1998 NISSAN GT-R Service Manual

ENGINE AND EMISSION CONTROL OVERALL SYSTEM
A 1 System Description
The engine control system, which performs various controls such
as the fuel injection control and ignition timing control with a single
control unit, has been adopted.
Diagnostic system applicable to
CONSULT has been adopted for
easier inspection, service, and trouble diagnostic operations.
Description of Engine Control
I
Description \,
Performs optimum fuel injection for every operation condition for
improved exhaust performance and response.
Adopts
SOFlS (Sophisticated and Optimized Fuel Injection System)
control for optimized fuel injection.
Adopts
airbuel ratio feedback
learning control that performs
com-
0
pensation of airfiuel ratio for improved drivability when the system is
in a transitional condiiion due to sudden change in
airfiuel ratro.
Uses an ignition timing map stored in the control unit to perform
controls so that the optimum ignition timing is obtained for every
operating condition.
Performs knock control, in which the ignition timing is advancedl
retarded according to the presence of knocking, so that the
opti- 0
mum i nition timing is obtained for every operating condition and
type
oPfue1.
Performs feedback control to obtain the target idle speed for various
conditions, such as during warm-up or when the air conditioner is
actuated, via the
AAC valve that adjusts the intake air amount when
O
the throttle valve is fully closed.
Turns the fuel pump relay OWOFF according to the engine speed
Fuel
injection control
Ignition timing control
Idle
speed
control
Fuel pump drive signal. In RB25DET model, FPCM (Fuel Pump Control Modulatoi) control O
has been adopted for reduced idle noise.
Heated oxygen sensor
heater control
Air conditioner cut control
Promotes warm-up of the heated oxygen sensor for improved air1
fuel ratio feedback function. 0
Tums the air conditioner relay OFF at starting or during acceleration to reduce the engine load. 0 -- Auxiliary electric fan con-
trol
Engine,
M, TCS,ABS integrated control
Tums the auxiliary electric fan relay ONIOFF according to the - engine coolant temperature signal and air conditioner signal.
Reduces engine toque during gearshift or when TCS (Traction
Control System) is being operated via a multiplex communication
lino 0
- -
Variable valve timing con-
trol According to the engine speed and load, controls the cam phase by
hydraulic pressure to change intake valve
open/close timing for
Increased engine torque at low and middle speeds and for
enhanced
out~ut.
I o I
Canister purge control air
intake valve control
Air
jet swirl control Performs duty
control of the canister purge air according to various ooeratina conditions.
0 -r-~ e-- ---
-
Controls the intake air passage in the intake manifold collector to
increase engine torque at low and middle speeds and to enhance
output. 0
According to operation conditions, turns the air jet swirl control sole-
noid valve ONIOFF to openlclose the air jet swirl control valve
for 0
pressure control
stable combustion.
Tums the Turbo pressure control solenoid valve ONIOFF according - to operation conditions.
Ensures the vehicle's safe operation and enables the vehicle
to be
Fail-safe and backup con-
trols
Diagnostic system driven
in an emergency when any of the system major components
(microcomputer in the control unit, engine coolant temperature
0
sensor, etc.) fails.
For easier trouble diagnosis, self-diagnostic system is adopted and
the existing diagnostic system is modified so that CONSULT can be
0 used.

ENGINE AND EMISSION CONTROL OVERALL SYSTEM
RB20DE (UB)
System Diagram
c !! I-
a
5 a - w 2 LL
Malfunction indicator lamp
-!
Fuel pump control signal
Parwneutral position switch signal
C
Vehicle speed signal - - 5 Vehicle speed signal -

ENGINE AND EMISSION CONTROL OVERALL SYSTEM
System
Diagram (Cont'd)
a
E a - al 1 U.
Malfunction indicator lamp
Fuel pump control signal
+
ParWneutral position switch signal 2 - 1 F
Vehicle speed signal D 4 -
Crankshaft position sensor signal - - - m 2 c 0, Air conditioner switch signal * Y .- "Y
~ngine coolant temperature sensor signal - B * 4 C C Ignition timing control signal 0, P - ID - - Auxiliary air control signal a C - 2s
Refrigerant pressure sensor signal +
Power steering oil pressure switch signal
Variable valve timing control sign
- Variable air intake control
I I
solenoid valve control sig

ENGINE AND EMISSION CONTROL OVERALL SYSTEM
System Diagram (Cont'd)
Resistor a
I I~I I 1
w
C LLOE Malfunction indicator lamo
I Fuel DU~D control sional I Vehicle soeed sianal I
Parklneutral position switch signan I Refrigerant pressure sensor sianal
Air conditioner switch signal- rr -
- Power steering oil pressure switch signal
Crankshaft position sensor signal s - 0 Heated oxygen sensor output signal
Engine coolant temperature sensor signalC k - Mass air flow sensor signal r
- Ignition timing control signal ,- U I W Knock sensor output signal
Airlfuel
ratio control
signal-
Variable valve
timing
control
s~anal
Turbo pressure signal
Auxiliarv
air amount control
I
signal 2 L
g E8z E $, r
Air regulator
LT Turbo pressure sensor

ENGINE AND EMISSION CONTROL OVERALL SYSTEM
Component Parts Location
RB20DE (UB), RB25DE
Component name I Type I Location
I Fuel iniector I Hiah-resistance I Fuel tube
I Fuel pump I Electric, turbine I Right rear of luggage compartment (in
fuel tank)
AAC valve
IAA
unit Air reaulator
5 m 3 '
Solenoid valve (Duty control)
Wax
variable intake control solenoid valve
Variable air intake control actuator
Air jet swirl solenoid valve
[RBPODE (UB)]
Air jet swirl actuator
[RB20DE (LIB)]
Crankshaft position sensor Ring gear crankshaft position sensor
[RB20DE (UB)]
Mass air flow sensor Intake
manifold collector (Upper)
Ignition coil
Canister purge control valve
Variable valve tirnina control
solenoid valve
(? o C
Solenoid valve (ON-OFF control)
Diaphragm
Solenoid valve (ON-OFF control)
Diaphragm Photoelectric (Directly driven by cam-
shaft)
Magnetic
Hot wire
w v,
Micro-mold (Built into power transistor)
Solenoid valve (Duty control)
Solenoid valve (ON-OFF control) Upper part of rocker cover
Intake manifold collector
Lower part of intake manifold
Left front
of cylinder head
Clutch housing or converter housing
Air cleaner
Throttle position sensor [Incorporates throttle valve
switch
(All models only)]
Power steering oil pressure switch
Vehicle speed sensor
ECM
(.TCM)
ECM
& IGN coil relay Cylinder head
(Top of each spark plug)
Upper part of rocker cover
Front end of cylinder head
Engine coolant temperature sensor
Heated oxygen sensor
Knock sensor Variable
resistance
ON-OFF switch
Electromagnetic power generation
104-pin digital control
Small universal relay (2M) Throttle chamber
Thermistor
Zirconia (with heater)
Piezoelectric Rear of radiator lower hose
Transmission Passenger dashboard side
Passenger dashboard side
Behind ECM
(.TCM) Water
outlet
Exhaust manifold
Cylinder block

ENGINE AND EMISSION CONTROL OVERALL SYSTEM
Component
Parts Location (Cont'd)
" . . ., . .7
Comoonent name I TVLE a r Fuel injector High-resistance
Fuel pump
Electriclturbine
5 I unit I AAC valve I Solenoid valve (Duty control)
S Air reoulator 1 wax -1 I " - . -.
4 Ignition coil I Micro-mold (Built into power transistor)
I Canister purge control valve I Solenoid valve (Dutv control) ---- - Variable valve timing control solenold valve I Solenold valve (ONtOFF control)
Turbo pressure control solenoid valve
I Solenoid valve (OMOFF control)
Crankshaft position sensor Photoelectric
(Directly driven by cam-
shaft)
Mass air flow sensor
Hot wire
Throttle position sensor [Incorporates throttle valve
switch
(AlT model only)] Variable
resistance
Throttle motor sensor
09 Variable resistance
5 Engine coolant temperature sensor Thermistor V) Heated oxygen sensor
Zirconia (with heater)
Knock sensor Piezoelectric
Turbo pressure sensor Silicone diaphragm
Power
steering oil pressure switch
ONJOFF switch
( Vehicle speed sensor
Electromagnetic power generation
ECM
(.TCM) 104-pin digital control
Fuel pump control modulator (FPCM)
Voltage control
1 ECM L IGN co~l relay Small un~versal relay (2M) P t
.
Fuel tube
Right rear of luggage compartment (in
fuel tank)
Intake manifold collector
Cvlinder head
UOD of each soark olua)
Upper part of rocker cover
Front end of cylinder head
Next to left strut tower
Left front end of cylinder head
Air cleaner
Throttle chamber
Water outlet
Turbocharaer exhaust outlet
Cylinder
block
Upper part of rocker cover
Rear of radiator lower hose
Transmission
Passenger dashboard side
Left rear of
luaaaae comoartment
-- Passenger dashboard s~de
ECM ( TCM)

ENGINE AND E.MISSION CONTROL OVERALL SYSTEM
Vacuum
Hose Drawing
RB20DE (UB)
1. Intake manifold collector to Pressure regulator 10. Canister to Vacuum gallery
2. Intake manifold collector to Vacuum tank 11.
Air cleaner case to Vacuum gallery
3. Variable air intake control solenoid valve to Three-way 12. Vacuum tank to Three-way connector
connector
13. Air jet swirl control solenoid valve to Three-way connector 4. Air jet swirl control solenoid valve to Three-way connector
14. Air jet swirl control solenoid valve to Air jet swirl actuator
5. Variable air intake control solenoid valve to Variable air 15. Power steering air valve to Vacuum pipe
intake control actuator
6. lntake manifold collector to Fuel damper 16.
Power steering air valve to Air duct
7. Vacuum pipe to Three-way connector 17. Air jet swirl assembly to Vacuum pipe
8. Canister purge control valve to Vacuum gallery 18. Vacuum
pipe to Vacuum pipe
9. Canister purge control valve to Throttle chamber ;

A ENGINE AND EMISSION CONTROL OVERALL SYSTEM
Vacuum Hose Drawing (Cont'd)
RB25DE
+ Vacuum tank
Power steering air valve
--P Vacuum tank
lntake manifold collector
ECL178OD
1. lntake manifold collector to Pressure regulator
2. lntake manifold collector to Vacuum tank
3. Variable air intake control solenoid valve to Vacuum tank
4. lntake manifold collector to Fuel damper
5. Variable air intake control solenoid valve to Vacuum pipe
6. Canister to Vacuum gallery
7. Air cleaner case to Vacuum gallery
8. Canister purge control valve to Vacuum gallery
9. Canister purge control valve to Throttle chamber
10. Variable air intake control solenoid valve to Variable air
intake control actuator
11. Power steering air valve to Vacuum pipe
12. Power steering air valve to Air duct
13. Vacuum pipe to Vacuum pipe
14. AAC valve to Vacuum pipe