1998 NISSAN GT-R relay

TROUBLE DIAGNOSES .
CONSULT (Cont'd)
Monitored item
[Unit] signals Description
Remarks
INJ
PULSE [msec]
I
When the engine is stopped, a certain
computed value is indicated. lndicates the actual fuel injection pulse
width compensated by ECM according to
the input
siqnals.
IGN TIMING [BTDC]
I lo
lndicates the ignition timing computed by ECM according to the input signals. When the engine is stopped, a certain
value is indicated.
IACV-AACN
I%]
I lo
lndicates IACV-AACN control value com-
puted by ECM according to the input sig-
nals.
PURG VOL CN
[ONIOFF dutyj lndicates the EVAP canister purge vol-
ume control valve computed by the ECM according to the input signals. The opening becomes larger as the
value increases.
AIF
ALPHA [%]
- The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated. -- - When the engine is stopped, a certain
value is indicated.
This data also includes the data for the
air-fuel ratio learning control.
AIR COND
RLY [ONIOFF] The air conditioner relay control condition
(determined by ECM according to the
input signal) is indicated.
-- - - Indicates the fuel pump relay control con-
dition determined by ECM according to
the input signals.
The control condition of the intake valve
timing control solenoid valve is indicated.
ON
... Intake valve timing control is oper-
ating. OFF
... lntake valve timing control is not
operating.
VlAS
SN [ONIOFF] RB20DE (UB), RB25DE
Control conditions computed by ECM Solenoid valve activated: ON Solenoid valve not activated: OFF
SWRL CONT SN
[ON/OFF]
0 RB20DE (UB)
COOLING FAN
[HVLOW/O FF] RB25DE, RB25DET
The control condition of the cooling fan
(determined by ECM according to the
input signal) is indicated.
HI
... High speed operation LOW ... Low speed operation
OFF ... Stop
TURBO CONT
SN 0 RB25DET Control conditions computed by ECM
Solenoid valve activated: ON Solenoid valve not activated: OFF
PD PRESSURE
SENSOR M Refrigerant pressure sensor output volt-
age Approx. 0.36V min.
(Varies with air conditioner refrigerant
pressure)
, VOLTAGE Voltage measured by the voltage probe.
Pulse width, frequency or duty cycle
measured by the pulse probe. Only "#" is displayed if item is unable to
be measured.
r Figures with "#"s are temporary ones.
They are the same figures as an actual
piece of data which was just previously
measured.

TROUBLE DIAGNOSES
CONSULT (Cont'd)
ACTIVE TEST MODE
INJECTION I . CCohArthe amount of fuel injection
TEST ITEM
CONDITION
Engine: Return
to the original trouble
- I . Engine: After warming up, idle the
IACV-AACN
OPENING
ENG COOLANT
TEMP
IGNITION TIMING
US~~~CONSULT.
Engine: After warming up, idle the
engine.
Change the IACV-AAC valve opening
percent using CONSULT.
Engine: Return to the original trouble
conditioo
Change the engine coolant
temperature using CONSULT.
Engine: Return to the original trouble
condition
Timing light: Set Retard the ignition timing using CONSULT.
POWER BALANCE engine. A/C switch "OFF . Shift lever uNn
COOLING
FAN RB25DE, RB25DET
FUEL PUMP RELAY
VlAS SOL VALVE RB20DE (UB), RB25DE
JUDGEMENT
Cut off each injector signal one at a
time using CONSULT.
Ignition switch: ON Turn the cooling fan "ON" and "OFF
using CONSULT.
0 lgnition switch: ON (Engine stopped) . Turn the fuel pump relay "ON" and
"OFF using CONSULT and listen to
operating sound. CHECK
ITEM (REMEDY)
If trouble symptom disappears, see
CHECK ITEM. : ~,"~~,,,~scOnnectOr Oxygen sensor
Engine speed changes according to the
opening percent.
. Harness and connector IACV-AAC valve
If trouble
symp:orn disappears, see
CHECK ITEM. : Sensor 0 Fuel injectors
If trouble symptom disappears, see
CHECK ITEM. 0 Adjust ignition timing (by moving
camshaft position sensor)
Engine runs rough or dies.
Harness and connector Compression Injectors 0 lgnition coil with power transistor Spark plugs
Cooling fan moves and stops.
Hamess and connector Cooling fan motor Cooling fan relay
Fuel pump relay makes the operating
sound.
. Harness and connector Fuel pump relay
VALVE
TIMING
SOL
SWIRL CONT SOL
VALVE
0 RB20DE (UB)
SELF-LEARNING
CONT
PURG VOL CONTN
Checks control items and output circuit by arbitrary ON/OFF operation.
. In this test, the coefficient of self-learning control mixture ratio returns to the original coefficient by touching "CLEAR" on the
screen.
. Harness and connector EVAP canister purge control solenoid
valve
Vacuum hose
0 Engine: Run engine at 2,000 rpm. . Turn the EV~P canister purge control solenoid valve and using CONSULT and listen for operating
sound. EVAP
canister purge control solenoid
valve makes an operating sound. Check
vacuum signal for EVAP canister purge ~~~~~~a'cuum exists. VC OFF ... Vacuum does not exist.

TROUBLE DIAGNOSES t i
CONSULT (Cont'd) i
FUNCTION TEST MODE
CHECK ITEM (REMEDY)
FUNCTION
TEST
ITEM JUDGEMENT
CONDITION
lgnition switch: ON
(Engine stopped)
Displays the results of on board
diagnostic system.
SELF-DIAG
RESULTS Objective
system
--
ignition switch: ON
(Engine stopped)
Throttle position sensor circuit is
tested when throttle is opened and
closed fully. ("IDLE POSITION" is
the test item name for the vehicles
in which idle is selected by throttle
position sensor.) Harness and connector
Throttle position sensor (Closed
throttle position)
Throttle position sensor (Closed
throttle position) adjustment
Throttle linkage
Venfy operation in DATA
MONITOR mode.
Throttle
valve:
opened OFF
ON
CLOSED THROTTLE
POSl Throttle valve:
closed
lgnition switch: ON
(Engine stopped)
Throttle position sensor circuit is
tested when throttle is opened and
closed fully.
Harness and connector
Throttle position sensor
Throttle position sensor
adjustment
Throttle linkage
Verify operation in DATA
MONITOR mode.
Range
(Throttle
valve fully opened
- Throttle valve
fully closed) More
than 3.0V THROTTLE POSl
SEN CKT
lgnition switch: ON
(Engine stopped)
Neutral position switch circuit is
tested when shift lever is
manipulated.
lgnition switch: ON
(Engine stopped)
Fuel pump circuit is tested by
checking the pulsation in fuel
pressure when fuel tube is
pinched. Out of
N/P
positions OFF
Harness
and connector
Neutral position switch
Linkage adjustment
PARWNEUT POSl SW CKT
In
N/P positions
Harness and connector
Fuel pump
Fuel pump relay
Fuel filter clogging
Fuel level
There
is pressure pulsation on
the fuel feed hose.
FUEL PUMP
CIRCUIT
--
The valve timing control system is
diagnosed by checking for
operating sound of the solenoid
valve.
lgnition switch: ON
(Engine stopped)
Cooling fan circuit is tested when
cooling fan is rotated.
VALVE
TIMING
SN
CKT
Harness and connector
Cooling fan motor
Cooling fan relay
COOLING
FAN
CIRCUIT RB25DE, RB25DET
The cooling fan rotates and
stops every
3 seconds.
lgnition switch: ON -+ START
Start signal circuit is tested when
engine is started by operating the
starter. Battery voltage and water
temperature before cranking, and
average battery voltage, mass air
flow sensor output voltage and
cranking speed during cranking
are displayed.
Harness and connector
lgnition switch
START
SIGNAL
CIRCUIT Start
signal: OFF 3 ON

TROUBLE DIAGNOSES
Symptom Matrix Chart
RELATION BETWEEN CONTROL ITEMS AND SENSORSfACTUATORS
@: High possibility to control damage 0: Low possibility to control damage
Sensors and actuators
1$1$1$ r I I
Crankshaft position sensor 1@1@1@
Ring gear crankshaft position sensor
[RB20DE (UB)] @
Mass air flow sensor
I Engine coolant temperature sensor I 0 I @ I 0 i I
Heated oxygen sensor 0
Knock sensor
Vehicle speed sensor
e? - 01 0
Throttle position sensor 000 C. $ Turbo pressure sensor (TIC) 0 0
Refrigerant pressure sensor
START
lgnition switch
@ 0
IGN 000
Air conditioner switch
Parklneutral position switch
Power steering oil pressure switch
Electrical load switch
Battery
voltage
0
injector @GO I
I power transistor I I I Ignition system I I I lgnition coil I I I I
AAC valve
Fuel DumD relav
. . I I I
2 o ECM & IGN coil relay I@l@l@ 1 I I % Auxiliary electric fan relay 3 - 2 Air conditioner relay
Canister purge control valve
0
Variable valve timing control solenoid valve
Variable air intake control solenoid valve
, (NA) Air jet swirl control solenoid valve
[RB20DE (UB)] 0
Turbo pressure control solenoid valve
(TW
FPCM (TIC)
%' Dropping resistor (TIC) 2. I I 5 Air regulator
Canister 0

*va r TROUBLE DIAGNOSES
Symptom Matrix Chart (Cont'd)
"- RELATION BETWEEN TROUBLE SYMPTOMS AND ACTUATORS - Actuators No
Start Hard
start Rough
idle
Poor derivability Engine
stall
Symptom
. @: High possibility 0: Low possibility
Coil Open
Open
Open
Short
I Injection port Foreign
material
Ignition signal (Power
transistor drive signal)
Ignition primary signal
(Power transistor
ground)
Primary
si'de
.- c. - k Secondary side -
2 Power supply
Fuel pump relay
Auxiliary electric fan
relay
[RB25DE,
RB25DEfl
hen
Canister purge con-
trol valve
Variable valve timing
control solenoid valve
~
Variable air intake
control solenoid valve
Air jet swirl control
solenoid valve
Turbo pressure con-
trol solenoid valve
Injector ground (Total
ground) nstantaneous
reak
I ': Fast idle

TROUBLE DIAGNOSES
Symptom Matrix Chart (Cont'd)
An open circuit causes no fuel injection to the corresponding cylinder, and the heated oxygen sensor output becomes lean. When the open circuits are
observed at all cylinders, the engine will not start.
Actuator-related malfunction
Injector Symptom
characteristics and inspection hints
Drive
circuit
lgnition signal
(POW&
transistor
drive
siqnal)
(open
Injection Open
Short
Fuel pump relay
1 Open 1 Engine will not start. In case of instantaneous break, surging may occur.
A
short circuit causes continuous fuel injection to the corresponding cylinder, and
over-rich airlfuel ratio and misfire will be noted. When the short circuits are
observed at all cylinders, the engine will not start.
Foreign
material
Clogs
L
Foreign
material causes continuous fuel injection to the corresponding cylinder.
Symptoms vary with the condition how the injection port is clogged.
Aidfuel ratio
compensation factor becomes larger.
(1 10 to 125%)
Canister purge control valve Ignition primary
signal (Power
transistor ground)
Auxiliary electric fan relay
[RB25DE, RB25DETI
1 Short
Open
Open -
Open
Open
Leaks
Open
Open
lgnition coil
AAC valve
The valve purges constantly. In summertime, engine may stall at idle speed due
i to rich aidfuel ratio. In wintertime, various malfunctions may occur due to lean
airlfuel ratio.
An open circuit causes no fuel injection to the corresponding cylinder, and the '
heated oxygen sensor output becomes lean. When the open circuits are observed at all cylinders, the engine will not start. In case of instantaneous break, symptoms vary with the break time and the
vehicle's driving conditions. Light shock or surging will occur while the vehicle
is being driven.
The engine will stall when break time is long.
AAC valve is fully closed. Symptoms vary with the base engine speed. When it is
too low, engine may stall while the vehicle is decelerating or when the power
steering load or electrical load is applied.
Power
supply
s~de
primary
Second-
arY side
Power
supply
Drive
circuit
Open Open Auxiliary
electric fan will not operate even after warm-up is completed.
The valve
will not purge. Gasoline smell may be noted when the weather is hot.
Variable valve timing control
solenoid valve
Variable air intake control sole-
noid valve (NA)
Air jet swirl control solenoid
valve
[RB20DE
(UB)]
Injector ground (Total ground) lnstanta- Symptoms vary
with the break time and the vehicle's driving conditions. Surging neous break or engine stall may occur when the instantaneous break occurred during fuel
I I injection. I
Open
, Open
Short
Turbo pressure control solenoid
valve (TIC) Valve
timing not switched.
Variable air intake valve opens, and torque in low speed range is reduced.
Variable air intake valve closes, and torque in high speed range is reduced.
Open
Short Air jet
swirl control valve remains closed.
Air jet swirl control valve remains open.
Open
Open Swing valve opens earlier, and
maximum turbo pressure is reduced.
Engine will not start
because the injectors do not operate.

TROUBLE DIAGNOSES
P ECM (aTCM) InputDutput Signal Reference
Value
SIGNAL VOLTAGES MEASURED WITH OSCILLOSCOPE AND CIRCUIT TESTER
- Signal voltages measured at ECM (-TCM) terminals (terminals for engine control) with a circuit tester and
example of waveforms displayed on an oscilloscope are shown below.
For signal terminals for A/T control, refer to "AIT Trouble Diagnosis" in AT section.
Measured data are affected by many factors such as irregularity of parts, vehicle history, operating
conditions, environment, service status, and measuring instruments and methods.
Terminal
No.
RX / TX
Signal name
I nition signal 8 ower transistor
drive signal)
CH~~"N
ECM & IGN coil
relay control signal (Data
link connector for CONSULT)
Tachometer drive
signal
NOTE: Above
At idle
When cranking: Approx. 0.1 2V
At idle: Approx. 0.1 V
?pprox. 1V
,During approx. 1.5
sec. after ignition switch turned OFF: 4pprox. 1 V 1.5 sec. after ignition switch turned OFF: Battery voltage)
:RB20DE
(UB),
RB25DEJ
Approx.
1.2V
:RB25DET]
Approx.
7.2V At
approx. 2,000 rpm
Approx. 0.15
- 0.25V
Approx. 3V
voltages are measured values obtained by analog circuit tester.
EC-39

TROUBLE DIAGNOSES
ECM (-TCM) InputlOutput Signal Reference
Value (Cont'd)
d
voltages are
Terminal No. Signal name
At idle At
approx. 2,000 rpm
Approx.
12V Approx. 8V
AAC valve control
signal
[RB20DE
(UB), RB25DEl
During 5 sec. after ignition switch tumed ON: Approx. 0.25V 5 sec. after ignition switch turned ON: Battery voltage
When cranking: Approx. 0.25V At idle: Approx. 0.25V Fuel pump relay
control signal - - [RB25DETJ
During 3 sec. after ignition switch tumed ON: Approx.
0.9V
3 sec. after ignition switch tumed ON: Battery voltage
When cranking: Approx. 0.9V At idle: Approx. 0.9V
Approx. 0.9V
Air conditioner
relay control signal Air conditioner
OFF: Battery voltage
Air conditioner ON: Approx. 0.25V
MIL OFF: Battery voltage
MIL ON
RBZODE
(UB), RB25DE: Approx. 0.85V RB25DET Approx. 0.1 V
Malfunction indica-
tor lamp
lgnition switch
(START) signal
Air conditioner
switch signal Approx.
OV (Ignition
switch at START Battery voltage)
Air conditioner OFF: Approx.
4.7V Air conditioner ON: Approx. 0.1 V -
22 (CHK) Check
(Diagnosis
start)
Throttle position
sensor signal
lgnition switch
(IGN) signal CONSULT
connected: Approx. OV CONSULT not connected: Approx. OV
Accelerator pedal released: Approx. OSV Accelerator pedal fully depressed: Approx. 4.2V
(Ignition switch ON, engine not running)
lgnition switch
OFF: Approx. OV lgnition switch ON: Battery voltage Approx.
0.6 - 0.7V
24
(IGN)
Ground Approx.
OV
Power
steering oil
pressure switch
signal Steering
wheel not tumed: Approx. 4.N Steering wheel turned: Approx. OV
26
NOTE: I bove measured values obtained by analog ircuit
tester.