1998 NISSAN GT-R battery

TROUBLE DIAGNOSES
ECM (-TCM) InputlOutput Signal Reference
Value (Cont'd)
d
voltages are
Terminal No. Signal name
At idle At
approx. 2,000 rpm
Approx.
12V Approx. 8V
AAC valve control
signal
[RB20DE
(UB), RB25DEl
During 5 sec. after ignition switch tumed ON: Approx. 0.25V 5 sec. after ignition switch turned ON: Battery voltage
When cranking: Approx. 0.25V At idle: Approx. 0.25V Fuel pump relay
control signal - - [RB25DETJ
During 3 sec. after ignition switch tumed ON: Approx.
0.9V
3 sec. after ignition switch tumed ON: Battery voltage
When cranking: Approx. 0.9V At idle: Approx. 0.9V
Approx. 0.9V
Air conditioner
relay control signal Air conditioner
OFF: Battery voltage
Air conditioner ON: Approx. 0.25V
MIL OFF: Battery voltage
MIL ON
RBZODE
(UB), RB25DE: Approx. 0.85V RB25DET Approx. 0.1 V
Malfunction indica-
tor lamp
lgnition switch
(START) signal
Air conditioner
switch signal Approx.
OV (Ignition
switch at START Battery voltage)
Air conditioner OFF: Approx.
4.7V Air conditioner ON: Approx. 0.1 V -
22 (CHK) Check
(Diagnosis
start)
Throttle position
sensor signal
lgnition switch
(IGN) signal CONSULT
connected: Approx. OV CONSULT not connected: Approx. OV
Accelerator pedal released: Approx. OSV Accelerator pedal fully depressed: Approx. 4.2V
(Ignition switch ON, engine not running)
lgnition switch
OFF: Approx. OV lgnition switch ON: Battery voltage Approx.
0.6 - 0.7V
24
(IGN)
Ground Approx.
OV
Power
steering oil
pressure switch
signal Steering
wheel not tumed: Approx. 4.N Steering wheel turned: Approx. OV
26
NOTE: I bove measured values obtained by analog ircuit
tester.

TROUBLE DIAGNOSES
ECM (*TCM) InpuWOutput Signal Reference
Value (Cont'd)
Terminal
No.
41
NOTE: I
Signal name At
idle
rlehicle speed sen-
;or signal
dead lamp switch Light switch OFF: Approx. OV
;ignal
Light switch ON: Battery voltage
gnition power
sup- Ignition switch OFF: Approx. OV
)iY Ignition switch ON: Battery voltage
dle position switch
lB25DET.m
Mottle
opening Accelerator pedal released: Approx.
0.5V
ignal
Accelerator pedal fully depressed: Approx.
4.2V RB25DE.4WD.W
(Ignition switch ON, engine not running) ; RB25D€.AlT,
3R25Dm
Jeutral signal Selector lever in Neutral or in
N or P position: Approx. OV ParWNeutral posi- Selector lever in other positions: Approx. 4.8V
on switch)
:ull switch signal Accelerator pedal released: Approx. OV
?B20DE
(UB), Accelerator pedal fully depressed: Battery voltage
lB25DET-A/Tl (Ignition switch ON, engine not running)
- - - - -- - love voltages are measured values obtained by analog
At approx. 2,000 rpm
IRB20DE
(UB)] When driving at approx. 40 km/h: Approx. 2.4V @I
i ECL 1 7920
[RB25DE, RB25DETI
When driving at approx. 40
kmk: Approx. 2.4V %R
Approx. OV
(When accelerator pedal is depressed)
Approx.
0.N
rcuit tester.

TROUBLE DIAGNOSES
ECM (-TCM) Input/Output Signal Reference
Terminal No. Signal name
At approx. 2,000 rprn At idle
When cranking: Approx.
1.3V
Approx.
1.4V
ECLl426D
Crankshaft position
sensor 120" (REF) sig-
nal At idle: Approx. 1.35 - 1.4V
When cranking: Approx.
2.6V
Approx.
2.6V
Crankshaft position sensor 1" (POS) signal jle: Approx. 2.6V
ECLl428C
When cranking (DC range): Approx. (AC range): Approx.
DC range: Approx.
0.1V
AC range: Approx. 3.2V
Ring gear crankshaft
position sensor signal
[RB20DE
(UB)]
At idle DC range - Approx. 0.1 V [Ac range]. /\ppmx. 1 .W (v: 15 10 5 0
t (When engine raced sirddenly: Approx. 2.7 - 3.1V)
Turbo
Dressure
sensor
signal ' [RB25DET]
Throttle position sensor,
refrigerant pressure
sensor, turbo pressure
sensor power supply
Rear defogger switch
signal
-
49
NOTE: ,
2ear defogger switch OFF: Approx. OV
Rear defogger switch ON: Battery voltage
C-
bove voltages are measured values obtained by analog circuit tester.
EC-42

TROUBLE DIAGNOS
ECM (.TCM) lnpu
:s
3utput Signal Reference
Value (Cont'd)
.. No.
Fluctuates between approx. 0.1 to
0.4V and approx.
0.7 to
0.9V At
idle
- I I - I I -
I
I
- are measured
At approx. 2,000 rpm
:v: i .5 I .O 0.5 0
ECL 1 8645 11jllllllll ECL 1 8630
Throttle motor sensor
signal
[RB25DET'J Approx. 3.4V
I (Voltage becomes lower when TCS operates.)
Motor throttle switch
signal
[RB25DET]
Approx.
4.7V
Mass air flow sensor
signal
t
(When TCS is operating: Approx. OV)
Ignition switch ON: Approx.
0.2V
At idle: Approx.
1
.I - 1.2V Approx.
1.6 - 1.7V
Mass air flow sensor
ground Approx.
OV
I
Coolant temperature approx. 20°C: Approx. 3.5V
Coolant temperature approx.
80°C: Approx. 1.2V
Approx. 0.36V min.
(Voltage increases as the air conditioner refrigerant
pressure increases.)
Approx. 0.4
- 2V (') ': Voltage varies with measuring range (internal resis-
tame) of a circuit tester.
Battery voltage
C
+
+
+
56
-
62 1 Knock sensor signal 1
Engine coolant tem-
perature sensor signal
57
- -- -
63 1 Knock sensor signal 2
Refrigerant pressure
sensor
67 Control unit power
sup-
72
I PIY Receive (Data input to
control unit) 1
Transmit (Data output
from control unit) CONSULT
connected: Approx. 0.25V
CONSULT
not connected: Battery voltage
CONSULT connected: Approx.
9V max. CONSULT not connected: Approx. OV
C
Fan stopped: Battery voltage
Fan operating: Approx. 0.2 - 0.3V 78
NOTE: Above
Auxiliary electric fan
relay control signal
[RB25DE, RB25Dm
voltages values obtained
analog circuit
tester.

TROUBLE DIAGNOSES
ECM (-TCM) Input/Output Signal Reference
Terminal No.
108
- NOTE:
Signal name
CM.TCM, TCS/ABS
tegrated control signal
dultiplex communica-
&DE.m,
B25DETj
attery power supply
ijector drive signal
3attery voltage When cranking: Approx.
10.5V
Value (Cont'd)
(v) 50 40 30 20 10
0
At idle: &Wry voltage
A:
idle
Approx. 2V
rariable
air intake con-
:ol solenoid valve con- switch ON: Battery voltage (Solenoid valve
rot signal
RB20DE (UB), At idle: Approx. 0.2
- 0.3V (Solenoid valve ON) At
approx. 2,000
rpm
t
3B25DEI ' .
-urbo pressure control iO1enOid valve Battery voltage (Solenoid valve OFF)
iianal
4ir jet swirl sole- Coolant temperature below approx. 70°C: Approx.
0.9V (Solenoid valve ON)
'Oid Coolant temperature approx. 70°C and above: Battery
RB20DE (VB)] voltage (Solenold valve OFF)
[RB20DE (UB), RB25DEl
Air conditioner OFF: Battery voltage
Air conditioner ON: Battery voltage Approx.
10V
(After approx.
15 sec.)
Zanister
purge control
~alve
control signal
M 30 20 10 0
(Waveform indicates when air conditioner is
ON.)
[RB20DETJ
Air conditioner OFF: Battery voltage
Air conditioner ON: Battery voltage
4 Approx. 1OV
(After approx. 15 sec.) Slightly lower than battery voltage
t At
approx. 3,650 rpm and above [RB2ODE (UB)]
At approx. 3,500 rpm and above [RB25Dq : Battery voltage (Solenotd valve OFF)
t [When engine raced suddenly: Approx. 0.3V (Solenoid
valve ON)]
t Coolant temperature approx. 70°C and above, and
driving at approx. 3,300 rpm and above [MTT] Coolant temperature approx. 70°C and above, and
driving at approx. 3,000 rpm and above [A/T1 : Approx. 0.9V (Solenoid valve ON)
Approx.
9V
Approx. 9V
I (Waveform indicates when air conditioner is ON.)
tester.

TROUBLE DIAGNOSES
ECM (.TCM) InputlOutput Signal Reference
Value (Cont'd)
I Signal name
No. At
idle 7 At approx. 2,000 rpm
Control unit power sup-
ply (Counter-electromo-
live current feedback
circuit)
Fuel pump terminal
voltage control output
1 signal
IRB25DETI
Variable valve timing ,- control signal Battery voltage
Ignition switch at START: Approx.
OV During approx. 30 sec. after engine started with cool-
ant temperature 50°C or above: Approx. OV At idle: Approx. 1 OV
Battery voltage (Solenoid valve OFF)
Approx.
0.3V
Approx. OV
I t [With driving wheels lifted and gear in D position:
Approx. 0.45V (Solenoid valve ON)] AT
Approx. 0.3V (At approx. 2,800 rpm and above: Battery voltage) 1 I I
NOTE: Above voltages are measured values obtained by analogue circuit tester. BR

TROUBLE DIAGNOSES
Control Unit Input/Output Signal Specifications
Refer to EC section ("ECM.TCM or ECM Input/Output Signal
Reference Value").
USING CONSULT -
Monitor item Indication value Operating status
Throttle position sensor Approx.
0.4 - 4.OV
Throttle fully - closed to fully-open --
AK fluid temperature sensor I Appro~. 1.5 - 0.5V I A/T fluid: Appro~. 20 - 80°C -- - - --- -
ON Overdrive control switch: OFF
Lever switch
OFF Overdrive control switch: ON
Line pressure
duty 29 - 94% Low
pressure - High pressure
Lock-up duty
4 - 94% Lock-up released - Lock-up engaged
USING CIRCUIT TESTER
Terminal
No.' 1 Condition Specifications
.- Refer to EC section
("ECM-TCM or
5 (39) Engine speed signal - ECM Input/Output Signal Reference
Value*).
Voltage increases gradually in
Throttle position sensor
signal After
engine warm-up, depress accelerator pedal
slowly. response
to throttle position.
Fully-closed throttle
: Approx. 0.5V
Fully-open throttle : Approx. 4.2V
24 (I0) Power source
31 (19) Turn
ignition switch ON. Battery
voltage
Turn ignition switch OFF. Approx.
OV
--
25 (25) 1 Ground 32 (48) Turn ignition switch ON. Approx. OV
Shift control
signal SB1 - - 28 (I4) (Except RB20DE)
Vehicle speed sensor
2 When vehicle is moved at 2 to 3 km/h for more than Voltage varies approx. between OV 29 (40) (vehicle speed
signal in 1 m. and 4.5V intermittently.
speedometer)
*: Each number in parenthesis ( ) shows the terminal No. for TCM (RB25DE).

TROUBLE DIAGNOSES
Control Unit
InputlOutput Signal Specifications
Terminal
No.' Operation
or measurement condition Specifications
Idle switch
(in throttle position switch) After
engine warm-up, release accelerator pedal.
After engine warm-up, depress accelerator
pedal.
PNP switch "1"
position
(c > is used for M-AT.) Battery voltage
@ Approx.
OV
PNP switch
"2"
<"33 position
(c > is used for M-AT.) Selector lever:
"1"
&?"2 position
Selector lever;
Exce~t
"1"
<"2"> ~osition Battery voltage
gz
A~~rox.
OV
PNP switch
"Dm position Selector
lever:
2" <3*> position
Selector lever: Except
"Y 4'3'5 position
Selector lever;
"Dn
position Battery voltage
Approx. OV
Battery voltage
Neutral signal
(PNP switch
"N-P"
position)
- -- Selector lever: Except "Dm position Approx.
OV
PNP switch
"Rn
position RR Selector lever: "Nn, "P" position
Selector lever: Except
"N", "Pn position
Selector lever:
"Rn
~osition
I Selector lever: Except "Rn position 1 Approx. OV
U" " Approx. OV
Approx. 4.7V
. Batterv voltaae ST
I
After engine warm-up, depress accelerator pedal
partially. (Throttle opening: More than 50%) Battery voltage i% Full
switch
(in throttle position switch)
I After engine warm-up, release accelerator pedal. I Approx. OV
Sensor ground
Throttle position sensor
power -- -- - - - I
-- --- Turn iqnition switch ON. Ao~rox. OV @z!.
Shift control signal SB2
(Except RB20DE) Turn ignition switch
ON. Turn ignition switch
OFF.
Approx.
4.5 - 5.5V
Approx. OV
EL
Vehicle speed sensor 1
(Output shaft speed sensor) When vehicle
cruises at 30 kwh (Inspected in AC posi-
tion) More
than approx. 1 V
80
(Voltage increases in
resDonse to vehicle
meed.)
Turbine sensor (Except
RB20DE)
When vehicle parks (Inspected in AC position)
When turbine rotates at approx. 1,000
rpm I Approx. 0.1 V
Approx.
OV
rn fluid temperature sensor 5 I A/l fluid temperature: Approx. 20°C Approx. 1.5V
c
3 V) Battery voltage
Approx. OV .- Y .- c a, -
Afr mode switch (POWER)
(Except M-AT)
A/T fluid temperature: Approx. 80°C ,
AIT mode switch: POWER
A/T mode switch: Except POWER - - - - - - -- Shift control signal DB1
(Except RB20DE)
Shift control signal
DB3
(Except RB20DE) Approx. 0.5V
Overdrive control switch
(Except M-AT) Battery voltage
z g 0
Shift
control signal DB2
(Except RB20DE)
A/T mode switch (SNOW)
(Except TCS) Overdrive
control switch: ON (Contact: OFF)
- .= c .- & .&!
- 5
Stop lamp switch Overdrive
control switch:
OFF (Contact: ON)
CONSULT
(RX) signal Approx.
OV
Battery voltage Appro~. OV
Battery voltage
Approx. OV
.z w .- cJ=- T) .g
2
CONSULT (TX) signal
A/l mode switch: SNOW
A/l mode switch: Except SNOW
Depress brake pedal.
' Release brake pedal.
*: Each number in parenthesis ( ) shows the terminal No. for TCM (RB25DE).
AT-1 1