1998 NISSAN GT-R sensor

TROUBLE DIAGNOSES - Supplemental Restraint System (SRS)
Air bag module
side connector
Component Parts Inspection
SPIRAL CABLE
Disconnect the spiral cable connectors from air bag module
and air bag sensor unit.
Check continuity between terminals.
1 - 1, 2 - 2: Continuity shouid exist.

FULLY AUTOMATIC AIR CONDITIONER
System Description
The fully automatic air conditioner system utilizes sensors to detect the in-vehicle temperature, ambient
temperature, temperature of air passing through the evaporator, and
sunload. The detected values are
compared with the temperature adjustment dial setting, and calculated by the microcomputer within the
automatic amplifier. The air inlet and outlet temperatures and airflow rate are adjusted in order to main-
@ tain the in-vehicle temperature.
When an abnormal pressure occurs within the cooler cycle [gauge pressure: approx.
2.7 MPa (28 kg/
cm2G)
or higher; or approx. 0.18
MPa
(1.8
kg/cm2-G)
or lower] the refrigerant pressure sensor operates,
Ec
and stops the compressor.
The
ECM turns off the air conditioner relay, and stops the compressor during engine high load.
The blower fan motor utilizes
a brushless motor, and controls the airflow with a built-in IC that recognizes AT
the driver signal (pulse) from the automatic amplifier.
Step-motor type actuators are employed for intake door, mode door, and air mix door. They are rotated in
response to the signal (pulse) step quantity transmitted from the automatic amplifier to control the target
BR
door position.

FULLY AUTOMATIC AIR CONDlTlONER
Component Parts Location
Intake door actua:or
,
Sunload sensor
Controller
B&wer temperature sensor
fan motor
@ Radiator core lower support I
Front defros!er grille (left)
1 ,?efros:er gnlie (left) t I
0 Blower fan motor relay
Engine room, right relay box I / Air conditioner relay I
Blower and cooling unit
I Blower fan motor
? Ar condlboner relay
@ Refrigerant
pressure sensor @ Compressor @ Ambtent sensor
a Liquid tank I @ Englne room. front left
I
Blower and cooling unit
lnta Instrument panel, center I
7 IJj Cluster
lid A 0 Fuse block, rear face 1

FULLY AUTOMATIC AIR CONDITIONER
Circuit
Diagram
Blower tan motor relay
Rear defogger
A Combination meter (meter UU) output * I Rear defogger relay - Rear defogger display inpui
I Compressor
Blower
fan driver signal Refrigerant Pressure sensor
Actuator driver power source
lntake driver
1 lntake driver 2 lntake driver 3 lntake driver 4
lntake door actuator NP ON output NP display input
Lighting
SW (1 step)
Y-lkEka Air mix door actuator
Illumination
power
source
Air mix driver 1 Air mrx drive: 2 Air mix driver 3 Air mix driver 4
Mode driver 1 1 Mode driver 2 Mode driver 3 Mode driver 4
INCAR In-vehicle sensor
Ambienl sensor
Sunload sensor
AM B
Water TEMP
SUN
INTAKE
Sensor around
lluminatron
groun:!
iND
Automatic
amp!iher

FULLY AUTOMATIC AIR CONDITIONER
Automatic Amplifier Input /Output Signal
Specifications
Measurement condition I Terminal
No. Specification
v Signal
name
Ignition
I Operation or condition
switch
OFF
I - I Approx. 12
Battery
power source
Ignition power source
lllumination
ON
I - I Approx. 12
- I Lighting switch: 1 step 1 Approx. 12
ON r Lighting switch: 1 step I Approx. o
6 1 Rear defogger ON output signal Rear
defogger switch: ON
Rear defogger switch: OFF 1
Approx. 0
Approx.
5
Rear defogger switch: ON
Rear defogger switch: OFF
1
7
Approx. 12
Approx. 0
Thermal transmitter 8 1 Rear defogger
display input signal
Compressor: ON
Compressor:
OFF
Approx. 0
Approx.
5 Compressor ON signal
ON
-I-- - - - I Approx. 0 10 1 Ground
AfP display output signal (only
when connected) Blower
fan motor: ON
Blower fan motor:
OFF
Approx. 0
Approx.
5
12 1 Actuator driver power source
ON I - 1 Approx. 12
1 3 1 ACC power source ACC I - I Approx. 12
Right after temperature adjustment
dial operation
Air mix
door actuator driver signal
Fan control signal
Fan speed: Manual
1st
ON I - I Approx. 0
21
': Refer to "Component
Parts Inspectionn.
Sensor ground

FULLY AUTOMATIC AIR CONDITIONER
Automatic Amplifier Input /Output Signal
Terminal
No. Measurement condition
Specification V Signal name
Ignition
switch Operation
or condition
Right after mode switch (air outlet switch) operation
I
Mode door actuator driver signal
Right after
FRE switch or REC
switch operation 24
I
26 I Ambient sensor
lntake door actuator driver signal
Approx.
0
Approx. 5
A/P ON output (only when con-
'' / nected) Blower fan
motor: ON
Blower fan motor: OFF
Right after mode switch (air outlet
switch) operation
Mode door actuator driver signal
Right after
FRE switch or REC
switch operation -1 lntake door actuator driver signal
33 1 In-vehicle sensor
34 I Sunload sensor
35 1 lntake air temperature sensor
Right after FRE switch or REC
switch operation
36
*: Refer to "Component Parts Inspection".
lntake door actuator driver signal

FULLY AUTOMATIC AIR CONDITIONER
Trouble Diagnosis
by Gauge Pressure
Connect the manifold gauge to the cooler cycle (service valve). Speculate and correct the root cause and
trouble location based on the cooler cycle pressure.
Probable cause
lnsufficient cooling
by con-
denser
Radiator fan malfunction
lmproper air guard attach-
ment
Clogged or dirty condenser
fins Corrective action
Symptom Cycle status
Repair or replace faulty parts.
Clean or repair the condenser
Pressure retums to normal
when water is splashed on the
condenser. fins.
Both high- and low-pressures
are high.
Recover all refrigerant. Re-
vacuum and charge to appro-
priate amount.
Refrigerant
over-charge
When the compressor is
stopped, the pressure drops
suddenly approx.
2 kg/cm2.
Then, the pressure drops
gradually. Recover
all refrigerant. Re-
vacuum and charge to appro-
priate amount.
Air is mixed
in the cooler cycle.
High-pressure is too high.
Temperature differences occurs
where the high-pressure pipe is
crushed or clogged. Crushed
or clogged high-pres-
sure pipe between the com-
pressor and condenser
High-pressure
is high, and
low-
pressure is too low. Repair or replace
faulty part.
Evaporator outlet is not cooled. Clogged
expansion valve
Gas leak at temperature sen-
sor
Clogging due to foreign mat-
ter
There
is a temperature differ-
ence at the liquid tank outlet
pipe, or liquid tank is covered
with frost. Remove
foreign matter in
expansion valve, or replace.
Liquid tank malfunction
(clogged strainer) Replace
liquid tank.
Both high- and low-pressures
are low. (Sometimes the low
pressure is negative.)
lmproper attachment or failure
of intake air temperature sen-
sor thermistor Replace
intake air temperature
sensor, or repair
thermistor
attachment position.
Evaporator
outlet pipe is cov-
ered with frost (no airflow).
I Inspect for refrigerant leakage.
There is some temperature dif-
ference between compressor
high- and low-pressure pipes. Recover
all refrigerant.
Re-
lnsufficient refrigerant vacuum and charge to appro-
priate amount.
Extract all refrigerant. Suff
i-
ciently vacuum and remove
moisture. Charge to appropri-
ate amount. At this time,
replace the liquid tank without
fail.
Sometimes, the evaporator out-
let is not cooled. Sometimes,
the evaporative inlet is covered
with frost. Moisture
is mixed in the cooler
cycle. (Clogging due to frozen
moisture in the expansion
valve)
Sometimes
high-pressure is
low, and low-pressure is nega-
tive.
When the compressor is
stopped, the pressures equal-
ize. There is no temperature
difference between the com-
pressor high-pressure pipe and
low-pressure pipe. Compressor
malfunction
(com-
I
pression defect)
Valve damage or failure
Faulty gasket Replace
the compressor.
High-pressure
is low, and
low-
pressure
is high.
HA-I 0

FULLY AUTOMATIC AIR CONDITIONER
Trouble Diagnosis by Self-diagnosis Function
There are 5 steps in the self-diagnosis: to check for any sensor failure, and to check that a given control sig-
nal is transmitted to each output device.
Diagnosis
content
- - -
Diagnostic
item
i Step I I Step 2 - - - - - - - --
Each sensor check
Indicator lamp check
Display segments Ambient sensor
0 Indicator lamp In-vehicle sensor
lntake air tempera-
ture sensor
Sunload sensor Step
3
Each
actuator check
and reset check display for each
sen-
lntake door actuator
Air mix door actua-
tor Mode door actuator
lntake door actuator
Air mix door actua-
tor
Mode door actuator
Blower fan motor
Compressor
Air purifier (only
when connected)
Ambient sensor
In-vehicle sensor
lntake air tempera-
ture sensor
SELF-DIAGNOSIS OPERATION PROCEDURE R8
Switching to self-diagnosis mode
Turn the temperature adjustment dial all the way to the left.
Start the engine with the ignition switch from OFF position. Within 10 seconds, press and hold the OFF
switch for more than approx. 5 seconds, to start the self-diagnosis step 1.
Self-diagnosis completion EL
a Turn the ignition switch OFF.
Turn the AUTO switch ON.
Switching between self-diagnosis steps
Use the temperature adjustment dial to switch between self-diagnosis steps 1 to 5.
Temperature adjustment dial (turn clockwise): Step
1-5
Temperature adjustment dial (turn counterclockwise): Step
5- 1
a Refer to "SELF-DIAGNOSIS DISPLAY ITEM" for the diagnosis contents of each step.