1998 NISSAN GT-R engine oil

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
Clutch and Band Chart
U0.C
(Low one-
way
clutchl L&R/B
(Low and
reverse
brake)
F/O C
(Forward
clutch)
.
Remarks
PARK POSI-
TION
REVERSE POSITION
O/C
(Overrun
clutch)
*I@
'I@
'18
@
NEUTRAL
POSITION
*"
c'utch)
0
0
WC
clutch)
(Reverse
0
P
R
N
Automatic shift
0
0
FIC
(For-
ward
clutch)
0
0
0
69
0
Band servo
'4
2 Automatic shift
1 st
2nd
-3rd 4th
1 st
1. Locked in 1st
-
4th apply
0
2nd apply
0
'263
*3@
2nd
I st
2nd
0
0
0
DUAL MATIC M-ATx
3rd release
0
8
0
0
0
--
fi In Band servo I FI0.C / UOC I L&WB I
(Reverse clutch) FIC (For- WC (High
ward
clutch) clutch)
PARK POSI-
TION
REVERSE POSITION
NEUTRAL POSITION
@ 0 . . Automatic shift
0 '269 8 - -
-38 8 0
@
G3 0 Automatic shift
10 I I Automatic shift
I I I I I I I
:ch is being set in "OFF position. (D, shift is inhibited.) '2: oil pressure is applied to both 2nd "apply" side and 3rd "releasen side of band servo piston. However, brake band does not contract because oil pressure area on the "releasen side is greater than that on the "apply" side. '3: Oil pressure is applied to 4th "apply" side in condition '2 above, and brake band contracts. '4: A/T will not shift to 4th when overdrive control switch is set in "OFF position.
* 1 : O~erate when control
swil
0: Operates. a: Operates
during "progressive" acceleration.
@: Operates but does not affect power transmission. @: Operates when throttle opening is less than specification, but does not affect engine brake. fi: O~erates when throttle opening is less than specification, activating engine brake.

TROUBLE DIAGNOSES
n t
\-Test port for "D", "2", and "1" positions
I 'Test port for "I?" position I
Line pressure specification
Basic Inspection
Arr FLUlD
Check A/T fluid for leakage and fluid level.
Check A/T fluid status.
SHIFT CONTROL
Check and adjust A/T position.
Line Pressure 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 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. After warming up IW', remove fluid pressure detection plug,
and install pressure gauge (Special Service Tool:
ST2505
S001) to corresponding line pressure port.
CAUTION:
0 To remove or install the fluid pressure detection plug, use
standard socket wrench (width across flat:
12 mm).
Detection plug should not be reused because thread-lock
compound is applied
to the plug.
4. Set parking brake and block wheels.
5. Start engine and measure line pressure at idle and stall speed.
CAUTION:
When measuring line pressure, depress brake pedal fully.
When measuring line pressure at stall speed, refer to
"Stall Test" (AT-17).
I p- Line pressure MPa (kg/crn2)
Engine speed
I "RW position "On, 'Z", "1" positions (4AT)
"Dm,
"3", "2" positions (M-AT)
At idle speed
At stall speed 0.58 - 0.62 (5.9 - 6.3) 0.47 - 0.51 (4.8 - 5.2)
1.71
- 1.78 (1 7.4 - 18.2) 1.22 - 1.29 (1 2.4 - 13.2)

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
Symptom Chart
Sharp shock in Engine brake
applied
Shifting
Malfunctions
Slip
(Racing)
hifting
.- erator pedal
Shifting
Shifting
inspection item
Fluid level and status
Control linkage
PNP switch (short/open circuit)
Throttle ~osition sensor (installed)
I Vehicle weed sensor
I Enaine meed sensor
A/T fluid temperature sensor
Engine idle speed
Line
Dressure
Control valve assembly
Shift solenoid
A
Shift solenoid B
Line pressure solenoid
Lock-up solenoid
Overrun clutch solenoid
Accumulator N-D
Accumulator
1-2
Accumulator 2-3
Accumulator 3-4 (N-R) Ignition coil and starter motor
Overdrive control switch
I AfT mode switch (AUTO)
Torque converter
1 Oil pump
I Reverse clutch
I High clutch
I Forward clutch
I Forward one-wav clutch
I Overrun ciutch
1 Low one-wav clutch
I Low reverse brake
Brake. band (including servo)
Parking linkage

Symptom Chart (Cont'd)
Greater noise
Malfunctions
Inspection item No shifting
I Shifting I
Fluid level
and status 11
Control linkage
-
(I) C 0 .- c. .- (I) 0 a
v
-CU
n - 1
PNP switch
(shortlopen
circuit)
Throttle position sensor (installed)
2 2
Vehicle speed sensor
I Engine speed sensor -
-T
L o 1 Control valve assembly .- - -- Shift solenoid A 4 3
. ' Shift solenoid 6 4 cut I1
--, Line pressure solenoid .- 5 -t Lock-up solenoid ?
6 Overrun clutch solenoid 3
Accumulator N-D
1 Accumulator 1-2 I 1-
Accumulator 2-3
Accumulator 3-4 (N-R)
Ignition coil and starter motor
I Overdrive control switch I 1-
A/T mode switch (AUTO)
A/T mode switch (POWER) I - I Ail mode switch (SNOW) I
I Torque converter I I
1 Oil pump I I -- - - Reverse clutch 0 -
'g High clutch a 4 6
%I Forward clutch I I - .- a Forward one-way clutch -
$ Overrun clutch a, 8
Low one-way clutch
O Low reverse brake 7
Brake band (including servo) 7
Parking linkage

TROUBLE DIAGNOSES
Symptom Chart (Cont'd)
xi - - ([I C V) a, C .- cn C W
t 0 .- .L 2 a, - 8 0 ([I L 0 0 Q
& 0 a, a, Q V)
5 E .- X
i! L a
zl -I - 1 -
- 2 -
-
-
-
-
-
5 - 3 - 4 -
-
-
-
-
-
-
-
-
-
-
-
-
I1 - 0 - 6 - 7 -
-
-
-
-
9 - 8 -
-
vj c 0 .- - .- V) 0 n
Q 7J C ([I
t C .- r ([I c. V) c. 0 C V) a 0 7J 0, C .- 0 C W -
- 2 - 3 -
-
- -
-
1 -
-
-
-
- - a +- ([I a a, 2 0 c. 0 C V) a, 0 u a, - 0 2
8 - 1 -
-
-
-
-
-
-
-
2 - 3 -
-
-
-
-
-
-
-
-
-
-
- I
i
g
- 4 -
-
-
-
-
-
-
B- ; 2 to a =? - 0,
2 5.j c 2.z 2 a0 - 0- z & 5 0 gE V) V)o C 02 .s nu 5 ng %-([I C O c --t .- V) a V) r aa ([I z gz a, a- c 50 -6 s
6 $2
11
2
I
I
Malfunctions
Inspection item
I I I Fluid level and status I I Control linkage 2
PNP switch (shortfopen circuit) 1 I I I Throttle position sensor (installed) 111213
Vehicle speed sensor
214
Engine speed sensor L -
AIT fluid temperature sensor
Engine idle weed
Line pressure
Control valve assembly
Shift solenoid A 3
3
Shift solenoid B 4 4
Line pressure solenoid
Lock-up solenoid
Overrun clutch solenoid
u I I I -
Accumulator N-D I I 1 I Accumulator 1-2
Accumulator 2-3 I Accumulator 3-4 (N-R)
Ignition coil and starter motor
Overdrive control switch
Torque converter
tg Reverse clutch .- High clutch
2 Forward clutch C .- a Forward one-way clutch -.
$ Overrun clutch 0, 8
? Low one-way clutch 3= O Low reverse brake 9
Brake band (including servo)
Parking linkage