER SUPPLY AND GROUND CIRCUIT
CHECK
Power Supply Circuit Check
Check power supply circuit for air conditioner system.
Refer to EL section (ªWiring Diagramº, ªPOWER SUPPLY
ROUTINGº).
DIAGNOSTIC PROCEDURE
SYMPTOM: A/C system does not come on.
Auto amp. check
Check power supply circuit for auto amp. with ignition switch ON.
Measure voltage across terminal Nos.
V1,V2,V20and body
ground.
Voltmeter terminal
Voltage
Å@
V1
Body ground Approx. 12VV2
V20
RHA632G
RHA633GA
TROUBLE DIAGNOSESAUTO
A/C System (Cont'd)
HA-2046

Mode Door Motor
TROUBLE DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR
SYMPTOM:
lAir outlet does not change.
lMode door motor does not operate normally.
Inspection flow
*1: HA-15 in D22 Service
Manual, Publication No.
SM7E-0D22G1
*2: HA-2041
*3: HA-2035
*4: HA-2036*5: HA-2037
*6: HA-2038
*7: HA-2081
*8: HA-2083
*9: HA-2085
*10: HA-2087*11: HA-2049
*12: HA-2036
*13: HA-2051
*14: HA-2041
*15: HA-2040
SHA343F
TROUBLE DIAGNOSESAUTO
HA-2047

SYSTEM DESCRIPTION
Component parts
Mode door control system components are:
1) Auto amplifier
2) Mode door motor
3) In-vehicle sensor4) Ambient sensor
5) Sunload sensor
6) Intake sensor
System operation
The auto amplifier computes the air outlet conditions according to the ambient temperature and the in-ve-
hicle temperature. The computed outlet conditions are then corrected for sunload to determine air outlet
through which air is discharged into the passenger compartment.
Mode door control specification
COMPONENT DESCRIPTION
The 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.
RHA471H
RHA384H
RHA472H
TROUBLE DIAGNOSESAUTO
Mode Door Motor (Cont'd)
HA-2048

DIAGNOSTIC PROCEDURE
SYMPTOM: Mode door motor does not operate normally.
CHECK MODE DOOR MOTOR POSI-
TION SWITCH.
1. Set up code No.
in Self-diagnosis
STEP 4.
2. Disconnect auto amp. harness connec-
tor after turning ignition switch OFF.
3. Check if continuity exists between ter-
minal Nos.
V29,V31of auto amp. har-
ness connector and body ground.
4. Using above procedure, check for conti-
nuity in other modes, as indicated in
chart.
OK
cNG
Disconnect mode door
motor harness connector.
Note
CHECK BODY GROUND
CIRCUIT FOR MODE
DOOR MOTOR.
Does continuity exist
between mode door motor
harness terminal No.
V17
and body ground?
Yes
Reconnect auto amp. har-
ness connector.
CHECK POWER SUPPLY
FOR MODE DOOR
MOTOR CONTROL CIR-
CUIT.
Do approx. 5 volts exist
between mode door motor
harness terminals and body
ground?
Yes No INSPECTION END
Reconnect
mode door
motor har-
ness con-
nector.
VAVB
(Go to next page.)
Code No.Condi-
tionTerminal No.
Conti-
nuityÅ@
VENTV29orV31
Body
groundYesorB/LV29orV30
FOOTV30orV31
D/FV31orV32
DEFV30orV32
Terminal No.
Voltage
Å@
V1
Body
groundApprox. 5VV2
V3
V4
V5
V6
Note:
If the result is NG or No after checking circuit continuity, repair harness
or connector.
RHA473H
RHA474H
RHA475H
RHA476H
.
.
.
.
.
..
TROUBLE DIAGNOSESAUTO
Mode Door Motor (Cont'd)
HA-2049

VAVB
Note
CHECK MODE DOOR MOTOR POSITION
SWITCH.
Set up Self-diagnosis STEP 4.
Measure voltage across auto amp. har-
ness terminals and body ground.
OK NGCheck circuit continuity
between each terminal on
auto amp. and on mode
door motor.
If OK, check harness for
short.
OK
Replace auto amp.
Replace mode door
motor.
CHECK FOR OUTPUT OF AUTO AMP.
Do approx. 10.5 volts exist between auto
amp. harness terminals No.
V15andV16
when code No. is switched from ªºto
ª
º or when code No. is switched from
ª
ºtoªº?
Yes
cNo
Replace auto amp.
Replace mode door motor.
Note:
If the result is NG or No after checking circuit continuity, repair harness
or connector.
Code No.Condi-
tionTerminal No.
@Å
V29V30V31V32
VENT 0V 5V 0V 5V
Body
ground
orB/L 0V 0V 5V 5V
FOOT 5V 0V 0V 5V
D/F 5V 5V 0V 0V
DEF 5V 0V 5V 0V
0V: Approx. 0V
5V: Approx. 5V
Terminal No.
Conti-
nuity
Å@
Auto
amp.Mode door
motor
Yes
V29V2
V30V3orV6
V31V1orV4
V32V5
Code No.Mode
door
motor
operationTerminal
No.Voltage
V
V15V16
®VENT®
B/LÅ@
Approx.
10.5
®DEF®
VENT@Å
þ Stop þ þ 0
RHA477H
RHA478H
RHA479H
..
.
.
.
.
TROUBLE DIAGNOSESAUTO
Mode Door Motor (Cont'd)
HA-2050