Valve INFINITI FX35 2007 User Guide

AT-32
A/T CONTROL SYSTEM
Revision: 2006 July 2007 FX35/FX45
TCM FunctionNCS001AZ
The function of the TCM is to:

Receive input signals sent from various switches and sensors.

Determine required line pressure, shifting point, lock-up operation, and engine brake operation.

Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transmission senses vehicle operating conditions through various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SENSORS (or SIGNALS)

TCM

ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
Manual mode switch signal
Stop lamp switch signal
Turbine revolution sensor
ATF pressure switch Shift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN system Input clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch
solenoid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Starter relay
Back-up lamp relay
SCIA5325E

AT-34
A/T CONTROL SYSTEM
Revision: 2006 July 2007 FX35/FX45
Line Pressure ControlNCS001B2

When an input torque signal equivalent to the engine drive force is sent from the ECM to the TCM, the
TCM controls the line pressure solenoid.

This line pressure solenoid controls the pressure regulator valve as the signal pressure and adjusts the
pressure of the operating oil discharged from the oil pump to the line pressure most appropriate to the
driving state.
LINE PRESSURE CONTROL IS BASED ON THE TCM LINE PRESSURE CHARACTERISTIC
PATTERN

The TCM has stored in memory a number of patterns for the optimum line pressure characteristic for the
driving state.

In order to obtain the most appropriate line pressure characteristic to meet the current driving state, the
TCM controls the line pressure solenoid current valve and thus controls the line pressure.
Normal Control
Each clutch is adjusted to the necessary pressure to match the
engine drive force.
Back-up Control (Engine Brake)
When the select operation is performed during driving and the trans-
mission is shifted down, the line pressure is set according to the
vehicle speed.
PCIA0007E
PCIA0008E
PCIA0009E

A/T CONTROL SYSTEM AT-37
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Revision: 2006 July 2007 FX35/FX45
Lock-up ControlNCS001B4
The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque converter clutch solenoid valve,
which is controlled by a signal from TCM, and the torque converter clutch control valve engages or releases
the torque converter clutch piston.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
Lock-up Released
In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the torque
converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In this way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-clutched State
The current output from the TCM to the torque converter clutch solenoid is varied to gradually increase the
torque converter clutch solenoid pressure.
In this way, the lock-up apply pressure gradually rises and while the torque converter clutch piston is put into
half-clutched status, the torque converter clutch piston operating pressure is increased and the coupling is
completed smoothly.
Slip Lock-up Control
In the slip region, the torque converter clutch solenoid current is controlled with the TCM to put it into the half-
clutched state. This absorbs the engine torque fluctuation and lock-up operates from low speed.
selector lever D position M5 position M4 position M3 position
Gear position 54543
Lock-up ×–×××
Slip lock-up ××–––
PCIA0014E

AT-38
A/T CONTROL SYSTEM
Revision: 2006 July 2007 FX35/FX45
Engine Brake ControlNCS001B5

The forward one-way clutch transmits the drive force from the engine to the rear wheels. But the reverse
drive from the rear wheels is not transmitted to the engine because the one-way clutch is idling.
Therefore, the low coast brake solenoid is operated to prevent the forward one-way clutch from idling and
the engine brake is operated in the same manner as conventionally.

The operation of the low coast brake solenoid switches the low coast brake switching valve and controls
the coupling and releasing of the low coast brake.
The low coast brake reducing valve controls the low coast brake coupling force.
Control ValveNCS001B6
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
Torque converter regulator valve In order to prevent the pressure supplied to the torque converter from being excessive,
the line pressure is adjusted to the optimum pressure (torque converter operating pres-
sure).
Pressure regulator valve
Pressure regulator plug
Pressure regulator sleeve Adjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valve When the front brake is coupled, adjusts the line pressure to the optimum pressure
(front brake pressure) and supplies it to the front brake. (In 1st, 2nd, 3rd, and 5th gears,
adjusts the clutch pressure.)
Accumulator control valve Adjusts the pressure (accumulator control pressure) acting on the accumulator piston
and low coast reducing valve to the pressure appropriate to the driving state.
Pilot valve A Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for line pressure control, shift change control, and lock-up control.
Pilot valve B Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for shift change control.
Low coast brake switching valve During engine braking, supplies the line pressure to the low coast brake reducing valve.
Low coast brake reducing valve When the low coast brake is coupled, adjusts the line pressure to the optimum pressure
(low coast brake pressure) and supplies it to the low coast brake.
N-R accumulator Produces the stabilizing pressure for when N-R is selected.
Direct clutch piston switching valve Operates in 4th gear and switches the direct clutch coupling capacity.
High and low reverse clutch control valve When the high and low reverse clutch is coupled, adjusts the line pressure to the opti-
mum pressure (high and low reverse clutch pressure) and supplies it to the high and low
reverse clutch. (In 1st, 3rd, 4th and 5th gears, adjusts the clutch pressure.)

A/T CONTROL SYSTEM AT-39
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Revision: 2006 July 2007 FX35/FX45
FUNCTION OF ATF PRESSURE SWITCH
Input clutch control valve When the input clutch is coupled, adjusts the line pressure to the optimum pressure
(input clutch pressure) and supplies it to the input clutch. (In 4th and 5th gears, adjusts
the clutch pressure.)
Direct clutch control valve When the direct clutch is coupled, adjusts the line pressure to the optimum pressure
(direct clutch pressure) and supplies it to the direct clutch. (In 2nd, 3rd, and 4th gears,
adjusts the clutch pressure.)
TCC control valve
TCC control plug
TCC control sleeve Switches the lock-up to operating or released. Also, by performing the lock-up operation
transiently, lock-up smoothly.
Torque converter lubrication valve Operates during lock-up to switch the torque converter, cooling, and lubrication system
oil passage.
Cool bypass valve Allows excess oil to bypass cooler circuit without being fed into it.
Line pressure relief valve Discharges excess oil from line pressure circuit.
N-D accumulator Produces the stabilizing pressure for when N-D is selected.
Manual valve Sends line pressure to each circuit according to the select position. The circuits to which
the line pressure is not sent drain.
Name Function
Name Function
ATF pressure switch 1 (FR/B) Detects any malfunction in the front brake hydraulic pressure. When it detects any mal-
function, it puts the system into fail-safe mode.
ATF pressure switch 2 (LC/B) Detects any malfunction in the low coast brake hydraulic pressure. When it detects any
malfunction, it puts the system into fail-safe mode.
ATF pressure switch 3 (I/C) Detects any malfunction in the input clutch hydraulic pressure. When it detects any mal-
function, it puts the system into fail-safe mode.
ATF pressure switch 5 (D/C) Detects any malfunction in the direct clutch hydraulic pressure. When it detects any mal-
function, it puts the system into fail-safe mode.
ATF pressure switch 6 (HLR/C) Detects any malfunction in the high and low reverse clutch hydraulic pressure. When it
detects any malfunction, it puts the system into fail-safe mode.

AT-40
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2006 July 2007 FX35/FX45
ON BOARD DIAGNOSTIC (OBD) SYSTEMPFP:00028
IntroductionNCS001B7
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp) and is stored as a DTC in
the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the A/T CHECK indicator lamp. The malfunction is
stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail,
refer to AT- 9 2 , "
Display Items List" .
OBD-II Function for A/T SystemNCS001B8
The ECM provides emission-related on board diagnostic (OBD-II) functions for the A/T system. One function
is to receive a signal from the TCM used with OBD-related parts of the A/T system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indicator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in “One or Two Trip Detection Logic” when a malfunction is sensed in rela-
tion to A/T system parts.
One or Two Trip Detection Logic of OBD-IINCS001B9
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — 1st trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd trip
The “Trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)NCS001BA
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( with CONSULT-II or GST) CONSULT-II or GST (Generic Scan Tool) Examples: P0705, P0720 etc.
These DTC are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)

1st trip DTC No. is the same as DTC No.

Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring
or occurred in the past and returned to normal.
CONSULT-II can identify them as shown below, therefore, CONSULT-II (if available) is recom-
mended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown
on the next page. DTC or 1st trip DTC of a malfunction is displayed
in SELF-DIAGNOSTIC RESULTS mode for “ENGINE” with CON-
SULT-II. Time data indicates how many times the vehicle was driven
after the last detection of a DTC.
BCIA0030E

AT-46
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
How to Perform Trouble Diagnosis for Quick and Accurate RepairNCS001BE
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelerator pedal position sensor (throttle position
sensor) or PNP switch and provides shift control or lock-up control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a error that occurs intermittently
rather than continuously. Most intermittent errors are caused by poor
electric connections or improper wiring. In this case, careful check-
ing of suspected circuits may help prevent the replacement of good
parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-II (or GST) or a circuit tester connected should be
performed. Follow the AT- 4 6 , "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “DIAGNOSTIC WORKSHEET” as
shown on the example (Refer to AT- 4 8
) should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
WORK FLOW
A good understanding of the malfunction conditions can make troubleshooting faster and more accurate.
In general, each customer feels differently about a malfunction. It is important to fully understand the symp-
toms or conditions for a customer complaint.
Make good use of the two sheets provided, “Information From Customer” (Refer to AT- 4 7
) and “DIAGNOSTIC
WORKSHEET” (Refer to AT- 4 8
), to perform the best troubleshooting possible.
SAT631IB
SAT632I
SEF234G

TROUBLE DIAGNOSIS AT-49
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Revision: 2006 July 2007 FX35/FX45
4 ❏
Perform all road tests and enter checks in required inspection items. AT- 5 6
4-1. Check before engine is started
AT- 5 7
❏ The A/T CHECK Indicator Lamp does come on. AT- 1 8 9 .
❏ Perform self-diagnostics. Enter checks for detected items. AT- 9 2
, AT- 1 0 2 .
❏ AT-104, "
DTC U1000 CAN COMMUNICATION LINE" .
❏ AT-107, "
DTC P0615 START SIGNAL CIRCUIT" .
❏ AT- 111 , "
DTC P0700 TCM"
❏ AT-112, "DTC P0705 PARK/NEUTRAL POSITION SWITCH" .
❏ AT-116, "
DTC P0717 TURBINE REVOLUTION SENSOR" .
❏ AT-118, "
DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)" .
❏ AT-123, "
DTC P0725 ENGINE SPEED SIGNAL" .
❏ AT-125, "
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE" .
❏ AT-127, "
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)" .
❏ AT-129, "
DTC P0745 LINE PRESSURE SOLENOID VALVE" .
❏ AT-131, "
DTC P1705 THROTTLE POSITION SENSOR" .
❏ AT-134, "
DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT" .
❏ AT-139, "
DTC P1721 VEHICLE SPEED SENSOR MTR" .
❏ AT-141, "
DTC P1730 A/T INTERLOCK" .
❏ AT-144, "
DTC P1731 A/T 1ST ENGINE BRAKING" .
❏ AT-146, "
DTC P1752 INPUT CLUTCH SOLENOID VALVE" .
❏ AT-148, "
DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION" .
❏ AT-150, "
DTC P1757 FRONT BRAKE SOLENOID VALVE" .
❏ AT-152, "
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION" .
❏ AT-154, "
DTC P1762 DIRECT CLUTCH SOLENOID VALVE" .
❏ AT-156, "
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION" .
❏ AT-158, "
DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE" .
❏ AT-160, "
DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION" .
❏ AT-162, "
DTC P1772 LOW COAST BRAKE SOLENOID VALVE" .
❏ AT-164, "
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION" .
❏ AT-166, "
DTC P1815 MANUAL MODE SWITCH" .
❏ AT-171, "
DTC P1841 ATF PRESSURE SWITCH 1" .
❏ AT-173, "
DTC P1843 ATF PRESSURE SWITCH 3" .
❏ AT-175, "
DTC P1845 ATF PRESSURE SWITCH 5" .
❏ AT-177, "
DTC P1846 ATF PRESSURE SWITCH 6" .
4-2. Check at Idle
AT- 5 7
❏ AT- 1 9 0 , "Engine Cannot Be Started in “P” or “N” Position" .
❏ AT- 1 9 1 , "
In “P” Position, Vehicle Moves When Pushed"
❏ AT- 1 9 2 , "In “N” Position, Vehicle Moves" .
❏ AT- 1 9 3 , "
Large Shock (“N” to “D” Position)" .
❏ AT- 1 9 6 , "
Vehicle Does Not Creep Backward in “R” Position" .
❏ AT- 1 9 9 , "
Vehicle Does Not Creep Forward in “D” Position" .
4-3. Cruise Test
AT- 5 8
Part 1
❏ AT- 2 0 1 , "
Vehicle Cannot Be Started From D1" .
❏ AT- 2 0 4 , "
A/T Does Not Shift: D1 → D2" .
❏ AT- 2 0 6 , "
A/T Does Not Shift: D2 → D3" .
❏ AT- 2 0 8 , "
A/T Does Not Shift: D3 → D4" .
❏ AT- 2 11 , "
A/T Does Not Shift: D4 → D5" .
❏ AT- 2 1 3 , "
A/T Does Not Lock-up"
❏ AT- 2 1 5 , "A/T Does Not Hold Lock-up Condition" .
❏ AT- 2 1 7 , "
Lock-up Is Not Released" .
❏ AT- 2 1 7 , "
Engine Speed Does Not Return to Idle" .

AT-50
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
44-3. Part 2
AT- 6 0
❏ AT-201, "Vehicle Cannot Be Started From D1" .
❏ AT-204, "
A/T Does Not Shift: D1 → D2" .
❏ AT-206, "
A/T Does Not Shift: D2 → D3" .
❏ AT-208, "
A/T Does Not Shift: D3 → D4" .
Part 3 AT- 6 1
❏ AT-219, "Cannot Be Changed to Manual Mode" .
❏ AT-219, "
A/T Does Not Shift: 5th Gear → 4th Gear" .
❏ AT-221, "
A/T Does Not Shift: 4th Gear → 3rd Gear" .
❏ AT-223, "
A/T Does Not Shift: 3rd Gear → 2nd Gear" .
❏ AT-225, "
A/T Does Not Shift: 2nd Gear → 1st Gear" .
❏ AT-227, "
Vehicle Does Not Decelerate by Engine Brake" .
❏ Perform self-diagnostics. Enter checks for detected items. AT- 9 2
, AT-102 .
❏ AT-104, "
DTC U1000 CAN COMMUNICATION LINE" .
❏ AT-107, "
DTC P0615 START SIGNAL CIRCUIT" .
❏ AT- 111 , "
DTC P0700 TCM"
❏ AT- 11 2 , "DTC P0705 PARK/NEUTRAL POSITION SWITCH" .
❏ AT- 11 6 , "
DTC P0717 TURBINE REVOLUTION SENSOR" .
❏ AT- 11 8 , "
DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)" .
❏ AT-123, "
DTC P0725 ENGINE SPEED SIGNAL" .
❏ AT-125, "
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE" .
❏ AT-127, "
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)" .
❏ AT-129, "
DTC P0745 LINE PRESSURE SOLENOID VALVE" .
❏ AT-131, "
DTC P1705 THROTTLE POSITION SENSOR" .
❏ AT-134, "
DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT" .
❏ AT-139, "
DTC P1721 VEHICLE SPEED SENSOR MTR" .
❏ AT-141, "
DTC P1730 A/T INTERLOCK" .
❏ AT-144, "
DTC P1731 A/T 1ST ENGINE BRAKING" .
❏ AT-146, "
DTC P1752 INPUT CLUTCH SOLENOID VALVE" .
❏ AT-148, "
DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION" .
❏ AT-150, "
DTC P1757 FRONT BRAKE SOLENOID VALVE" .
❏ AT-152, "
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION" .
❏ AT-154, "
DTC P1762 DIRECT CLUTCH SOLENOID VALVE" .
❏ AT-156, "
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION" .
❏ AT-158, "
DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE" .
❏ AT-160, "
DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION" .
❏ AT-162, "
DTC P1772 LOW COAST BRAKE SOLENOID VALVE" .
❏ AT-164, "
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION" .
❏ AT-166, "
DTC P1815 MANUAL MODE SWITCH" .
❏ AT-171, "
DTC P1841 ATF PRESSURE SWITCH 1" .
❏ AT-173, "
DTC P1843 ATF PRESSURE SWITCH 3" .
❏ AT-175, "
DTC P1845 ATF PRESSURE SWITCH 5" .
❏ AT-177, "
DTC P1846 ATF PRESSURE SWITCH 6" .
5 ❏ Inspect each system for items found to be NG in the self-diagnostics and repair or replace the malfunctioning parts.
6 ❏ Perform all road tests and enter the checks again for the required items. AT- 5 6
7 ❏
For any remaining NG items, perform the “diagnostics procedure” and repair or replace the malfunctioning
parts. See the chart for diagnostics by symptoms. (This chart also contains other symptoms and inspection pro-
cedures.) AT- 6 4
8
❏ Erase the results of the self-diagnostics from the TCM. AT- 9 5,
AT-
102

AT-56
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Judgement of Line Pressure Test
ROAD TEST
Description

The road test checks overall performance of the A/T and analyzes possible malfunction causes.

The road test is carried out in the following three stages.
1. Check before engine is started. Refer to AT- 5 7
.
2. Check at idle. Refer to AT- 5 7
.
3. Cruise test

Inspect all the items from Part 1 to Part 3. Refer to AT- 5 8 , AT- 6 0 , AT- 6 1 .

Before beginning the road test, check the test procedure and inspection items.

Test all inspection items until the symptom is uncovered. Diagnose NG items when all road tests are com-
plete.
Judgement Possible cause
Idle speed Low for all positions
(“P”, “R”, “N”, “D”,
“M”) Possible causes include malfunctions in the pressure supply system and low oil pump output.
For example

Oil pump wear

Pressure regulator valve or plug sticking or spring fatigue

Oil strainer
oil pump
pressure regulator valve passage oil leak

Engine idle speed too low
Only low for a spe-
cific position Possible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.
High Possible causes include a sensor malfunction or malfunction in the line pressure adjustment func-
tion.
For example

Accelerator pedal position signal malfunction

ATF temperature sensor malfunction

Line pressure solenoid malfunction (sticking in OFF state, filter clog, cut line)

Pressure regulator valve or plug sticking
Stall speed Line pressure does
not rise higher than
the line pressure for
idle. Possible causes include a sensor malfunction or malfunction in the pressure adjustment function.
For example

Accelerator pedal position signal malfunction

TCM breakdown

Line pressure solenoid malfunction (shorting, sticking in ON state)

Pressure regulator valve or plug sticking

Pilot valve sticking or pilot filter clogged
The pressure rises,
but does not enter
the standard posi-
tion. Possible causes include malfunctions in the pressure supply system and malfunction in the pres-
sure adjustment function.
For example

Accelerator pedal position signal malfunction

Line pressure solenoid malfunction (sticking, filter clog)

Pressure regulator valve or plug sticking

Pilot valve sticking or pilot filter clogged
Only low for a spe-
cific position Possible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.