sensor NISSAN GT-R 1998 Owner's Guide

TROUBLE DIAGNOSES
System Description
Vehicle with RB20DE and RB25DET engine has TCM integrated into ECM. Vehicle with RB25DE engine has
TCM and ECM separately.
Fail-safe Function @ When malfunction occurs in each sensor and solenoid, the fail-safe functions below enable vehicle to be
driven.
VEHICLE SPEED SENSOR 1 (Output shaft speed sensor)
Inputs a signal from vehicle speed sensor in speedometer. EG
THROTTLE POSITION SENSOR
Detects throttle opening by idle switch and full switch, and controls line pressure as follows. I 1 I Idle switch
-
--
I
--
ON OFF I Minimum oil pressure I 0/8 ST
I
OFF OFF
Full switch
ON Maximum oil pressure
PNP SWITCH
When the multiple PNP switch signals are input to TCM and ECM-TCM, the priority of selector lever position I28
becomes as follows by internal TCM determination.
4AT D, N, R, 2, 1 I%$ M-AT D, N, R, 3, 2
Because the hydraulic circuit of the control valve is switched by manual valve according to the selector lever
position, however, actual operating condition of vehicle becomes as follows.
EL
I N I "N" and other position signals I N
Line pressure
218
P
R
- - -- pp - pp - -
4AT I D I "D" and other position signals I Dl*DP*Dd
Throttle opening I
418 BR
Running status
Actual lever position
1 "2 and other position signals I 21 ~22
PNP switch input signal
"P and other position signals
"R" and other position signals
--
r"2 and "1" 21 ~22
P 83
R
I 2 1 "2" and other position signals / 21 42
M -AT
3
L
1
P
R
N
D
"1" and other position signals
"P" and other position signals
"R" and other position signals
"N" and other position signals
"D" and other position signals
I
l,++l2
P
R
N
D1t;.D2c*D3
"3 and other position signals
"3" and "2" position signals
3, -3,-3-3,
3, +3, +3,

TROUBLE DIAGNOSES
Fail-safe Function (Cont'd)
SHIFT SOLENOID A, B
When a malfunctioning signal of solenoid is input to TCM and ECM-TCM, the gear is shifted as follows.
Normal Abnormal solenoid A Abnormal solenoid B Abnormal solenoid A/B Shift positions A B Gears A B Gears A I3 Gears A 8 Gears
0 0 1 st o-+x 03x - - - -
-- 0: Solenoid ON X: Solenoid OFF -: Abnormal
LINE PRESSURE SOLENOID
When a malfunctioning signal of solenoid is input to TCM and ECM-TCM, the line pressure solenoid is turned
OFF, and the line pressure is set to maximum oil pressure.
LOCK-UP SOLENOID
When a malfunctioning signal of solenoid is input to TCM and ECM.TCM, the lock-up solenoid is turned OFF,
and the lock-up
is released.
OVERRUN CLUTCH SOLENOID
When a malfunctioning signal of solenoid is input to TCM and ECM-TCM, the overrun clutch solenoid is turned
OFF, and the overrun clutch is engaged to apply the engine brake during deceleration.
MANUAL MODE SWITCH (M-AT)
When a malfunctioning signal of manual mode switch is input to TCM and ECM.TCM, the gear is controlled
with normal "D" position.
SHIFT CONTROL UNIT (Except RB20DE)
When a malfunction occurs in the shift control unit, the shift solenoid NB are turned OFF, and the gear posi-
tion
is controlled with 3rd speed.
TURBINE SENSOR (Except RB20DE)
Controlled by vehicle speed sensor 1 in the same way without turbine sensor

TROUBLE DIAGNOSES
Shift Mechanism
1 Turbine sensor 1
tine pressure solenoid I 1
Shift solenoid B
Full switch
ECM-TCM
(All side) (RB20DE, RB25DET) or TCM (RB25DE) p-
ECM.TCM (Engine side) * I
(RB20DE. RB25DET) or Venrle speed sensor 2
ECM (RB25DE) ,
1 (RB25DET)
POWER ~nd~calor lamp @AT;
( POWER (Except M-AT) ] 1 SNOW I
Shift control unit
(Except RB20DE)
Overdrive control switch
I
O/D OFF
indicator lamp
Steering shift main switch
- ATN 1983D

TROUBLE DIAGNOSES
Circuit Diagram
1 Data link connector for CONSULT
I I Vehicle speed sensor 1 I I (Output shaft speed sensor)
Turbine sensor (Exceot RB20DE)
Shifi CRI (M-AT)
65 10 Steering shifl SW (M-AT)
Steering shift main SW
1
Manual mode SW I
Terminal No. in parenthesis ( ) of throttle position sensor and throttle posit~on switch 1s used for RB25DET.
AT-8

TROUBLE DIAGNOSES
Circuit Diagram (Cont'd)
Data link connector for C0NS;ILT
Engine speed signal -
i? Throttle ~otal controi port&-2 s-2 33 7'' ELM I E - , 10
AT mode SW & '' 19
(2WD)
1- 1 I I Throttle msition sensor
I I Vehicle speed sensor 1
Turbine sensor 38 -
Throttle position SW 2 r I- 16
L TO IGN SW I PNPSW
To starter relay 4-1 34 - 27
A i 26
n I IGN IOA ID OFF 1ND.L AT> I T 22 I Shift CIU
ATN 1 987D

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

TROUBLE DIAGNOSES
Line Pressure Test (Cont'd)
JUDGEMENT OF LINE PRESSURE TEST
At idle
speed
At stall
speed Judgement
Line pressure is low in all
positions.
Line pressure is low in par-
ticular position.
Line pressure is
high.
Line pressure increase is
poorer than that measured at
idle speed.
Line pressure increases but
does not reach specification.
Line pressure is low in par-
ticular position. Possible
causes
Pressure supply system malfunction or low oil pump output
Examples:
0 Oil pump wear
Control piston damage
Pressure regulator valve or plug sticking, and weak spring
Fluid pressure leakage between oil strainer and pressure regulator valve through oil Eg
Pump
Low idle speed
After line pressure is supplied from manual valve, fluid pressure may leak between devices
or circuits of corresponding position.
1
Malfunctions of sensors or pressure regulation function. El
Examples:
Misadjustment of throttle position sensor
PJT fluid temperature sensor damaged ST
Poor operation of line pressure solenoid (stuck with OFF status, clogged filter, or open
harness)
Pressure modifier valve sticking F%
Pressure regulator valve or plug sticking
Malfunctions of sensors or pressure regulation function
Examples:
EILA
Misadjustment of throttle position sensor
TCM, ECM.TCM damaged la
Poor operation of line pressure solenoid (stuck or shorted with ON status)
Pressure regulator valve and plug sticking
Pressure modifier valve sticking
sf$
Pilot valve sticking and pilot filter clogged
Malfunctions of pressure supply system, sensors, or pressure regulation function
Examples:
Misadjustment of throttle position sensor
Control piston damage
Poor operation of line pressure solenoid, and filter sticking or clogged
Pressure regulator valve and plug sticking
Pressure modifier valve sticking
Pilot valve sticking and pilot filter clogged
After line pressure is supplied from manual valve, fluid pressure
may leak between devices
or circuits of corresponding position.
Stall Test
1. Check engine oil level. If necessary, add oil.
2. Drive vehicle for approximately 10 minutes until A/T fluid
reaches normal operating temperature between
50 and 80°C,
and check A/T fluid level. If necessary, add AfT fluid.
When ambient temperature is
20°C,
A/T fluid operating tem-
perature usually becomes between 50 and
80°C for approxi-
mately
10 minutes' drive in urban traffic.
3. Set parking brake and block wheels.
4. Statt engine, depress brake pedal, and move selector lever to
"D" position.

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.