1998 NISSAN GT-R check engine

ANTI-LOCK BRAKE SYSTEM
Self-diagnosis (Cont'd)
Example: Code No. 25 Front left wheel sensor (open-ccrcuit)
lnd~cat~on
s:arl
Start code No. i2
Unit: seconds BRG1185D
ABS warnq lamp ON -
A9S warnrng lamp OFF
Self-d~agnosis complete , C ABS warning lamp !
I i I I I
................ &. j(j(?.:e~o"dd~i!~?!!f!!. . -----... .-.---.--. iiii rase 1 12.5 seconds I mode
Malfunct~on
memory Malfunction memory is Nn. erase mode starts. Is erased BRG0057C
Tens d~g~ts Un~ts digits Code No 25 I I - I
HOW TO ERASE SELF-DIAGNOSTIC RESULTS
(Malfunction codes)
r--------- -T---t----t-l-T-l-
1. Turn the ignition switch "ON" and start the engine.
-.
---------- -I--I--t--l-i-"I
2. Drive the vehicle at approx. 30 kmh for approx. 1 minute to
check that there is no other malfunction.
ST
3. Stop the vehicle.
4. Turn the ignition switch "OFF'.
5. Ground the self-diagnostic check terminal. RS'
6. Turn the ignition switch "ON" to start the self-diagnostic results
-
-.
3 06 0.9 03C303 3.3 06 0.6 0.6 09 050303030305030303
-----
mode.
CAUTION:
c--
Do not depress the brake pedal during self-diagnosis. Do not
start the engine. (The self-diagnosis
would not start.)
7. The ABS warning lamp starts to blink 3 or 4 seconds after the EL
self-diagnostic results mode is started.
8. Under the self-diagnostic results mode, the malfunction $jD
memory erase mode starts when the check terminal is discon-
nected from the ground.
9. Ground the check terminal 3 times or more in succession
within 12.5 seconds after the erase mode starts. (Each ground-
ing must
be 1 second or longer.)
10. Disconnect the grounding cable from the check terminal to
erase the malfunction memory and complete the
self-diagno-
sis. The ABS warning lamp
, then, turns off.
11. Turn the ignition switch
"OFF'.

TCSIABS SYSTEM
System
Description
ABS FUNCTION
During ABS operation, the brake pedal pulsates along with a mechanical noise. This ensures that the ABS
is working properly. mP
When starting up the engine or immediately after the vehicle starts to run, the brake pedal pulsates and G'
a motor noise from the engine compartment can be heard. They are caused by the ABS operation check
and should not be considered abnormal.
A vehicle with the ABS may stop in a longer distance than a vehicle without the ABS when the brake is
EC
applied on a bad road, gravel road, or deep fresh snow.
TCS FUNCTION
TCS/ABS control unit monitors the speed of the driving wheels through 4 wheel speed sensors. If driving
wheel slip is detected, fuel to the engine is cut
ol
and the throttle valve is adjusted so that the engine
a
torque is reduced. On vehicles with automatic transmission, transmission shift schedule is also changed
to control the rear wheel driving torque, which results
in the reduction of wheel slip. This system enables
the throttle valve to be controlled so that optimum engine torque can be achieved in accordance with the
driver's acceleration request.
The driver may not feel satisfied with acceleration on some road surfaces. This poor acceleration occurs
because the operating TCS gives priority to maintaining optimum traction. Therefore, this condition should
R8
be considered normal.
When shiftdown is made or the acceleration pedal is depressed while the vehicle is driven on the road
surface that has different friction coefficients, the TCS may operate temporarily.
r-- 4 Lrd[-i
On vehicles with manual transmission, the SLlP indicator lamp and the TCS OFF indicator lamp may light
up when the engine is about to stall in the conditions shown below.
If the lamps go off when engine speed
increases, there is no problem in the system.
At start, the engine almost stalls and the engine speed is much lower than the idle speed.
The vehicle is driven at an extremely low speed with a high-speed gear engaged.
The clutch has been engaged until the vehicle almost stops. 8D
FAIL-SAFE FUNCTION
ABS system
If any malfunction is detected in the system, the ABS warning lamp, the TCS OFF indicator lamp and the SLlP
indicator lamp in the instrument panel is turned on with the TCSIABS deactivated and the vehicle's brake sys-
tem reverts to normal operation.
TCS system
If any malfunction is detected in the system, both the SLlP indicator lamp and the TCS indicator lamp on the
instrument panel light up and the TCS is shut down. The vehicle operates in the same manner as a vehicle
without the
TCS, while the ABS is operational.
If there is a malfunction in the throttle control system, the TCS becomes inoperative while the ABS
remains functional.
When fail-safe operation is activated, perform the self-diagnosis procedure for the TCSIABS first.
Refer to
BR-27 for details.

TCSIABS SYSTEM
Control Unit
InputlOutput Signal Specifications
USING CIRCUIT TESTER
TCS/ABS control unit - -
To perform the following inspection, the ignition switch should be turned ON with TCS/ABS control unit con-
nector and actuator connector properly connected.
I
TCS/ABS contro! unit connector
Terminal No.
P Front right wheel I
Item
sensor
I
Specifications'l
Rear right wheel Wheels are turning (Approx.
30 km/h)'3: Pulse generates.
Front: Approx. 200
Hz
Rear: ADDrox. 200 Hz I . , sensor
Rear left wheel
sensor
I
I
Brake pedal is depressed: Battery voltage (Approx. 12V)
Stop lamp signal Brake pedal is not depressed: Less than approx. 2V
Actuator relay is activated (with engine running): Less than approx.
2V
Actuator relay Actuator relay
is not activated (with fail-safe function activated and engine
not running): Battery voltage (Approx.
12V)
ABS motor is running (in CONSULT active test mode): Battery voltage
ABS motor monitor (Approx. 12V)
ABS motor is stopped (with ignition switch ON): Approx. OV
SLIP
indicator
SLIP
indicator lamp
ON'S: OV
lamp
SLIP
indicator lamp
OFF'5: Battery voltage (Approx. 12V)
TCS OFF indicator TCS OFF indicator lamp
ON'4: OV
lamp TCS OFF indicator lamp
OFF'4: Battery voltage (Approx. 12V)
TCS OFF switch TCS OFF switch is pressed: Approx. OV
signal TCS OFF switch is not pressed: Approx. 4
- 5V
Engine speed sig-
nal Pulse generates.
Refer to EC section
("ECM.TCM Input/Outout Reference Value")
Total control signal
(Multiple communi-
cation) for engine,
A/T and TCSIABS Check item (Refer-
ence)
Wheel sensors
and circuit Stop lamp switch
and circuit
ABS actuator relay
and circuit
ABS motor monitor
circuit
SLlP indicator
lamp and circuit
TCS OFF indicator
lamp and circuit
TCS OFF switch
and circuit
Engine speed sig-
nal circuit
Circuit for total
control signal (Mul-
tiple communica-
tion) for engine, A/T and TCSIABS

TCS/ABS SYSTEM
Control Unit InputlOutput Signal Specifications
(Cont'd)
Terminal No.
Specifications'l
- - --
Check item (Refer-
ence)
- - -
Body
ground
-
Approx. 7V - - or higher Communication
line circuit between
TCSIABS control
unit and throttle
control unit
DKV
(throttle angle
output)
Acceleration pedal is released: approx. 1 ms (reference)
ABS warning lamp ABS warning
lamp
and circuit 4B3 warning lamp 0Nr2: Approx. OV
4BS
warning lamp 0FF72: Battery voltage (Approx. 12V)
cictuator
relay is activated (with engine running): Battery voltage
(Approx.
12V)
ktuator
relay is not activated (with fail-safe function activated and engine
70t
running): Approx.
OV
ABS warning lamp
and circuit,
ABS
actuator relay and
circuit
Actuator relay
monitor
48s
motor is running (in
CONSULT active test mode): Less than approx.
2V
4BS motor is stopped: Battery voltage (Approx. 12V)
TCS is not activated: ABS
motor, motor
relay and circuit
ABS
motor relay
Approx. 7V - -
OV I I Communication
line circuit between TCSfABS control
unit and throttle
control unit
DKR
(throttle
motor target angle
signal) Approx. 9 ms (Reference)
Front
right inlet
solenoid
Front right outlet
solenoid
4ctuator
is activated (in CONSULT active test mode), or actuator relay is
lot
activated (with fail-safe function activated and engine not running):
4pprox.
OV
4ctuator
is not activated and actuator relay is activated (with vehicle
stopped and engine running): Battery voltage (Approx.
12V)
Rear inlet solenoid
Rear outlet
sole- ABS solenoid and
circuit
Front left inlet
solenoid
Front left outlet
solenoid
Battery gnition switch
ON: Baitery voltage
(Approx. 12V) Control
unit power
supply circuit
'1: Do not force to oDen a connector terminal when usina a circuit tester for ins~ection. '2: ABS warning lamp ON: When the ignition switch is t6ned ON (before startirig the engine) or a malfunction is detected
ABS warning lamp OFF: When the engine has started (with the system in normal condition)
'3: Tire pressure must be in accordance with specification. '4: TCS OFF indicator lamp ON: When the ignition switch is turned ON (before starting the engine), a malfunction is detected,
or TCS OFF switch is turned ON TCS OFF indicator lamp OFF: When the engine has started (with the system in normal condition) and the TCS OFF switch
is off '5: SLlP indicator lamp ON: When the ignition switch is turned ON (before starting the engine) or a malfunction is detected
SLlP
indicator lamp OFF: When the engine has started (with the system in normal condition) and the TCS is inoperative

TCS/ABS SYSTEM
Control
Unit InpuVOutput Signal Specifications
(Cont'd)
Throttle control unit
Terminal No.
Specifications*
item Check
item (Refer-
ence)
Throttle angle sig-
nal Ignition switch
ON
Throttle valve is fully closed: Approx.
0.5V
Throttle valve is fully open: Approx.
4.2V
Throttle motor sen-
sor
Throttle motor angle signal Throttle
position
sensor circuit and
ECM
I
Throttle motor sen-
sor and circuit R8 Engine is idling: Approx. 4.4V
I
I Throttle motor
TCS switch signal Engine
is idling: Approx.
3.4V
lgnition switch ON: Approx. 5V
Throttle control
unit power supply angle
signal and
MA
circuit
TCS switch signal
circuit
EL
Body
jround
- - -- -- - - - --
lgnition switch ON: Battery voltage (Approx. 12V)
Throttle control
unit power supply
Throttle motor relay
Sensor battery
voltage
Throttle control
unit power supply
Throttle motor relay Throttle
control
unit power circuit @J
1
Throttle control
unit power circuit
lgnition switch
ON: Battery voltage (Approx.
12V)
Throttle motor relay and circuit
lgnition
switch ON: Approx.
OV
Throttle position
sensor power cir-
cuit
lgnition
switch ON: Approx. 5V
lgnition switch ON: Battery voltage (Approx. 12V) Throttle control
unit power circuit
lgnition switch ON: Battery voltage (Approx. 12V)
I
Throttle motor
relay
and circuit
Start signal lgnition
switch START (Disconnect ECM-TCM connector or ECM connec-
tor.): Approx.
10V
*: Do not force to open a connector terminal when using a circuit tester for inspection. Start
signal circuit
and ECM

TCSlABS SYSTEM
Control Unit InputfOutput Signal Specifications
(Cont'd)
USING CONSULT
Indicated are the controi unit computed data. If the output circuit (harness) should be open or short-
circuited, correct values may be displayed.
TCS/ABS control unit
Display
I Vehicle is stationary.
REVOLUTION SENSOR
W/hI
STOP LAMP SW [ON-OFF] Check
item (Reference)
Data monitor
the
same 'peed Wheel sensor circuit
as speedometer (within
~onttor
ltem
Wheel
speed'l
Vehicle is
driven.'l
Condition
Brake pedal is
Brake pedal is not
depressed.
Engine is stopped.
Engine is running at
more than
400 rpm.
Actuator (solenoid) is
activated (at CONSULT Specifications
Brake pedal status
-1 Engine speed signal cir-
cuit
ENG
RPM SIGNAL
[STOP-RUN] Engine operation
active test), or actuator
relay is not activated
(with fail-safe function
activated and engine not
running). Solenoid circuit
IN
ABS SOLENOID
[ON-OFF]
Solenoid status Actuator (solenoid) is
not
activated and actuator
relay
is activated (with
vehicle stopped and
engine running).
OUT
ABS SOLENOID
[ON-OFF] OFF
Actuator relay is acti-
vated (with engine run-
ning).
ABS ACTUATOR RELAY
[ON-OFF]
- Actuator relay and circuit
Actuator
relay status
Actuator relay is not acti-
vated (with fail-safe
function activated and
engine not running).
Motor relay and motor
are activated (at CON-
SULT active test).
Motor relay and motor
are not activated. OFF
I ABS
motor, motor relay
ABS MOTOR
RELAY
[ON-OFF]
Motor
relay
and motor
status
OFF and circuit
ABS warning lamp cir-
cuit
Controi unit power
sup-
WARNING LAMP
[ON-OFF]
4BS
warning lamp
sta-
:us'2
Warning lamp ON Warning lamp OFF
'ewer supply voltage
~rovided for control unit
BATERY
BOLT [V] Ignition switch ON
Acceleration pedal is not
depressed. (Ignition
switch
ON)
10 - 16V
I
Communication line cir-
cuit between TCS/ABS
control unit and throttle
I - 10096 control unit ply circuit and ground
circuit
rhrottle
angle condition
linked with acceleration
~edal)
THRTL OPENING
[%]
Acceleration pedal is
depressed. (Ignition
switch ON)

TCS/ABS SYSTEM
Control Unit Input/Output Signal Specifications
(Cont'd)
THRTL OPENING TAR-
GET
[%]
Display Monitor item
Motor throttle angle con-
dition
TCS
MODET3
TCS OFF LAMP Data monitor I Condition
Specifications
TCS is inoperative.
TCS is operational.
Communication line
cir-
TCS is inoperative.
Number of cylinders to cuit between
TCS/ABS
which fuel is cut off control unit and
I.z /LT TCS is operational.
ECM-TCM or ECM
GEAR
TCS
SW
TCS OFF indicator lamp
TCS OFF indicator lamp
status
1 1 lEi3FF indicator amp
TCS OFF indicator lamp
@
Check item (Reference)
SLlP LAMP
0%
0 - 100%
Gear selection
TCS OFF switch status (ONIOFF)
P/N POSITION SIGNAL Communication line cir-
@
cuit
between TCSIABS
control unit and throttle
control unit
lzc
SLlP indicator lamp is / ow
TCS OFF switch circuit ST
I
1: 1st gear 2: 2nd gear 3: 3rd gear
4: 4th gear 5: 5th gear
SLIP
indicator lamp
sta-
cuit
TCS switch ON
TCS switch OFF
PNP switch signal or
neutral position switch
signal status (ONIOFF) ON
OFF
SLlP indicator lamp is
ON.
( A/T selector position: I I
I %~hift position: I ON
ON
SLIP indicator lamp cir-
1 Other than Neutral I 1
Neutral
A/T selector position:
Other than N and P
MA' shift position:
A/T PNP switch or neu-
tral position switch circuit
OFF
'1: Tire pressure must be in accordance with specification.
'2: ABS warning lamp ON: When the ignition switch is turned ON (before starting the engine) or a malfunction is detected ABS warning lamp OFF: When the engine has started (with the system in normal condition) '3: TCS mode: 0 - 24, number of cylinders to which fuel is cut off x 4
Throttle control unit
THRTL POS SEN
Display
TH MOTOR VOLT Monitor item I Sensor
voltage (V)
Sensor voltage
(V)
Throttle valve is fully
I Approx. 0.5V closed.
Engine is idling.
I
Data monitor
Approx. 3.4V
Condition
TH OPEN CONT Specifications
Motor throttle target
angle signal (ms)
NEUT
POSl
SW
START
SIGNAL
ONIOFF TCS
is inoperative
Shift (selector) lever is in
parkheutral
position. Approx.
9 ms Check
item (Reference)
ON
1
Throttle position sensor
circuit
ONIOFF Throttle motor sensor
circuit
Communication line cir-
cuit between
TCS/ABS
control unit and throttle
control unit
Start signal circuit
ParWneutral position
switch circuit
Ignition switch
ON
I

TCSlABS SYSTEM
Precautions for Trouble
Diagnosis
After performing trouble diagnosis, be sure to erase trouble stored in memory.
Refer to "CONSULT for
TCS/ABS Control Unit Control System"
(BR-27), "Self-diagnosis for TCSIABS
Control Unit Control System"
(BR-34), "CONSULT for Throttle Control Unit Control System" (BR-37) or
"Self-diagnosis for Throttle Control Unit Control System"
(BR-41).
The concerns that are difficult to duplicate may be caused by faulty electrical connections. Move harnesses
or harness connectors by hand to check if there is any poor mating of connector halves or faulty connec-
tion. Do not force to open a connector terminal when using a circuit tester for inspection.
Read GI section thoroughly in advance and make sure of all the general precautions.
Basic Inspection
BASIC INSPECTION 1 - Brake fluid level and leakage
1. Check brake fluid level in reservoir tank. Replenish brake fluid if necessary.
2. Check for leakage at or around brake piping and ABS actuator. If leakage or seepage is noted, proceed
as follows:
If ABS actuator connectors are loose, tighten to specified torque. Recheck to ensure that leakage is no
longer present.
If flare nut threads at piping connectors or actuator threads are damaged, replace faulty parts with new
ones. Recheck to ensure that leakage is no longer present.
If brake fluid leaks through areas other than actuator connectors, wipe off using a clean cloth. Recheck
for leakage or seepage. If necessary, replace faulty parts with new ones.
If brake fluid leaks at or seeps through ABS actuator, wipe off using a clean cloth.
Recheck for leakage or seepage. If necessary, replace ABS actuator with new one.
CAUTION:
ABS actuator cannot be disassembled. Do not attempt to disassemble it.
3. Check brake disc rotors and pads for proper operation.
BASIC INSPECTION 2 - Loose power line terminal
Check battery terminals (positive and negative) and battery mounting (ground) for looseness. If necessary,
tighten to specified torque. Check the battery for lower voltage.
BASIC INSPECTION 3 - SLlP indicator lamp, TCS OFF indicator lamp and ABS warning
lamp
Turn ignition switch "ON" to ensure that TCS OFF indicator lamp lights up. If TCS OFF indicator lamp does
not light, check TCS OFF indicator lamp circuit.
Turn ignition switch
"ON" to ensure that SLlP indicator lamp lights
up. If SLlP indicator lamp does not light,
check SLlP indicator lamp circuit.
Turn ignition switch "ON" to ensure that ABS warning lamp lights up. If ABS warning lamp does not light,
check ABS warning lamp circuit.
Check that the SLlP indicator lamp and the ABS warning lamp go off approx.
1 second after the engine
has started. If either of the lamps still remains on, perform the self-diagnosis for TCSIABS control unit
control system and the self-diagnosis for throttle control unit control system.
After driving vehicle at approx. 30
km/h
for approx.
1 minute, check to ensure that the SLlP indicator lamp
and the ABS warning lamp are off. If either of the lamps still remains on, perform the self-diagnosis for
TCS/ABS
control unit control system and the self-diagnosis for throttle control unit control system.
Check that the TCS OFF indicator lamp turns ON and OFF when the TCS OFF switch is turned to
ON
and OFF respectively, with the engine running. If the lamp status does not correspond to the switch
position, check the TCS OFF switch circuit.
Check that the TCS OFF indicator lamp goes off when the engine has started with the TCS OFF switch
OFF. If the TCS
OFF indicator lamp does not go off even 10 seconds after the engine has started, per-
form the self-diagnosis for TCSIABS control unit control system and the self-diagnosis for throttle control
unit control system.
After driving vehicle at approx.
30 kmlh for approx. 1 minute with the TCS OFF switch OFF, check to ensure
that the TCS OFF indicator lamp is off. If the TCS OFF indicator lamp lights up, perform the
self-diagno-
sis for
TCS/ABS
control unit control system and the self-diagnosis for throttle control unit control system.
After performing self-diagnosis procedures, be sure to erase trouble stored in memory.