1998 NISSAN GT-R display

TROUBLE DIAGNOSES
P ECM (aTCM) InputDutput Signal Reference
Value
SIGNAL VOLTAGES MEASURED WITH OSCILLOSCOPE AND CIRCUIT TESTER
- Signal voltages measured at ECM (-TCM) terminals (terminals for engine control) with a circuit tester and
example of waveforms displayed on an oscilloscope are shown below.
For signal terminals for A/T control, refer to "AIT Trouble Diagnosis" in AT section.
Measured data are affected by many factors such as irregularity of parts, vehicle history, operating
conditions, environment, service status, and measuring instruments and methods.
Terminal
No.
RX / TX
Signal name
I nition signal 8 ower transistor
drive signal)
CH~~"N
ECM & IGN coil
relay control signal (Data
link connector for CONSULT)
Tachometer drive
signal
NOTE: Above
At idle
When cranking: Approx. 0.1 2V
At idle: Approx. 0.1 V
?pprox. 1V
,During approx. 1.5
sec. after ignition switch turned OFF: 4pprox. 1 V 1.5 sec. after ignition switch turned OFF: Battery voltage)
:RB20DE
(UB),
RB25DEJ
Approx.
1.2V
:RB25DET]
Approx.
7.2V At
approx. 2,000 rpm
Approx. 0.15
- 0.25V
Approx. 3V
voltages are measured values obtained by analog circuit tester.
EC-39

TROUBLE DIAGNOSES
DESCRIPTION
CONSULT indicates operation timing of each solenoid such as electrical shift timing and lock-up timing.
Therefore, when there is a definite difference between shift timing detected from shift shock (or engine
speed variation) and the one indicated by CONSULT, mechanical parts other than solenoids and sensors
(including hydraulic circuit) may be malfunctioning. In this case, check the mechanical parts using appli-
cable diagnostic procedures.
Shift schedule (which implies gear position) displayed on CONSULT and that indicated in Service Manual
may differ slightly. This occurs because of the following reasons:
Actual shift schedule has more or less tolerance or allowance.
Shift schedule indicated in Service Manual refers to the point where shifts start, and gear position dis-
played on CONSULT indicates the point where shifts are completed.
Shift solenoid valve A or B (ON/OFF) is displayed on CONSULT at the start of shifting. Gear position
is displayed upon completion of shifting (which is computed by TCM).
To make sure the part No. of ECM-TCM on CONSULT, touch "ENGINE" to verify "C/U PART NUMBER".
SELF-DIAGNOSIS PROCEDURE
Refer to "CONSULT Instruction Manual - Supplement" in details.
1. Turn ignition switch OFF.
2. Connect CONSULT connector to data link connector.
3. Start engine.
4. Touch "START', "NT and "SELF-DIAG RESULTS" sequen-
tially on CONSULT screen.
5. Self-diagnosis results are displayed on the screen.

TROUBLE DIAGNOSES
CONSULT (Cont'd)
SELF-DIAGNOSTIC RESULTS MODE
Diagnostic item 1 Diagnostic item is detected when ... Inspection item - -- -
I TCM does not receive vehicle speed sensor 1 signal due to
open circuit, etc.
TCM receives improper signal during driving. After ignition switch is turned ON, vehicle speed sensor 2 receives improper signal until vehicle starts to run.
VHCL
SPEED
SEN.A/T Vehicle
speed sensor 1 circuit
TCM does not receive vehicle speed sensor 2 signal due to
open circuit, etc.
TCM receives improper signal during driving.
VHCL
SPEED
SEN.MTR Vehicle
speed sensor 2 circuit
TCM detects
folfowing conditions during driving (Except N and
P positions). 0 Excessively high throttle position sensor signal voltage Excessive1 low throttle position sensor signal voltage with idle
switch OF; or full switch ON
THROTTLE
POSl
SEN
Throttle position sensor circuit
SHIFT SOLENOIDN A
SHIFT SOLENOIDN B Shift
solenoid A circuit
Shift solenoid
B circuit
Overrun clutch solenoid circuit
TIC
CLUTCH SOW
I
OVERRUN CLUTCH SN
Lock-up solenoid circuit Specified voltage is not applied to solenoid due to open and/or
short circuit.
LINE
PRESSURE SN
I Line pressure solenoid circuit
0 Excessively low supply voltage to TCM during driving
Excessively high si nal voltage of AIT fluid temperature sensor
(excessively low d fluid temperature) during driving This message is displayed only when malfunction occurs with ignition switch ON, and does not have memory func-
tion.
fluid temperature sensor circuit,
TCM power supply circuit, or
throttle position sensor power sup-
ply circuit
BATT/FLUID
TEMP SEN
ENGINE SPEED SIG
I Excessively low engine speed during driving Engine speed
signal circuit
Turbine sensor circuit
TURBINE
SENSOR
(Except
RB20DE)
SHIFT SOLENOIDN C
(Except
RB20DE)
TCM does not receive input shaft speed sensor signal due to
open circuit,
etc.
0 TCM receives improper signal during driving.
0 TCM does not receive shift solenoid A pressure detection switch
signal due to open
andfor short circuit. Shift solenoid A pressure
detection
switch circuit
MANUAL MODE SW
(Except
RB20DE)
TCM does not receive proper manual mode switch signal due to
open and/or short circuit. Manual
mode switch circuit
ENGINE BRAKE
C/U'1
(Except
RB20DE)
Shift control unit does not operate properly due to open and/or
short circuit of each
input/output signal wire.
Malfunction occurs in shift control unit. Each
signal wire circuit connected
to shift control unit
'INITIAL START*
Power supply to TCM is shut down, and self-diagnostic memory
function is canceled due to battery removal, etc.
CONTROL UNIT (RAM)
I Malfunction is detected in TCM memory (RAM) function.
CONTROL
UNIT
(ROM)
I Malfunction is detected in TCM memory (ROM) function.
'1 : Indicates shift control unit.
DATA MONITOR PROCEDURE
Refer to "CONSULT Instruction Manual - Supplement" and "CON-
SULT Service Manual
- Supplement" in details.
1. Turn ignition switch OFF.
2. Connect CONSULT connector to data link connector.
3. Turn ignition switch ON.
4. Touch "START', ''AT and "DATA MONITOR" sequentially on
CONSULT screen.

TROUBLE DIAGNOSES
CONSULT (Cont'd)
DATA MONITOR MODE (M)
1 I Monitor item
I
tem Display ECU
input Main
signals
-
Description Remarks
signals
VHCUS
SE.A'T
[kmlh] or [mph]
I-
Vehicle speed computed from When
racing engine in "Nn or "P" signal of revolution sensor is position
with vehicle stationary,
displayed. CONSULT
data may not indicate
0 kmlh (0 mph).
Vehicle speed computed from Vehicle
speed display may not be
signal of vehicle speed sensor accurate under approx. 10 kmlh
is displayed. (6 mph). It may not indicate 0
kmlh (0 mph) when vehicle is sta-
tionary.
Throttle position sensor signal
voltage is displayed.
AlT fluid temperature sensor
signal voltage is displayed.
Signal voltage lowers as fluid
temperature rises.
Source voltage of TCM is dis-
played.
Engine speed, computed from Engine speed display
may not be
engine speed signal, is
dis- accurate under approx. 800 rpm.
played. It
may not indicate
0 rpm even
when engine is not running.
Turbine revolution computed Error
may occur under approx.
from signal of turbine revolution 800 rpm and will not indicate
0
sensor is displayed. rpm even if engine is not running.
ONIOFF state computed from
signal of overdrive control SW
is displayed.
ONIOFF state computed from
signal of PIN position SW is
displayed.
ONIOFF state computed from
signal of
R position SW is dis-
played.
ONIOFF state computed from
signal of D position SW is dis-
played.
ONIOFF status, computed from
signal of 2 position SW, is dis-
played.
signal of
1 position SW, is dis-
displayed. ASCD is mounted.
ON
... Cruising state
OFF ... Normal running state
Vehicle
speed sensor
1 (All) (Revolution sensor)
Vehicle speed sensor
2 (Meter) VHCUS SE,MTR
[kmk] or
[rnph]
Throttle position sensor
ITHRTLPOS SEN
I ,
AT fluid temperature sensor
PI
FLUID TEMP SE
Battery voltage
A
Engine speed ENGINE SPEED
[rpml
Turbine revolution sensor
TURBINE REV
[rpml
I
Overdrive control switch
OVERDRIVE SW
[ONIOFFJ
I
PIN position switch
PIN POSI SW
[ONlOFF]
R position switch
R POSITION SW
[OWOFF]
I
2 position switch
1
2 POSITION SW
[ONIOFF]
I
D position switch
1 position switch 1 POSITION SW
[ONIOFF]
I
D POSITION SW
[ON/OFF] X
ASCD OD cut signal
ASCD.OD CUT
[ONIOFF]
X
ASCD cruise signal
Status of ASCD OD release
signal is displayed.
ON
... OD released
OFF ... OD not released
ONIOFF status, computed from
signal of
kickdown SW, is dis-
played.
ONIOFF status, computed from
signal of HOLD shift SW, is dis-
played.
ONIOFF status, computed from
signal of closed throttle position
SW, is displayed.
ONIOFF status, computed from
signal of wide open throttle
position SW, is displayed.
ASCD.CRUISE
[ONIOFF]
This
is displayed even when no
ASCD is mounted.
This is displayed even when no
kickdown switch is equipped.
Kickdown
switch
KICKDOWN
SW
[ONIOFq
Wide open throttle position switch X .
X A/T mode switch
t
WIO THRUP-SW
[ONIOFq POWERSHIFT SW
[ONIOFF]
Closed
throttle position switch
, CLOSED THUSW
[ONIOFF]

TROUBLE
CONSU (Cont'd)
I Monitor item
Display input
signals Main
signals
-
Description Remarks
Indicates check signal (reen-
trant signal) status for TCM
control signal output.
ONIOFF
status of shift solenoid is not
changed when thermal insula-
tion or short-circuit occurs in
these valves.
Shift solenoid A SHlFT
SN A
Shift solenoid
B [ONIOFF]
OVRRUNIC SN
- [ONOFF]
Overrun
clutch solenoid
OVRRUN/C SN2
- [ONIOFF]
HOLD SW
[ONIOFFI
X
MANU MODE SW
[ONIOFFJ
NONM MODESW
[ONIOFF]
UP SW
[ONOFF]
X
DOWN SW
[ON/OFFl X
NON SHlFT SW - [ONlOFF]
Overrun
clutch solenoid
2 (Excep
RB20DE)
HOLD!SNOW
switch
A/T mode switch - SNOW mode
1 Gate side contact in mznual
mode switch
Manual
mode switch (Except
RB20DE)
- Non-gate side contact in
manual mode switch
UP (+) side contact in manual
mode switch
Non-manual
mode switch (Excepi
RB20DE)
UP switch (Except
RB20DE)
DOWN (-) side contact in
manual mode switch
DOWN
switch (Except
RB20DE)
Non-shift switch (Except
RB20DE)
Brake switch
I Stop lamp switch
BRAKE SW
[OWOFF] I
Shift solenoid A pressure detec-
tion switch
Gear position data used for
computation by TCM, is dis-
played.
Selector lever position data, A specific value used for control
used for computation by TCM, is
displayed if fail-safe is
acti-
is displayed. vated
due to error.
Vehicle speed data, used for
computation by TCM, is dis-
played.
- -- Shift solenoid valve A (P switch)
(Except
RB20DE) SHlFT
SN A
Gear position
- --- - - Selector lever position SLCT
LVR POSl
I -
VEHICLE
SPEED
[kmlh] or [mph]
I -
Vehicle speed
THROTTLE POSl
Throttle position data, used for A specific value used for control
computation by TCM, is
dis- is displayed if fail-safe is acti-
played. vated due to error.
Throttle
position
- - Control value of line pressure
solenoid valve, computed by
TCM from each input signal, is
displayed.
Control value of torque con-
verter clutch solenoid valve,
computed by TCM from each
input signal, is displayed.
Line
pressure duty LINE
PRES
DTY I
-- Torque converter clutch soienoid
valve duty TCC
SN DUTY I
Shift solenoid valve A .-control value of shift solenoid Control value
of solenoid is dis-
valve A, computed by TCM played even
if solenoid circuit is
from each input signal, is
dis- disconnected.
. - played. The
"OFF signal is displayed if
Control value of shift solenoid solenoid circuit is shorted.
Shift solenoid valve El SHIFT SN B I valve 6, computed by TCM
from each input signal, is dis-
played.
Control value of overrun clutch
solenoid valve computed by
TCM from each input signal is I OVERRUNIC SN I Overrun clutch solenoid valve
displayed.
D Control status of TCM power
>OWER
SFT
LMP
Power shift lamp
shift lamp
-- - Voltage
- Pulse
X: Applicable
-: Not applicable

TROUBLE DIAGNOSES
Self-diagnosis
DESCRIPTION
If malfunction should occur in electrical systems, turning ignition switch ON lights M mode switch POWER
indicator lamp
(M-AT Dual matic AfT warning lamp) for 2 seconds, and then flashes the indicator lamp for 8 Gc
seconds. If malfunction does not occur, A/T mode switch POWER indicator lamp (M-AT Dual matic A/T warn-
ing lamp) is turned on for
2 seconds upon turning ignition switch ON. To locate and display the malfunction-
ing part, output the trouble information memory and flash
A/T mode switch POWER indicator lamp (M-AT Dual
matic
A/T warning lamp) by inputting self-diagnostic startup signal.
SELF-DIAGNOSIS PROCEDURE
1. Warm up engine.
2. Repeat ON-OFF cycles of ignition switch for more than once, and turn it OFF at last.
3. Move A/T mode switch to AUTO, and turn overdrive control switch to O/D ON.
4. Turn ignition switch ON with selector lever in "Pn position, and ensure POWER indicator lamp is turned on
for
2 seconds.
5. Turn ignition switch OFF.
6. Move selector lever to "D" position.
7. Turn overdrive control switch O/D OFF.
8. Turn ignition switch ON.
9. Move selector lever to "2" position.
10. Turn overdrive control switch OID ON.
11. Move selector lever to "I" position.
12. Turn overdrive control switch O/D OFF.
13. Depress accelerator pedal fully, and release it.
14. Read flashing status of POWER indicator lamp to complete self-diagnosis procedures.
M-AT
1. Warm up engine.
2. Repeat ON-OFF cycles of ignition switch for more than once, and turn it OFF at last.
3. Turn ignition switch ON with selector lever in "P" position, and ensure dual matic PJT warning lamp is turned
on for
2 seconds.
4. Turn ignition switch OFF.
5. Depress brake pedal, release accelerator pedal, and then move selector lever to "D" position.
6. Turn ignition switch ON.
7. Release brake pedal, and move selector lever to "3" position.
8. While depressing brake pedal with left foot, depress accelerator pedal fully with right foot, and move
selector lever to
"2" position.
9. Read dual matic A/T warning lamp indication to complete self-diagnosis procedures.

ANTI-LOCK BRAKE SYSTEM
Control Unit InputfOutput Signal Specifications
(Cont'd)
USING CONSULT
Indicated are the control unit computed data. If the output circuit (harness) should be open or short-
circuited, correct values may be displayed.
Check item (Reference)
Data monitor
Display Condition
Monitor
item
Specifications
Vehicle is stationary.
I 0 kdh
FR RH SENSOR
FR LH SENSOR
RR SENSOR
[kdh]
Virtually the same speed
as speedometer (within
+I 0%)
Wheel sensor and circuit
Wheel speed
Vehicle is
drivem'l
Brake pedal is
depressed. Stop lamp switch and
circuit
STOP
LAMP SW
[ON-OFF] Brake pedal status
Brake pedal is not
depressed. OFF
-- --
Actuator (solenoid)
is
activated (at CONSULT
active test),
or
actuator relay is not
activated (with fail-safe
function activated and
engine not running).
FR
RH IN SOL
FR
LH IN SOL
REAR IN SOL
[ON-OFF]
ABS solenoid and circuit
Solenoid status
FR RH OUT SOL
FR
LH OUT SOL
REAR OUT SOL
[ON-OFF]
-- -- - -- -
Actuator (solenoid) is not
activated and actuator
relay is activated (with
vehicle stopped and
engine running).
Actuator relay is acti-
vated (with engine run-
ning).
Actuator relay is not acti-
vated (with fail-safe
function activated and
engine not running).
ABS actuator relay and
circuit
OFF
ON
OFF
ACTUATOR
RLY
[ON-OFF] Actuator
relay status
Motor relay and motor
are activated (at CON-
SULT active test). ABS
motor, motor relay,
and circuit
MOTOR
RLY
[ON-OFF] Motor
relay and motor
status Motor relay and motor
are not activated. OFF
ABS warning lamp and
circuit
- -
Waming lamp ON'2 1 ON
WARNING LAMP
[ON-OFF] ABS
warning lamp sta-
tus
Power supply voltage
provided for control unit -- -
Warning lamp OFF'2 1 OFF
Control unit power sup-
ply circuit - -
BAlTERY VOLT [V] Ignition switch
ON
'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: One second after the ignition switch is turned ON (with the system in normal condition)

ANTI-LOCK BRAKE SYSTEM
CONSULT
CONTROL UNIT PART NUMBER
The part number that is shown on the control unit label and CON-
SULT 47850 AAOOO
- SELF-DIAGNOSIS PROCEDURE
Coliect information on the concern from the customer, and then
perform basic inspections.
Turn ignition switch
OFF and connect CONSULT connector to
data link connector for CONSULT on the vehicle.
Start engine and drive vehicle at approx.
30 km/b for approx.
1 minute.
Stop vehicle and touch "START",
"ABS" and "SELF-DIAG
RESULTS" sequentially on the CONSULT screen with engine
running.
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 self-diagnosis procedure from the beginning.
Self-diagnosis results are displayed on the screen. (Touch
"PRINT" to print out the self-diagnosis results, if necessary.)
If
"NO FAIL" is displayed, inspect ABS warning lamp. Refer to
the previous page.
Perform appropriate inspection from the self-diagnostic results
mode and repair or replace faulty parts.
Start engine and drive vehicle at approx. 30
km/b for approx.
1 minute.
Recheck to ensure that there is no other malfunction.
Turn ignition switch OFF to prepare for erasing the trouble
stored in memory.
Start engine and touch "START",
"ABS", "SELF-DIAG
RESULTS" and "ERASE" sequentially on the CONSULT
screen to erase the trouble stored in memory.
If the trouble stored in memory is not erased, repeat step
6.
10. Drive vehicle at approx. 30 km/h for approx. 1 minute and then
confirm that ABS warning lamp is
off.