TOYOTA SEQUOIA 2001 Service Repair Manual

H40173G27651H23482
DLC3:
TC
Airbag Sensor Assembly:
A20
TC
D6
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±1499
1693 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
CAUTION:
Be sure to perform the following procedures before troubleshooting to avoid unexpected airbag de-
ployment.
(a) Turn the ignition switch to the LOCK position.
(b) Disconnect the negative (±) terminal cable from the battery, and wait for at least 90 seconds.
(c) Disconnect the connectors from the airbag sensor assembly.
(d) Disconnect the connectors from the steering wheel pad.
(e) Disconnect the connectors from the front passenger airbag assembly.
(f) w/ Side and curtain shield airbag:
Disconnect the connectors from the side airbag assembly LH and RH.
(g) w/ Side and curtain shield airbag:
Disconnect the connectors from the curtain shield airbag assembly LH and RH.
(h) Disconnect the connectors from the front seat outer belt LH and RH.
1 Check wire harness (DLC3 ± airbag sensor assembly).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
D6±13 (TC) ±
A20±15 (TC)AlwaysBelow 1 W
NG Repair or replace wire harness (TC of DLC3 ± TC
of airbag sensor assembly).
OK

H23483CG
DLC3:
D6
H23040TC
A20
DI±1500
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1694 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check wire harness (CG of DLC3 ± body ground).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
D6±4 (CG) ± Body groundAlwaysBelow 1 W
NG Repair or replace wire harness (CG of DLC3 to
body ground).
OK
3 Check wire harness (TC of airbag sensor assembly ± body ground).
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester ConnectionConditionSpecified Condition
A20±15 (TC) ±
Body groundAlways1 MW or higher
NG Repair or replace wire harness or each ECU.
OK
Replace airbag sensor assembly (see page RS±82).

DIDDW±01
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI±1501
1695 Author: Date:
2005 SEQUOIA (RM1146U)
POWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
PRECAUTION
NOTICE:
When disconnecting the battery terminal, initialize the following system after the terminal is recon-
nected.
System NameSee Page
Back Door Power Window Control SystemBE±77

DIDDX±01
I28733
Instrument Panel J/B

ECU±IG Fuse

PWR SEAT Fuse
Power Seat Motor (Reclining) Lumbar Support Control Motor
Seat Memory Switch
Power Seat Motor (Rear Lifter)
Lumbar Support Control Switch
Position Control ECU & Switch Assy
Power Seat Motor (Front Vertical)Power Seat Motor (Slide)
DI±1502± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
1696 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

DIDDZ±01
I28552
Position Control ECU
& Switch Assy
Park/Neutral
Position Switch
Combination
MeterPower Seat Motor
Driver Side (Reclining)
Power Seat Motor
Driver Side (Slide) Power Seat Motor
Driver Side (Front Vertical) Power Seat Motor
Driver Side (Lifter)
Front Door Courtesy
Light Switch Assy Seat Memory Switch Lumbar
Support
Control
MotorLumbar Support
Control Switch To Battery
To Battery To Ignition SwitchECU±B
PWR SEATECU±IGSYSB
IG
+BRCL+
RCL±
LFT+
LFT±
FRV+
FRV±
SLD+
SLD±
SW1
SW2
MMRYDCTY
Key Unlock
Warning Switch
KSW
Body ECU
BEANTo Ignition Switch
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI±1503
1697 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

DIDE0±01
DI±1504± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
1698 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DESCRIPTION
The power seat control system (w/ memory) is equipped with the following functions:

Manual operation of the driver side seat.

Individual seat positions for two different drivers can be stored for the slide±reclining front±verti-
cal 8±way lifter.

Similarly, power mirror positions for two different drivers can be stored. These are stored/restored
with the seat positions.

The above operations are performed using serial communication.

As a safety precaution, the system disallows seat position restoration unless the ignition switch
is ON, and the park/neutral position switch is in the P (park) position.

Manual adjustment of the slide reclining lumbar can be performed even when the ECU is not
functional.
When the power seat control switch is operated, a command signal is sent to the position control ECU. The
position control ECU then activates the appropriate seat motor as needed. This memory system does not
use a seat position sensor. The seat position is detected by counting pulses that are output when the motor
turns. If there is no pulse output from the motor, the motor will stop operating. The ECU is designed so that
a malfunction of the seat memory system will not interfere with manual seat control. The seat memory switch
also sends signals to the position control ECU to memorize a given seat position. The seat memory switch
is later used to send signals to the position control ECU to return to one of the memorized positions.

DIDE1±01
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI±1505
1699 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
HINT:
Use this procedure to troubleshoot the front power seat control system with memory function.
1 Vehicle Brought To Workshop
NEXT
2 Customer Problem Analysis Check and Problem Symptom Check
(See page DI±1507)
NEXT
3 Problem Symptom Confirmation
Symptom Does Not Occur (Go to step 4)
Symptom Occurs (Go to step 5)
4 Symptom Simulation (See page IN±24)
NEXT
5 Check Multiplex Communication System (See page DI±1904)
Check if any DTCs are output.
HINT:
The position control ECU & switch assy of this system are connected to the multiplex communication system.
Therefore, before starting troubleshooting, make sure to check that there is no trouble in the multiplex com-
munication system.
Multiplex System DTC is Output (Proceed to
ºMultiplex Communication Systemº)
No Multiplex System DTC (Go to step 6)

DI±1506± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
1700 Author: Date:
2005 SEQUOIA (RM1146U)
6 Problem Symptoms Table (See page DI±1508)
NEXT
7 Identification of Problem
NEXT
8 Adjustment, Repair or Replace
NEXT
9 Confirmation Test
NEXT
End

DIDE2±01
Inspector 's Name:
Customer 's Name
Date Vehicle
Brought InProduction Date VIN
Licence Plate No.
Odometer Reading/ /
/ /
Date Problem First Occurred
Frequency Problem Occurs/ /
ConstantIntermittent ( times a day)
km
miles
All functions do not operate.
Weather Conditions
When Problem
OccurredWeather
Outdoor
TemperatureOnly onceFine
Various/Others
CloudyRainySnowy
Hot
Cold (
C (
F))
WarmCool
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.
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI±1507
1701 Author: Date:
2005 SEQUOIA (RM1146U)
CUSTOMER PROBLEM ANALYSIS CHECK

DIDE4±01
DI±1508± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
1702 Author: Date:
2005 SEQUOIA (RM1146U)
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.
SymptomSuspected AreaSee Page
Power seat does not operate (manual or memorized positions).1. Power source circuit
2. Position control ECU & switch assyDI±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 assyDI±1525
BO±112
One or all manual seat functions do not operate (memorized
positions OK).Position control ECU & switch assyBO±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 assyDI±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 assyDI±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 assyDI±1525
BO±112
Lumbar support does not operate.Lumbar support control switch circuitDI±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 assyDI±1904
BE±115
BE±115
BO±112