Toyota Sequoia (2005). Manual - part 428

DIDE2–01

Inspector’s Name:

Customer’s Name

Production Date

VIN

Licence Plate No.

Odometer Reading

/              /

/              /

Frequency Problem Occurs

/                            /

Constant

Intermittent (       times a day)

km

miles

All functions do not operate.

Weather Conditions
When Problem 
Occurred

Weather

Outdoor 
Temperature

Only once

Fine

Various/Others

Cloudy

Rainy

Snowy

Hot

Cold (     

C  (    

F))

Warm

Cool

Problem Symptoms

Sliding function does not operate.

Reclining function does not operate.

Front vertical function does not operate.

Lifter function does not operate.

Seat position memory function does not operate.

Others

POWER SEAT CONTROL SYSTEM Check Sheet

Lumbar support function does not operate.

–

DIAGNOSTICS

POWER SEAT CONTROL SYSTEM (w/ Driving Position 
Memory)

DI–1507

1701

CUSTOMER PROBLEM ANALYSIS CHECK

DIDE4–01

DI–1508

–

DIAGNOSTICS

POWER SEAT CONTROL SYSTEM (w/ Driving Position 
Memory)

1702

PROBLEM SYMPTOMS TABLE

HINT:

If the cause of the problem still cannot be determined after the corresponding inspection, proceed to
the next step shown in this table.

The system uses multiplex communication. Check for DTCs for the multiplex communication system
before performing the following inspection.

Symptom

Suspected Area

See Page

Power seat does not operate (manual or memorized positions).

1. Power source circuit

2. Position control ECU & switch assy

DI–1514

BO–112

One function of power seat does not operate (manual or memo-

rized positions).

1. Power seat motor circuit

2. Position control ECU & switch assy

DI–1525

BO–112

One or all manual seat functions do not operate (memorized

positions OK).

Position control ECU & switch assy

BO–112

Memory function does not operate.

1. Power source circuit

2. Power seat memory switch circuit

3. Park/neutral position switch circuit

4. Door courtesy switch circuit

5. Position control ECU & switch assy

DI–1514
DI–1518
DI–1528
DI–1533

BO–112

All memory functions do not operate or operate a little then stop

(manual functions OK).

1. Power source circuit

2. Position control ECU & switch assy

DI–1514

BO–112

One memory function does not operate or operates a little then

stops (manual functions OK).

1. Power seat motor circuit

2. Position control ECU & switch assy

DI–1525

BO–112

Lumbar support does not operate.

Lumbar support control switch circuit

DI–1521

The power seat control system does not control the storing and

restoring of the power mirror position.

1. Multiplex communication system

2. Driving position memory switch

3. Outer mirror assy

4. Position control ECU & switch assy

DI–1904

BE–115
BE–115

BO–112

DIDE5–01

I27716

M7

M6

–

DIAGNOSTICS

POWER SEAT CONTROL SYSTEM (w/ Driving Position 
Memory)

DI–1509

1703

TERMINALS OF ECU

1.

CHECK POSITION CONTROL ECU & SWITCH ASSY

(a)

Disconnect the M6 and M7 ECU & switch connectors.

(b)

Check the voltage of each terminal of the wire harness side connectors.
Standard:

Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

GND (M7–1) – 

Body ground

W–B – Body ground

Ground

Always

Below 1 V

+B (M7–5) – 

GND (M7–1)

L–O – W–B

Battery

Always

10 to 14 V

SYSB (M6–8) – 

GND (M7–1)

W–R – W–B

Power source

Always

10 to 14 V

IG (M6–4) – GND (M7–1)

B–R – W–B

Ignition switch

Ignition switch OFF 

→

 ON

Below 1 V 

→

 10 to 14 V

MPX1 (M6–1) – 

GND (M7–1)

W – W–B

Communication signal

Always

10 k

Ω

 or higher

If the result is not as specified, there may be a malfunction on the wire harness side.
(c)

Reconnect the M6 and M7 ECU & switch connectors.

(d)

Check the voltage of each terminal of the connectors.
Standard:

Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

SLD+ (M7–2) – 

GND (M7–1)

L – W–B

Sliding motor signal

(Forward)

Seat moving forward using

sliding switch 

→

 Others

10 to 14 V 

→

 Below 1 V

SLD– (M7–3) – 

GND (M7–1)

Y – W–B

Sliding motor signal 

(Rearward)

Seat moving rearward us-

ing sliding switch 

→

 Others

10 to 14 V 

→

 Below 1 V

FRV+ (M7–6) – 

GND (M7–1)

G – W–B

Front vertical motor signal 

(Upward)

Seat cushion front portion
raising using front vertical

switch 

→

 Others

10 to 14 V 

→

 Below 1 V

FRV– (M7–4) – 

GND (M7–1)

B – W–B

Front vertical motor signal

(Downward)

Seat cushion front portion

lowering using front vertical

switch 

→

 Others

10 to 14 V 

→

 Below 1 V

LFT+ (M7–7) – 

GND (M7–1)

W – W–B

Lifter motor signal 

(Upward)

Seat raising using lifter

switch 

→

 Others

10 to 14 V 

→

 Below 1 V

LFT– (M7–9) – 

GND (M7–1)

V – W–B

Lifter motor signal 

(Downward)

Seat lowering using lifter

switch 

→

 Others

10 to 14 V 

→

 Below 1 V

DI–1510

–

DIAGNOSTICS

POWER SEAT CONTROL SYSTEM (w/ Driving Position 
Memory)

1704

RCL+ (M7–8) – 

GND (M7–1)

P – W–B

Reclining motor signal 

(Forward)

Seat back moving forward

using reclining switch 

→

Others

10 to 14 V 

→

 Below 1 V

RCL– (M7–10) – 

GND (M7–1)

BR – W–B

Reclining motor signal

(Rearward)

Seat back moving rear-

ward using reclining switch

→

 Others

10 to 14 V 

→

 Below 1 V

If the result is not as specified, the position control ECU & switch assy may be malfunctioning.