2001 TOYOTA SEQUOIA clutch

± DIAGNOSTICSAUTOMATIC TRANSMISSION
DI±625
819 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0776 Pressure Control Solenoid ºBº Performance
(Shift Solenoid Valve SL2)
SYSTEM DESCRIPTION
The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear
position (1st, 2nd, 3rd, 4th or 5th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical
problems of the shift solenoid valves, valve body or automatic transmission (clutch, brake or gear, etc.).
DTC No.DTC Detection ConditionTrouble Area
P0776The gear required by the ECM does not match the actual gear
when driving (2±trip detection logic)Shift solenoid valve SL2 remains open or closed
Valve body is blocked
Automatic transmission (clutch, brake or gear, etc.)
MONITOR DESCRIPTION
This DTC indicates ºstuck ON malfunctionº or ºstuck OFF malfunctionº of the shift solenoid valve SL2.
The ECM commands gear shifts by turning the shift solenoid valves ºON/OFFº. When the gear position com-
manded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL and stores
the DTC.
MONITOR STRATEGY
Related DTCsP0776Shift solenoid valve SL2/ON malfunction
Rid /C tMainShift solenoid valve SL2Required sensors/ComponentsSubSpeed sensor (NT), Speed sensor (NO), Crankshaft position sensor (NE)
Frequency of operationContinuous
ON malfunctions (A), (B) and
(C)0.4 sec.
DurationON malfunction (D)3 sec.
ON malfunction (E)0.5 sec.
MIL operation2 driving cycles
Sequence of operationNone
DIDJF±01

D14169
1±2 Shift Valve
Valve Body:
DI±636
± DIAGNOSTICSAUTOMATIC TRANSMISSION
830 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0781 1±2 Shift (1±2 Shift Valve)
SYSTEM DESCRIPTION
The 1±2 shift valve performs shifting to 1st gear and other
gears.
DTC No.DTC Detection ConditionTrouble Area
P0781The gear required by the ECM does not match the actual gear
when driving (2±trip detection logic)
Valve body is blocked up or stuck (1±2 shift valve)

Automatic transmission (clutch, brake or gear, etc.)
MONITOR DESCRIPTION
This DTC indicates that the 1±2 shift valve in the valve body is locked in the direction the spring compresses.
The ECM commands gear shifts by turning the shift solenoid valves ºON/OFFº and switching oil pressure
to the valves in the valve body.
The ECM calculates the ºactualº transmission gear by comparing the signals from the input speed sensor
(NCO) and the output speed sensor (SP2). The ECM can detect many mechanical problems in the shift sole-
noids, valve body, and the transmission clutches, brakes, and gears. If the ECM detects that the actual gear
position and the commanded gear position are different, it will illuminate the MIL and store the DTC .
MONITOR STRATEGY
Related DTCsP0781Valve body/Rationality check
MainValve body
Required sensors/ComponentsSubAutomatic transmission assembly, Speed sensor (NT), Speed sensor
(NO), Vehicle speed sensor, Throttle speed sensor
Frequency of operationContinuous
Conditions (A) and (B)0.4 sec.
DurationCondition (C)3 sec.Duration
Condition (D)0.5 sec.
MIL operation2 driving cycles
Sequence of operationNone
DIDJH±01

D14171
Line Pressure
Control Pressure
Current Flow to Solenoid
D14172
ON
OFF
1 cycle
D14173
DI±656
± DIAGNOSTICSAUTOMATIC TRANSMISSION
850 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2714 Pressure Control Solenoid ºDº Performance
(Shift Solenoid Valve SLT)
SYSTEM DESCRIPTION
The linear solenoid valve (SLT) controls the transmission line
pressure for smooth transmission operation based on signals
from the throttle position sensor and the vehicle speed sensor.
The ECM adjusts the duty cycle of the SLT solenoid valve to
control hydraulic line pressure coming from the primary regula-
tor valve. Appropriate line pressure assures smooth shifting
with varying engine outputs.
(*): Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle.
For example, if A is the period of continuity in one cycle, and B
is the period of non±continuity, then
Duty Ratio = A/(A + B) x 100 (%)
DTC No.DTC Detection ConditionTrouble Area
P2714
ECM detects a malfunction on SLT (ON side) according to the
revolution difference of the turbine and the output shaft, and
also by the oil pressure. (2±trip detection logic)
Shift solenoid valve SLT remains open or closed

Valve body is blocked

Automatic transmission (clutch, brake or gear, etc.)
MONITOR DESCRIPTION
The ECM calculates the amount of heat absorbed by the friction material based on the difference in revolu-
tion (clutch slippage) between the turbine and output shaft. The ECM turns on the MIL and outputs this DTC
when the amount of heat absorption exceeds the specified value.
When the shift solenoid valve SLT remains on, oil pressure goes down and clutch engagement force de-
creases.
NOTE: If you continue driving under these conditions, the clutch will burn out and the vehicle will no longer
be drivable.
DIDJL±01

D14174
ECM
SLT+
SLT± E713
12 B±R
G±Y E1 Electronically Controlled
Transmission Solenoid
E7 G
GR14
6 SLT+
SLT±+B DI±658
± DIAGNOSTICSAUTOMATIC TRANSMISSION
852 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL MALFUNCTION THRESHOLDS
Detection criteriaThreshold
Summation of C1 clutch heat generations
= R (Turbine speed ± Output speed x Temporary ratio)Specified value
WIRING DIAGRAM

D14175
G23415D14176
Lock±up
Operation
Pressure
Current Flow to Solenoid DI±672
± DIAGNOSTICSAUTOMATIC TRANSMISSION
866 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2757Torque Converter Clutch Pressure Control Solenoid
Performance(Shift Solenoid Valve SLU)
SYSTEM DESCRIPTION
The ECM uses the signals from the throttle position sensor, Air±
flow meter, turbine (input) speed sensor, output speed sensor
and crankshaft position sensor to monitor the engagement
condition of the lock±up clutch.
Then the ECM compares the engagement condition of the
lock±up clutch with the lock±up schedule in the ECM memory
to detect a mechanical problems of the shift solenoid valve
SLU, valve body and torque converter clutch.
DTC No.DTC Detection ConditionTrouble Area
P2757
Lock±up does not occur when driving in the lock±up range
(normal driving at 80 km/h [50 mph]), or lock±up remains ON
in the lock±up OFF range.
(2±trip detection logic)
Shift solenoid valve SLU remains open or closed

Valve body is blocked

Torque converter clutch

Automatic transmission (clutch, brake or gear, etc.)

Line pressure is too low
DIDJO±01

± DIAGNOSTICSAUTOMATIC TRANSMISSION
DI±673
867 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR DESCRIPTION
Torque converter lock±up is controlled by the ECM based on the turbine (input) speed sensor NT, output
speed sensor SP2, engine rpm, engine load, engine temperature, vehicle speed, transmission temperature,
and gear selection. The ECM determines the lock±up status of the torque converter by comparing the engine
rpm (NE) to the input turbine rpm (NT). The ECM calculates the actual transmission gear by comparing input
turbine rpm (NT) to output shaft rpm (SP2). When conditions are appropriate, the ECM requests ºlock±upº
by applying control voltage to the shift solenoid SLU. When the SLU is turned on, it applies pressure to the
lock±up relay valve and locks the torque converter clutch.
If the ECM detects no lock±up after lock±up has been requested or if it detects lock±up when it is not re-
quested, the ECM interprets this as a fault in the shift solenoid valve SLU or lock±up system performance.
The ECM will turn on the MIL and store the DTC.
Example:
When any of the following is met, the system judges it as a malfunction.
(a) There is a difference in rotation between the input side (engine speed) and output side (input turbine
speed) of the torque converter when the ECM commands lock±up.
(Engine speed is at least 70 rpm greater than input turbine speed.)
(b) There is no difference in rotation between the input side (engine speed) and output side (input turbine
speed) of the torque converter when the ECM commands lock±up off.
(The difference between engine speed and input turbine speed is less than 35 rpm.)
MONITOR STRATEGY
RltdDTCP2757Shift solenoid valve SLU/OFF malfunctionRelated DTCsP2757Shift solenoid valve SLU/ON malfunction
MainShift solenoid valve SLU
Required sensors/ComponentsSubValve body, Vehicle speed sensor, Throttle position sensor, Speed sensor
(NT), Speed sensor (NO)
Frequency of operationContinuous
OFF malfunction (A)2 sec.
DurationOFF malfunction (B)0.4 sec.Duration
ON malfunction1.8 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
All:
Turbine speed sensor circuitNot circuit malfunction
Output speed sensor circuitNot circuit malfunction
Shift solenoid valve S1 circuitNot circuit malfunction
Shift solenoid valve S2 circuitNot circuit malfunction
Shift solenoid valve SR circuitNot circuit malfunction
Torque converter clutch pressure control
solenoid circuitNot circuit malfunction
KCS sensor circuitNot circuit malfunction
ETCS (Electric throttle control system)Not system down
Transmission rangeºDº

± DIAGNOSTICSAUTOMATIC TRANSMISSION
DI±679
873 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check torque converter clutch (See page AT±30).
OK:
The torque converter clutch operates normally.
NG Replace the torque converter clutch
(See page AT±25).
OK
Repair or replace transmission (See page
AT±25).

Current flow to solenoid
Lock±up
Operation
Pressure
BE4056D00160
1 cycle ON
OFF DI±680
± DIAGNOSTICSAUTOMATIC TRANSMISSION
874 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2759Torque Converter Clutch Pressure Control Solenoid
Control Circuit Electrical(Shift Solenoid Valve SLU)
CIRCUIT DESCRIPTION
The amount of current flow to the solenoid is controlled by the
(*) duty ratio of the ECM output signal. The higher the duty ratio
becomes, the higher the lock±up hydraulic pressure becomes
during the lock±up operation.
(*) Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle.
For example, if A is the period of continuity in one cycle, and B
is the period of non±continuity, then
Duty Ratio = A/(A + B) x 100 (%)
DTC No.DTC detection conditionTrouble Area
P2759Open or short is detected in shift solenoid valve SLU circuit for
1 second or more while driving (1±trip detection logic).
Open or short in shift solenoid valve SLU circuit

Shift solenoid valve SLU

ECM
MONITOR DESCRIPTION
When an open or short in a shift solenoid valve (SLU) circuit is detected, the ECM determines there is a mal-
function. The ECM will turn on the MIL and store this DTC.
MONITOR STRATEGY
Related DTCsP2759Shift solenoid valve SLU/Range check
Required sensors/ComponentsShift solenoid valve SLU
Frequency of operationContinuous
Duration1 sec.
MIL operationImmediate
Sequence of operationNone
DIDJP±01