Toyota Sequoia (2005). Manual - part 210

D12795

1

2

(–)

(+)

1

2

Shift Solenoid Valve SL2:

–

DIAGNOSTICS

AUTOMATIC TRANSMISSION

DI–635

829

3

Check shift solenoid valve SL2.

PREPARATION:
Remove the shift solenoid valve SL2 (See page 

AT–10

).

CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:

Tester Connection

Specified Condition

20



C (68



F)

1 – 2

5.0 to 5.6 

Ω

CHECK:
Connect the positive (+) lead with a 21 W bulb to terminal 2 and
the negative (–) lead to terminal 1 of the solenoid valve connec-
tor, then check the movement of the valve.
OK:

The solenoid makes an operating sound.

 

NG

Replace the shift solenoid valve SL2
(See page 

AT–10

).

OK

Repair or replace the transmission wire
(See page 

AT–7

).

D14169

1–2 Shift Valve

Valve Body:

DI–636

–

DIAGNOSTICS

AUTOMATIC TRANSMISSION

830

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 Condition

Trouble Area

P0781

The 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 ”ON/OFF” and switching oil pressure
to the valves in the valve body.
The ECM calculates the ”actual” 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 DTCs

P0781

Valve body/Rationality check

Main

Valve body

Required sensors/Components

Sub

Automatic transmission assembly, Speed sensor (NT), Speed sensor

(NO), Vehicle speed sensor, Throttle speed sensor

Frequency of operation

Continuous

Conditions (A) and (B)

0.4 sec.

Duration

Condition (C)

3 sec.

Duration

Condition (D)

0.5 sec.

MIL operation

2 driving cycles

Sequence of operation

None

DIDJH–01

–

DIAGNOSTICS

AUTOMATIC TRANSMISSION

DI–637

831

TYPICAL ENABLING CONDITIONS

It

Specification

Item

Minimum

Maximum

All:

Turbine speed sensor circuit

Not circuit malfunction

Output speed sensor circuit

Not circuit malfunction

Shift solenoid valve S1 circuit

Not circuit malfunction

Shift solenoid valve S2 circuit

Not circuit malfunction

Shift solenoid valve SR circuit

Not circuit malfunction

Shift solenoid valve SL1 circuit

Not circuit malfunction

Shift solenoid valve SL2 circuit

Not circuit malfunction

ECT (Engine coolant temperature) sensor

circuit

Not circuit malfunction

KCS sensor circuit

Not circuit malfunction

ETCS (Electric throttle control system)

Not system down

Transmission range

”D”

ECT

40

°

C (104

°

F) or more

–

Spark advance from Max. retard timing by

KCS control

0

°

 

CA or more

–

Engine

Starting

Transfer range

”HIGH”

*1

Transfer range ”HIGH” *1 (This condition is applied only 4WD)

*1 Following conditions met

 Vehicle speed sensor circuit

Not circuit malfunction

 Output shaft speed sensor circuit

Not circuit malfunction

 Transfer output speed

143 rpm or more

–

 NO/NOtf (Transfer input speed/Transfer

output speed)

0.9 to 1.1

Condition (A)

ECM selected gear

2nd

Vehicle speed

2 km/h (1.2 mph) or more

–

Output speed

2nd 

→

 1st down shift point or more

–

Throttle valve opening angle

7.0% or more at 2,000 rpm

(Conditions vary with engine speed)

–

Condition (B)

ECM selected gear

4th

Vehicle speed

2 km/h (1.2 mph) or more

–

Throttle valve opening angle

7.0% or more at 2,000 rpm

(Conditions vary with engine speed)

–

Condition (C)

Current ECM selected gear

5th

Last ECM selected gear

4th

Vehicle speed 

(During transition from 4th to 5th gear)

–

Less than 100 km/h (62.2 mph)

Condition (D)

ECM selected gear

5th

DI–638

–

DIAGNOSTICS

AUTOMATIC TRANSMISSION

832

Engine speed – Turbine speed (NE – NT)

(After transition from 4th to 5th gear)

–

Less than 150 rpm

Vehicle speed 

(After transition from 4th to 5th gear)

–

Less than 100 km/h (62.2 mph)

TYPICAL MALFUNCTION THRESHOLDS

Detection criteria

Threshold

Both of the following conditions are met: Condition (A), and Condition (B), (C) or (D)

Condition (A)

Turbine speed/Output speed

3.30 to 7.50

Condition (B)

Turbine speed/Output speed

1.28 to 1.53

Condition (C)

Turbine speed – Output speed x 4th gear ratio 

(NT – NO x 4th gear ratio)

1,000 rpm or more

Condition (D)

Turbine speed – Output speed x 5th gear ratio 

(NT – NO x 5th gear ratio)

1,000 rpm or more

INSPECTION PROCEDURE

1

Check other DTCs output (in addition to DTC P0781).

PREPARATION:
(a)

Turn the ignition switch off.

(b)

Connect the OBD II scan tool or hand–held tester to the DLC3.

(c)

Turn the ignition switch to the ON position.

(d)

Turn on the tester.

(e)

Select the item ”DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES”.

CHECK:
Read the DTCs using the OBD II scan tool or the hand–held tester.
RESULT:

Display (DTC output)

Proceed to

Only ”P0781” is output

A

”P0781” and other DTCs

B

HINT:
If any other codes besides ”P0781” are output, perform troubleshooting for those DTCs first.

B

Go to DTC chart (See page 

DI–573

).

A