1998 NISSAN GT-R wheel

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
System Description (Cont'd)
Parts that make throttle control inoperative
Malfunction code No.
11
12
13
91
32 I
Throttle motor return spring (Return spring is bro-
ken.) Malfunctioning part
Throttle position sensor circuit
Throttle motor sensor circuit Circuit for
the communication line
(DKR line)
between
TCSIABS control unit and throttle control
unit
Actuator system (Motor circuit is open or throttle
L I
22
23
24
Parts that make throttle control operative
motor intermittently works.)
Throttle motor drive system (overcurrent)
Throttle motor relay circuit (shorted)
Throttle motor relay circuit (open)
System Diagram
Secondary throttle posrt~on sensor value - - C; Front nght C CI) - ul wheel sensor , Throttle control unrt 0 - CI, -
$ Rear ngh:
g 5 wheel sensor c 0 m E
000000
Total control stgnal for engrne, AIT and TCS/ABS (multrpie communication)
TCSlABS control unrt
Rear lett
whee! sensor
TCS OFF swtch
Front left
wheei sensor
-+ SLIP 1ndrca:or Lamp '
----c TCS OFF rndcator lamp
c A9S warnlns lamp BR-0227D
Malfunction code No.
31
33
Malfunctioning parts
Starter signal circuit (shorted)
Paridneutral
position switch circuit (open or
shorted)

TCSfABS SYSTEM
Component Parts
Location
[El TCSIABS
Rear wheel sensor
Throttle motor relay
Front right wheel
senso
Throttle control unit
Front left wheel sensor
@ RH side of engine compartment
// /LA~A~~~~
RH side of rear suspension t%ernb&- /
I Rear wheel sensor connector
Engine compartment control unit
-- -- -- -
- - LH side of engine compartment
Behind LH side lower fi

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

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
CONSULT for TCS/ABS Control Unit Control
System (Cont'd)
SELF-DIAGNOSTIC RESULTS MODE
Diagnostic item Diagnostic item is detected when ...
Circuit for front right wheel sensor is open. Or an abnormally high input voltage is
entered due to short to battery.
Circuit for front left wheel sensor is open. Or an abnormally high input voltage is entered
due to short to battery.
Circuit for rear right wheel sensor is open. Or an abnormally high input voltage is enterec
due to short to battery. Check
item
FR RH SENSOR
[OPEN]
FR LH SENSOR
[OPEN]
REAR SENSOR
[OPEN]
RR LH SENSOR
[OPEN] Circuit for rear left
wheel sensor is open. Or an abnormally high input voltage is entered
due to short to battery.
Front right wheel sensor is short-circuited or shorted to ground, or gap between the
wheel sensor and the sensor rotor is large. An abnormally low input voltage is entered
and input signal is abnormal.
FR
RH SENSOR
[SHORT) Wheel
sen-
sor circuit
FR LH SENSOR
[SHORTJ Front
left wheel sensor is short-circuited or shorted to ground, or gap between the wheel
sensor and the sensor rotor is large. An abnormally low input voltage is entered and
input signal is abnormal.
Rear right wheel sensor is short-circuited or shorted to ground, or gap between the
wheel sensor and the sensor rotor is large. An abnormally low input
vottage is entered
and input signal is abnormal.
Rear left wheel sensor is short-circuited or shorted to ground, or gap between the wheel
sensor and the sensor rotor is large. An abnormally low input voltage is entered and
input signal is abnormal.
Circuit for front right inlet ABS solenoid valve is open, or an output voltage is much lower
than the specified value due to short to ground.
Circuit for front
left inlet ABS solenoid valve is open, or an output voltage is much lower
than the specified value due to short to ground.
RR
RH SENSOR
[SHORTJ
RR LH SENSOR
[SHORV
FR RH IN ABS SOL
[OPEN]
FR LH
IN ABS SOL
[OPEN]
REAR IN ABS SOL
[OPEN] Circuit
for rear inlet ABS solenoid valve is
open, or an output voltage is much lower than
the specified value due to short to ground.
-
FR RH IN ABS SOL
[SHORT]
- - - -- - - - -
Circuit for front right inlet ABS solenoid valve is shorted, or an output voltage is much
higher than the specified value due to short to battery.
Circuit for front left inlet ABS solenoid valve is shorted, or an output voltage is much
higher than the specified value due to short to battery.
Circuit for rear inlet ABS solenoid valve is shorted, or an output voltage is much higher
than the specified value due to short to battery.
Circuit for front right outlet ABS solenoid valve is open, or an output voltage is much
lower than the specified value due to short to ground.
Circuit for front left outlet
ABS solenoid valve is open, or an output voltage is much lower
than the specified value due to short to ground.
FR
LH IN
ABS SOL
[SHORTJ
REAR IN ABS SOL
[SHORT] Solenoid and
circuit
FR RH OUT ABS SOL
[OPEN]
FR LH OUT ABS SOL
[OPEN]
REAR
OUT ABS SOL
[OPEN]
- --
Circuit for rear outlet ABS solenoid valve is open, or an output voltage is much lower
than the specified value due to short to ground.
Circuit for front right outlet ABS solenoid valve is shorted, or an output voltage is much
higher than the specified value due to short to battery.
Circuit for front left outlet
ABS solenoid valve is shorted, or an output voltage is much
higher than the specified value due to short to battery.
Circuit for rear outlet
ABS solenoid valve is shorted, or an output voltage is much higher
than the specified value due to short to battery.
ABS motor turns ON when control unit sends OFF signal. ABS motor circuit is open or
shorted to ground.
ABS motor turns OFF when control unit sends ON
signzl. Relay control wire is broken.
FR RH OUT ABS SOL
[SHORT]
FR LH OUT ABS SOL
[SHORT]
REAR
OUT ABS SOL
[SHORT]
ABS MOTOR
[ON FAILURE]
ABS motor,
motor relay
and circuit
ABS
MOTOR
[OFF FAILURE]

TCS/ABS SYSTEM
CONSULT
for TCSfABS Control Unit Control
System (Cont'd)
DATA MONITOR MODE --
I ~elect-monitor item I
Display
signals Selection from
Remarks
menu
FR RH SEN
[kmlh] Displays vehicle speed computed based on
front right wheel sensor signal.
zc
FR LH SEN [kmlh] Displays
vehicle speed computed based on
front left wheel sensor signal.
AT
Displays vehicle speed computed based on
rear right wheel sensor signal.
Displays vehicle speed computed based on
rear left wheel sensor signal.
REAR
SEN
[kmlhll
RR LH SEN
lkmlhll
FIR IN SOL [ON-OFF]
I O
FIR OUT SOL [ON-OFF] /
lndicates operating condition (ONIOFF) for 87 front right inlet solenoid.
lndicates operating condition (ONIOFF) for
front right outlet solenoid.
Rs
FIL IN SOL O
A FIL OUT SOL [ON-OFF] /
lndicates operating condition (ONIOFF) for
front left inlet solenoid.
y- 13 u -:-.!
Indicates operating condition (ONIOFF) for
1 front left outlet solenoid. --
REAR IN SOL [ON-OFq / A I Indicates operating condition (ONIOFF) for
" I rear inlet solenoid.
RR OUT SOL [ON-OFF]
/
ABS ACTUATOR [ON-OFF]
- - .
O
O
0
0
ABS MOTOR [ON-OFFI I - I 0
-
lndicates operating condition (ONIOFF) for SC rear outlet solenoid.
lndicates ABS actuator relay status
(ON1
OFF). Indicates
ABS motor relay status
(ONIOFF).
Indicates stop lamp switch status
(ONIOFF).
STOP LAMP SW
[ON-OFFl
I 0 I 0
ENG SPEED SIG [RUNISTOP] I 0 I 0 0 I lndicates engine operation.
WARNING LAMP
[ON-OFF]
I - I 0 0 I lndicates ABS warning lamp status.
BATTERY VOLT
iv I
I lidicates the voltage supplied to the TCSI n
THRTL OPENING 1x1 1 0 I 0
V
0
THL OP TARGET [%I I - 1 0
ABS control unit.
Indicates throttle angle condition.
- - -
lndcates throttle control unit target angle. 0-1- -- - -- - -
lndicates the value at which fuel to ECM is
cut off.
lndicates the gear position.
lndicates TCS switch status (ONIOFF).
TCS
MODE
GEAR
1016-
0 I lndicates TCS OFF indicator lamp status.
TCS
SW [ON-OFF]*
TCS OFF LAMP [ON-OFF]
SLIP
LAMP [ON-OFF]
0 I lndicates SLlP indicator lamp status.
I I
*: The TCS switch only indicates that the switch is ON or OFF. It does not necessarily correspond to the TCS operation condi-
tion (TCS OFF indicator lamp OFF or ON).
-
0
-
-
lndicates the selector position (ONIOFF)
based on the
A/T PNP switch signal or the
neutral position switch signal.
-
0
0
0
PIN POSl SIG
[ON-OFFI
I

TCS/ABS SYSTEM
Self-diagnosis for TCS/ABS Control Unit
control System (Cont'd)
Example: Code No. 25 Front left wheel sensor (open-circutt)
lnd~cat~on
start Start code No.
12
HOW TO ERASE SELF-DIAGNOSTIC RESULTS
(Malfunction codes)
1. Turn the ianition switch "ON" and start the engine.
ABS warnlng lamp - ON
ABS warning lamp
OFF
2. Drive the iehicle at approx. 30 km/h for appfox. 1 minute to
check that there
is no other malfunction.
3. Stop the vehicle and turn the ignition switch "OFF'. I88
4. Ground the self-diagnostic check terminal 4 on the data link
connector for CONSULT.
5. Turn the ignition switch "ONn to start the self-diagnostic results /,%@A
mode.
I---------- -------------- -?-I 3 06 0.9 03C303 3 3 06 3.6 06 09 030303030303030303
Unit: seconds BRG1185D
Tens drglts Units drgits Code No. 25
I -----l
7. Under the self-diagnostic results mode, the malfunction
memory erase mode starts when the check terminal
is discon-
nected from the ground.
8. Ground the check terminal 3 times or more in succession
-.
self-d~agnosts complete
SLlP ndicator lamp i
I ON r
f OFF - c 4 i
ground J Erase -- - - - - - - - - -i - - - - ---f2.i geconds-- - - - - - - .. t mode
Malfunct~on
memory
Malfunct~on
memory
IS erase mode starts. 1s erased. BRZOO~~D
within 12.5 seconds after the erase mode starts. (Each ground-
ing must be
2 seconds or longer.)
9. Disconnect the grounding cable from the check terminal to
erase the malfunction memory and complete the
self-diagno-
-----
CAUTION:
Keep terminal 4 grounded during self-diagnosis. Do not EL
depress the brake pedal during self-diagnosis. Do not start the
engine.
6. The SLIP indicator lamp starts blinking to indicate the malfunc- SD
tion code No. 3 or 4 seconds after the self-diagnostic results
mode is started.
The indication terminates after 5 minutes. Turning the igni-
tion switch from
"OFF" to "ON" resumes blinking the indi-
cation. During the SLlP indicator lamp operation shown
above,
TCS OFF indicator lamp and ABS warning lamp are
lit.
sis.
10. Rerun the self-diagnostic results mode to verify that the mal-
function codes have been erased.
0 When the malfunction codes have been erased, the start
code No.
12 is only indicated.
11. Disconnect the check terminal from the ground. The self-diag-
nostic results mode is now complete.
12. Drive vehicle at approx. 30 kdh for approx. 1 minute, and then
check that the
TCS OFF indicator lamp, the SLlP indicator
lamp
and the ABS warning lamp are OFF.
13. Turn the ignition switch "OFF.