1998 NISSAN GT-R Service Manual

ANTI-LOCK BRAKE SYSTEM
CONSULT (Cont'd) - -
Diagnostic item
CONTROL UNIT --
BAnERY "OLTAGE
[VB-HIGH]
"OLTAGE
[VB- LO
W]
Function of calculation in ABS control unit has failed.
Diagnostic
item is detected when
...
Control unit,
control
unit
power supply
and ground
circuit
Check item
ABS control unit battery voltage
is abnormally high.
ABS control unit battery voltage is abnormally low.
. ABS MOTOR
[LOCK FAILURE] Control
unit
power supply
circuit ABS motor speed is abnormally low. AES motor,
motor relay
and circuit
1 I
'1 : ABS warning lamp turns on if a wheel or wheels spin for I0 to 80 seconds (depending on the wheel speed) with the vehicle
stuck in snow. ice, or mud. This is a normal condition.
'2: After repairing short-circuited sensor, turning ignition switch ON lights up ABS warning lamp. Check that ABS warning lamp
turns
off when the vehicle is driven at approx. 30 krnh for approx. 1 minute as shown in the self-diagnosis procedure. NOTE: If "ABSn is not displayed on "SELECT SYSTEM" screen, check ABS control unit and data link connector circuit, and make sure
of the CONSULT card number.
DATA MONITOR PROCEDURE
Refer to CONSULT Instruction Manual for details on data
monitor function.
1. Turn ignition switch OFF.
2. Connect CONSULT connector to data link connector for CON-
SULT.
3. Turn ignition switch ON.
4. Touch "START' on CONSULT screen.
5. Touch "ABS" on CONSULT screen.
If "START" is touched immediately after engine is started
or ignition switch is turned on,
"ABS" may not be dis-
played on "SELECT SYSTEM" screen. To display "ABS",
repeat the data monitor procedure from the beginning.
6. Touch "DATA MONITORn.
7. Touch "SETTING" to set recording condition.
8. Touch "AUTO TRIG", "LONG TIME" and then "ENTER".
9. Return to "SELECT MONITOR ITEM" screen and touch "CIU
INPUT ITEM", "ALL SIGNALS" or 'SELECTION FROM
MENU". Refer to "DATA MONITOR MODE" on the next page.
10. Touch "START'.
11. Display data monitor.
12. If necessary, sequentially touch "REC START, "REC STOP",
"DATA DISPLAY", "NUMBER PRINT' and "PRINT' to print out
the data.

ANTI-LOCK BRAKE SYSTEM
CONSULT (Cont'd)
DATA MONITOR MODE
MONITOR ITEM I CONDITION
FR RH SENSOR
FR
LH SENSOR
RR SENSOR Drive vehicle.
(Each wheel is rotating.)
STOP LAMP SW Turn
ignition switch ON and
depress brake pedal.
FR RH
IN SOL
FR RH OUT SOL
FR
LH IN SOL
FR LH OUT SOL
REAR IN SOL
REAR OUT SOL Ignition
switch is turned ON or
engine is running.
ACTUATOR RLY
MOTOR RLY
Ignition switch is turned ON or
engine is running.
WARNING LAMP
BATTERY VOLT
I
VOLTAGE Indicates
the voltage mea-
sured with a voltage probe.
PLS WIDTH-H
I
Refer to CONSULT Instruction
Manual.
NlSSAN
CONSULT
START I --
1 SUB MODE BR455C
$ SELECT SYSTEM 0-
ENGINE
A/T
I - ABS I
SPECIFICATION
Displays computed vehicle speed from wheel sensor signal.
Almost the same speed as speedometer.
Depress the pedal: ON
Release the pedal: OFF
EC ;
Operating conditions for each solenoid valve are indicated. ABS is AT '
not operating: OFF
Displays ON/OFF condition of ABS actuator relay.
When turning ignition switch ON,
ABS actuator relay
is operated. 2
ABS is not operating: OFF
ABS
is operating: ON
Warning lamp is turned on: ON
R8 $
Warning lamp is turned off: OFF
Power supply voltage for control unit
~~~~
ACTIVE TEST PROCEDURE
When conducting Active test, vehicle must be stationary.
Confirm that brakes have been bled completely.
When ABS warning lamp stays on, never conduct Active test.
Turn ignition switch OFF.
Connect CONSULT to Data Link Connector for CONSULT.
Start engine.
Touch "START' on CONSULT screen.
Touch
"ABS".

ANTI-LOCK BRAKE SYSTEM
CONSULT (Cont'd)
I b~ SELECT DiAG MODE 01 r SELF-DIAG RESULTS
DATA MONITOR
ACTIVE TEST
ECU
PART NUMBER I
FR RH SOL TEST
I 1 !!! SELECT MONITOR ITEM I I
I I SELECTION FROM MENU I I
I I START 1
6. Touch "ACTIVE TEST'.
7. Select active test item by touching screen.
8. Touch "START'.
9. "ACTIVE TEST" screen is displayed.
ABS solenoid valve
To check that ABS solenoid valves (inlet and outlet) operate in
the following manner, touch
"UP*, "KEEP" and "DOWN" on the
screen while observing the monitor.
Operation I UP I KEEP ( DOWN
IN ABS SN I OFF 1 ON I ON
OUTABS SN I OFF I OFF I ON*
*: Solenoid valve stays ON for 1 to 2 seconds after touching the key, and then
turns OFF.
If the active test is conducted with brake pedal depressed, the
brake pedal travel limit may change. This is a normal condition.
"TEST IS STOPPED" message is displayed 10 seconds after
the operation is started.
If the active test needs to be performed again after "TEST IS
STOPPED" is displayed, repeat step 8.

ANTI-LOCK BRAKE SYSTEM
CONSULT (Cont'd)
r I I ABS motor / a UCTIl..!E TEST fj I I Touch "ON" and "OFF on the screen to check that ABS motor - - - - -. . -
relay and ABS actuator relay operate as follows:
- - - - -- --
Operation
ABS actuator relay
brake pedal travel limit may change. This is a normal condition.
"TEST IS
STOPPED" message is displayed 10 seconds after
ABS motor relay I ON
1 the operation is started.
I
ON
ON
OFF OFF G9
ON
EG
If the active test is conducted with brake pedal depressed, the

ANTI-LOCK BRAKE SYSTEM
Self-diagnosis
DESCRIPTION
When a problem occurs in the ABS, the ABS warning lamp on the
instrument panel comes on. To actuate the self-diagnostic results
mode, ground the self-diagnostic check terminal
4 located on the
data
link
connector for
CONSULT. The ABS warning lamp, then,
flashes and indicates the location of the malfunction.
SELF-DIAGNOSIS PROCEDURE
1. Collect information on the concern from the customer, and then
perform basic inspections.
2. Drive vehicle at approx. 30 km/h for approx. 1 minute.
3. Stop vehicle and start diagnosis.
4. Turn ignition switch "OFF'.
5. Ground the self-diagnostic check terminal 4.
6. Turn ignition switch "ON" to start the self-diagnostic results
mode.
CAUTION:
Keep terminal 4 grounded during self-diagnosis.
Do not depress brake pedal. (Self-diagnosis would not
start.)
Do not start engine. (Self-diagnosis would not start.)
7. After 3 or 4 seconds, ABS warning lamp starts blinking to indi-
cate the malfunction code No.
The indication terminates after 5 minutes. Turning the ignition
switch from
"OFF" to "ON" resumes blinking the indication.
8. Verify the location of the malfunction with "MALFUNCTION
CODUSYMPTOM CHART", BR-16. Then make the necessary
repairs.
9. After the malfunctions are repaired, erase the malfunction
codes stored in the control unit. Refer to "HOW
TO ERASE
SELF-DIAGNOSTIC RESULTS" on the next page.
10. Rerun the self-diagnostic results mode to verify that the mal-
function codes have been erased.
11. Disconnect the check terminal from the ground. The self-diag-
nostic results mode is now complete.
12. Drive vehicle at approx. 30 km/h for approx. I minute, and then
check that the ABS warning lamp is off.
HOW TO READ SELF-DIAGNOSTIC RESULTS
(Malfunction codes)
Determine the code No. by observing the time and the fre-
quency that the
ABS warning lamp blinks ON and OFF.
When multiple malfunctions occur at a time, up to three code
numbers can be stored; the latest malfunction will be indicated
first.
The indication begins with the start code No. 12. A maximum
of three code numbers appear in the order of the latest one
first. The indication then returns to the start code No.
12 to
repeat.
The start code No. 12 is only indicated repeatedly when there
is no malfunction.

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'.

ANTI-LOCK BRAKE SYSTEM
Self-diagnosis (Cont'd)
MALFUNCTION CODEISYMPTOM CHART
Malfunction code No. Malfunctioning
part ABS warning
lamp
ON
Fail-safe
operation
18 1 Different number of teeth of sensor rotors 1010
2 1
26 I Front left wheel sensor (short-circuiQ.4 1010
- --
22
25
3 1 I Rear wheel sensor (open-circuit) 1010
Front right wheel sensor (open-circuit)
32 Rear wheel sensor (short-circuit)'4 1 0 1 0
Front right wheel sensor (short-circuit)'4
Front left wheel sensor (open-circuit)
41
I Front right outlet ABS solenoid valve and circuit 1010
0 0
0
0
0
0
- -
42
-- - -
46 Front left inlet ABS solenoid valve and circuit 0 1 0
45 Front
left outlet ABS solenoid valve and circuit
55
1 Rear outlet ABS solenoid valve and circuit 1010
Front right inlet ABS solenoid valve and circuit
56
1 Rear inlet ABS solenoid valve and circuit 1010
0
57 1 Power supply (Low or high voltage)*2 I 0 I -'I
0
0
0
I At self-diagno- ( ABS control unit or data link connector for CONSULT is poorly 1 I
61
63
At self-diagno-
I ABS control unit
sis only
ABS
actuator motor or motor relayg3
ABS
actuator relay
No indication
I I ABS control unit1ABS actuator relay is stuck to OFFJABS I Stays ON power supply circuit, ABS actuator relay drive side power sup-
lgnition switch
ply (coil side) circuit, and ABS warning lamp circuit are
short-
circuited./ABS control unit connector is disconnected or poorly
0
0
I
sis only
Ignition switch
ON
I I connected. I I
0
0
connected.
ABS control
unit1Fuse is blown or ABS warning lamp has an
open circuit.
- -- '1: Fail-safe operation does not activate. A signal from ABS control unit suspends ABS control operation. Brakes operate con-
ventionally. After specified power supply voltage resumes, ABS warning lamp goes out, allowing for ABS control operation. '2: The code No. does not indicate a malfunction related to the ABS control unit. Do not replace the ABS control unit even if the code No. appears. '3: The code No. can sometimes appear when the ABS motor ground circuit is loose or disconnected. When it appears, always
check the ground circuit for improper installation.
'4: ABS warning lamp turns on if a wheel or wheels spin for 10 to 80 seconds (depending on the wheel speed) with the vehicle
stuck in snow, ice, or mud. This is a normal condition. After repairing short-circuited sensor, turning ignition switch ON lights
up
ABS warning lamp. Check that ABS warning lamp turns off when the vehicle is driven at approx. 30 krnlh for approx. 1 minute as shown in the self-diagnosis procedure.

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.