engine NISSAN GT-R 1998 Service Manual

ELECTRIC SUPER HlCAS
Control Unit
Input/Output Signal Specifications
(Cont'd)
USING CONSULT
The displayed output signals represent the control unit com-
puted data. If the output circuit (harness) should
be open,
correct values may be displayed.
Monitor item
VHCL SPEED SE
[km/hj
STOP LAMP SW
[ON-OFF] Data monitor
I Condition
Specification
--
STEERING ANG Steering
wheel is turned right Steering angle (degrees) mea-
[R/Ll or left. sured from neutral position
NEUTRAL SIG Steering wheel is in neutral When neutral: ON
[ON-OFF] position
or turned right or left. When
turned (right or left): OFF
Brake pedal operation Check
item
Vehicle is running or driving
wheels are turning.
Steering angle sensor circuit
Approximately
equal to speed-
ometer reading
When pedal is depressed: ON
When pedal is not depressed:
I OFF
In neutral position:
Approx.
2.4V Vehicle
speed sensor circuit
Stop lamp switch circuit
ENGINE SPEED
[r~ml
1"l I Actuator is operating in active I In right lock position:
test. Engine
is running.
Approx. 4.4V
in left lock position:
Approx.
0.4V
Rear steering angle sensing
system
Approximately
equal to tachom-
eter reading
POWER STR SOL
[A1
Wiring
in ECM-HICAS control
unit
MOTOR CURRENT
PI
Vehicle speed is changed from
0 to 100 krnh.
HlCAS RELAY
[ON-OFF]
FAILSAFE
[ON-OFF] At
0 km/h:
Approx. 1.1 0A
At
100 krn/h: Approx. 0.48A
WARNING LAMP
[ON-OFF] System related to power steer-
ing solenoid output signal
RR ST
ANG-VOL
[Vl
MOTOR VOLTAGE
[vl
Actuator is operating in active
test.
Ignition switch is ON or engine
is running.
I Power supply system for
OK
if output current is detected
during operation Motor
and its power supply
system
1 signal from control unit
When ignition
switch is ON: ON
Not in operation HICAS
motor relay
System related to relay driving
Check malfunctioning parts
using self-diagnosis and data
monitor.
Approx.
5V
When warning lamp is ON: ON
When warning lamp is OFF:
OFF
Rear steering angle sensing
system Warning
lamp circuit
Power supply voltage Motor power
supply system
C/U
VOLTAGE
[VI Control unit power supply cir-
cuit
Ignition
switch is ON or engine
is running. Power
supply voltage

ELECTRIC SUPER HICAS
Preliminary
Check
1. Check HICAS actuator for improper attachment and condi-
tions.
Check the actuator for loose fasteners, damage in actuator
body, rods and dust boots, and grease leaks.
@
2. Check suspension system for improper attachment of links and
excessive play in axles.
3. Check all connectors for improper connections. yp 'SU 4. Conduct inspection using self-diagnosis function.
Trouble Diagnosis with CONSULT AT
DESCRIPTION
The trouble diagnoses have four modes: Self-diagnosis, Data B8
monitor, Active test and ECM Part Number modes.
Mode
SELF-D'AGNoSTIC
RESULTS
DATA MONITOR
ACTIVE TEST
ECM PART NUMBER
SELF-DIAG RESULTS I + DATA MONITOR
ACTIVE
TEST
ECM PART NUMBER
u
Function
Displays results of self-diagnosis.
Used to find main causes of trouble,
based on the result of self-diagnosis.
0 Monitors, records and prints the input and
output of
HICAS control unit.
Used to find main causes of trouble,
based on the result of data monitor.
Used to check the operation of actuator
by sending driving signals to it.
a Displays the part number of control unit.
I
SELF-DIAGNOSIS PROCEDURE
$ SELECT DlAG MODE u] r
After connecting CONSULT to data link connector, start the
engine.
Mode switching
Mode is switched simply by
touching the CONSULT
screen.
Touch START (on CONSULT display).
Touch
HICAS.
Touch SELF-DIAG RESULTS.
Refer to CONSULT operation manual
iiHICASJ' for details.
Display
RS
Qkl
The CONSULT screen dis-
plays the data.
EL

ELECTRIC SUPER HICAS
Trouble
Diagnosis with CONSULT (Cont'd)
SELF-DIAGNOSTIC RESULTS MOI -- - - -
Diagnostic item
Diagnostic item is detected when ...
Vehicle speed signal changes rapidly during
running.
I Remarks
VEHICLE SPEED SEN
[SIGNAL
TURN](.b)
I This code appears also when
engine is idling at
1,500 rpm
or faster for more than 10
, seconds; in this case, it does
not indicate abnormality.
Vehicle speed signal is not sensed for more
than
10 seconds while the vehicle is running
at
1,500 rpm of engine speed.
CODE
54
STEERING
ANGLE SEN
[NO ANG
SIG](.a) Steering angle does not change for a while
when vehicle is running at 60
km,h or faster.
Steering angle from neutral position is kept at
60" degrees or more for a certain time when
vehicle is running
at 50 km/h or faster.
Steering angle from neutral position is kept at
30" degrees or more while vehicle travels a
certain distance.
STEERING
ANGLE SEN
[ANG SIG
FIX](.e)
STEERING ANGLE
SEN
[ANG
F1X3O0](-g)
STEERING ANGLE SEN
[NO NEUT
SIG](.b)
No neutral signal (ON signal) is sensed while
vehicle travels a certain distance.
No neutral signal (ON signal) is sensed while
steering wheel is turned more than
360'.
No neutral signal (OFF signal) is sensed while
steering wheel is turned more than
50"
degrees.
STEERING ANGLE
SEN
[NEU SIG
OFF](.c)
STEERING
ANGLE SEN
[NEUT SIG
ON](.d) - - --
a When steering wheel
is turned 360" after the
detection of neutral signal, the neutral signal is
sensed for
a certain period of time.
STEERING ANGLE
SEN
[OFFSET
NEUTJ(.f)
For a certain
period of time, input signal from
main sensor shows abnormality against sensor
power supply voltage.
a When input signal from main sefisor shows
2.5+1 V, input signal from sub-sensor shows
abnormality against sensor power supply volt-
age for a certain period of time.
RR
ST ANGLE SENSOR
[MAIN
SIGNAL](.a)
RR ST ANGLE SENSOR
[SUB
SIGNALJ(.b)
- -
Input signals from main sensor and sub-sen-
sor show more than a certain amount of differ-
ence from each other.
The voltage is higher or lower than the stan-
dard value.
RR
ST ANGLE SENSOR
[OFFSET SIG](-C)
RR ST ANGLE SENSOR
[ABNORMAL
VOL](.d)
r
a Engine speed shows an abnormally low value
for a certain period of time when vehicle is
running at
2 krnlh or faster.
ENG
REV SIGNAL
[ABNORMAL SIGNAL]
a When HlCAS motor relay is ON, motor power
supply voltage shows an abnormally lower
value than ignition power supply voltage.
When control unit keeps motor power OFF, the
motor power voltage shows a non-zero value
for a certain period of time.
MOTOR VOLTAGE
[LOW VOLTAGE](-a)
MOTOR VOLTAGE
[BAD
OBSTRCT](.b)
When a motor current is more than IOA, the
actual output of the motor shows an abnor-
mally low value for a certain period of time.
MOTOR
OUTPUT
[ABNORML
SIG](.a)
- -
MOTOR OUTPUT
[REV CURRENTJ(-C) When motor output is kept ON, a reverse cur-
rent is flowing.

ELECTRIC SUPER HlCAS
Trouble Diagnosis
with CONSULT (Cont'd)
Diagnostic item
MOTOR OUTPUT
[NO
CURRENTJ(.d)
MOTOR OUTPUT
[OVERCU
RRENTl(.e)
MOTOR OUTPUT
[MOTOR
LOCK](.
b)
VEHICLE SPEED SEN
[RAPD SIGN CHANGE21
VEHICLE SPEED SEN
[NO
SIGNAU]
VEHICLE SPEED SEN
[NO SIGNAL31
CONTROL UNIT
[ABNORMAL
1-61
Diagnostic item is detected when ... I Remarks
When motor output is kept OFF, a current is
flowing.
When motor output is kept ON, an overcurrent
is flowing.
Signal from rear steering angle sensor does
not change for a certain period of time while a
motor current of
17A or more is flowing.
When vehicle is running, vehicle speed signal
is not sensed for a certain period of time after
it has changed rapidly.
"VEHICLE SPEED SEN [RPD SIG CHG2J"
has occurred previously, and vehicle speed
signal is not sensed for a certain period of
time.
I
'VEHICLE SPEED SEN [RPD SIG CHG2]" I I
has not occurred previously, and vehicle
speed signal is not sensed for a certain period
of time while the vehicle is running at
1,500
rpm of engine speed.
Control unit is malfunctioning.

ELECTRIC SUPER HICAS
Trouble Diagnosis with CONSULT (Cont'd)
connector for
b SELECT DlAG MODE 01 b SELF-DIAG RESULTS
DATA MONITOR
ACTIVE TEST
ECM PART NUMBER
I k SELECT MONITOR ITEM I 1
I SELECTION FROM MENU
u
DATA MONITOR PROCEDURE
1. After connecting CONSULT to data link connector, start the
engine.
2. Touch "START", "HICAS" and "DATA MONITOR".
3. Select items to be monitored.
(1) When "ALL SIGNALS" is selected, touch "START".
(2) When "SELECTION FROM MENU" is touched, "SELECT
TEST ITEM" screen appears. Touch appropriate items on that
screen,
and touch "ENTER" and "START".
(3) Touch "PRINT",
if printout is required.

ELECTRIC SUPER HtCAS
Trouble Diagnosis with CONSULT (Cont'd)
DATA MONITOR MODE
1 Monitor item (
Display
Main Menu - -
/ item I item 1
Remarks
VHCL SPEED SE (kmh) 1 0 I 0 I Shows a value calculated from vehicle speed sensor signal.
STEERING ANG After
battery has been disconnected and connected again, an
abnormal value is shown until neutral position
(0") is detected.
NEUTRAL SIG (ON-OFF)
( 0 ( 0 I Shows whether steering wheel is in neutral position (ONIOFF).
STOP
LAMP SW (ON-OFF) I 0 I 0 I Shows whether stop lamp switch is ON or OFF.
ENGINE SPEED Shows the engine speed caicuiated from crankshaft position sen-
sor signal.
1 I I
RR ST ANG.MAI (V) I 0 I 0 I Shows the output voltage from rear steering angle main sensor.
POWER STR SOL
RR
ST
ANG.SUB
(V)
Shows the control
unit's control current for power steering sole-
(')
' ' 1 noid. -- - - -- - -
MOTOR CURRENT (A) I 0 I 0 I shows the control unit's control current for HICAS motor relay.
0
HlCAS RELAY (ON-OFF) / 0 I 0 I Shows whether HlCAS motor relay is ON or OFF.
FAILSAFE
(ON-OFF)
I 0 I 0 I Shows whether fail-safe function is in operation (ONIOFF).
0
WARNING LAMP (ON-OFF) I Q I 0 ) Shows the control unit3 ON-OFF status of HlCAS warning lamp.
Shows the output
voltage from rear steering angle sub-sensor.
Shows the power supply voltage from HICAS control unit to rear
steering angle sensor.
CIU VOLTAGE (V) ( 0 I 0 I Shows the power supply voltage to HICAS control unit.
MOTOR VOLTAGE Shows the power supply voltage
from HICAS
control unit to
HlCAS motor.
- -- - -- VOLTAGE (V) I - I 0 I Shows the measured value by voltage probe.
PULSE Shows the measured
value by pulse probe.
If measurement
is
(mi, Hi and %I 1 - / 0 1 impossible, "#" appears. The "#" mark is shown also on the left of
final data until measurement is completed.

ELECTRIC SUPER HICAS
Trouble Diagnosis
with CONSULT (Cont'd)
connector for
'@g SELECT DlAG MODE
SELF-DIAG RESULTS i
DATA MONITOR
ACTIVE TEST
ECM PART NUMBER
u
1 I lhil SELECT MONITOR ITEM I 1
SELECTION FROM MENU
I Il
I
START I
ACTIVE TEST PROCEDURE
After connecting CONSULT to data link connector, start the
engine.
Touch "START", "HICAS and "ACTIVE TEST".
Touch 'SIMULATE" and "SELECT MONITOR ITEM".
Turn the steering wheel right or left to make the rear actuator
operate.
Reference values in normal condition
-- -
0" (Neutral) I 2.4V I 2.4V I No (Approx OV)
Steering angle
sensor
ECM PART NUMBER
Rear steering
angle main sensor
--
R 90"
L 90"
After connecting CONSULT to data link connector, turn ignition
switch ON.
Touch "START', "HICAS" and "ECM PART NUMBER7'.
Part number printed on the control unit label and part number
shown on the CONSULT screen are as follows:
2-door model: 28505
AAI
00
4-door model: 28505 AAll 0
Trouble Diagnosis with Self-diagnosis
Rear steering
angle sub-sensor
4.4V
0.4V
DESCRIPTION
If the system detects some error while vehicle is running, it notifies
the driver of a malfunction
by turning ON the HICAS warning lamp,
and at the same time, it halts the normal control and enters the
fail-safe mode.
Motor current
SELF-DIAGNOSIS PROCEDURE
4.4V
0.4V
1. Start the engine.
2. Within 10 seconds after the engine has started, turn the steer-
ing wheel more than
20" right-to-left and repeat this
5 times or
more, and then depress the brake pedal
5 times or more.
Yes (Variable)

ELECTRIC SUPER HICAS
Trouble
Diagnosis with Self-diagnosis (Cont'd)
DIAGNOSTIC ITEM INPUT
1. Move the vehicle one or two meters at a very low speed.
2. Turn the steering wheel more than 20" right-to-left once or
more.
Example: Motor power supply and steering
angle neutral signal are abnormal.
1s ,
2H z
ON
OFF
/ r Second / / I I display
Tens Units Tens
Units starts.
Example: Motor power supply and steering
angle neutral signal are abnormal.
1s- ,
0.8s A - ,2S , ,1.8S -
ON I-- '1 7, OFF- -.-- -
5s 55 1s 1.8s v".2S I_
/ -j- &lnd,
display
Tens Units Tens Units starts.
/
(12) (23) STE0109D
DISPLAY OF SELF-DIAGNOSTIC RESULTS
The results of self-diagnosis are shown by flash patterns of HlCAS BR
warning lamp.
Display when past data shows that fail-safe function
has been activated previously
Only an abnormal item is indicated by the pattern shown in the ~8 left figure. The pattern is repeated.
Display when past data shows that fail-safe function
has not been activated previously EL
If all items are normal, HlCAS warning lamp flashes at a fre-
quency of
4 Hz. sD
If system is in fail-safe mode, only an abnormal item is indi-
cated by the pattern shown in the left figure. The pattern
is
repeated.
MALFUNCTION CODE CHART
Malfunction code No. 1 Diagnostic item
11 I Control unit
2
1 [ ~ze speed signal
12
13
22 I Steering angle signal
Motor
power supply
Motor output --
23 ]Steering angle neutral signal
24 I Rear steering angle main sensor signal
2
5 I Rear steering angle sub-sensor signal
33
I Engine speed signal
HOW TO ERASE SELF-DIAGNOSTIC RESULTS
If past record shows that fail-safe function has been activated
previously, use CONSULT, or leave the battery disconnected for
more than
30 minutes to clear the memory.

ELECTRIC SUPER HICAS
Symptom Chart
Diagnostic item
Self-diagnosis CONSULT
-
Mal-
func- tion
code No. Diagnostic
item Diagnostic
item
Control unit CONTROL
UNIT [ABNORMAL
1-61
MOTOR VOLTAGE [LOW VOLTAGE](-a)
Motor power
supply
MOTOR VOLTAGE [BAD
OBSTRCTJ(.b)
MOTOR OUTPUT [ABNORML
SIG](.a)
- - MOTOR OUTPUT [MOTOR LOCq(-b)
MOTOR OUTPUT [REV
CURRENT](-C)
Motor
output
MOTOR OUTPUT [NO CURRENT(-d)
MOTOR OUTPUT
[OVERCURRENTI(-e)
CODE
54 - - VEHICLE SPEED SEN [NO SIGNAL21
Vehicle
speed signal VEHICLE
SPEED SEN [NO
SIGNAL31
VEHICLE SPEED SEN [SIGNAL
TURNJ(.b)
VEHICLE SPEED SEN [RPD SIG
CHG21
STEERING ANGLE SEN [NO ANG
SIG](.a)
Steering
angle signal
STEERING ANGLE SEN [ANG SIG FIXJ(.~)
STEERING ANGLE SEN [ANG
FIX30°](-g)
- - -- -- - - STEERING ANGLE SEN [NO NEUT
SIG](-b)
STEERING ANGLE SEN [NEUT SIG
OFFI(4
cg Steering
angle neutral
signal STEERING ANGLE
SEN [NEUT
SIG
ONI(.d)
STEERING ANGLE SEN [OFFSET
NEUTJ(-f)
RR ST ANGLE SENSOR [MAIN
SIGNAL](-a)
Rear
steer-
ing angle
main sensor
signal
- RR ST ANGLE SENSOR [ABNORML
VOL](.d)
RR
ST ANGLE SENSOR [OFFSET SIG](.c)
Rear steer-
ing angle
su
b-sensor
signal RR
ST ANGLE SENSOR [SUB
SIGNAL](.b)
RR ST ANGLE SENSOR [ABNORML
VOL](.d)
RR ST ANGLE SENSOR [OFFSET
SIGJ(C)
ENG REV SIGNAL [ABNORMAL SIGNAL]
Engine
speed signal

ELECTRIC SUPER HICAS
Symptom Chart (Cont'd)
Diagnostic item
Self-diagnosis CONSULT
-
Mal-
f unc-
tion
code No.
Cannot enter self-diagnosis mode. Diagnostic item
HICAS warning lamp is not tumed ON by switching the ignition
3N.
IICAS warning lamp is turned ON by switching the ignition ON but
s not turned OFF by starting the engine.
llumination of HICAS warning lamp has occurred after engine
;tarted. Diagnostic
item
Steering effort does not change with vehicle speed.
rhere is an abnormal noise.
Self-diagnosis with CONSULT displays
"CODE54".