2001 TOYOTA SEQUOIA ECU

DI±1516± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
1710 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check fuse (PWR SEAT, ECU±IG, AM1).
PREPARATION:
Remove the PWR SEAT, ECU±IG and AM1 fuses from the instrument panel J/B.
CHECK:
Measure the resistance.
OK:
Below 1 W
NG Replace fuse.
OK

I28698
Position Control ECU & Switch Assy
Wire Harness Side
Connector Front View:
M7
M6
GND
+BIG
SYSB
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI±1517
1711 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect position control ECU & switch assy.
PREPARATION:
Disconnect the M6 and M7 ECU connectors.
CHECK:
(a) Measure the voltage of each terminal of the wire harness side connectors.
OK:
Tester Connection (Symbol)ConditionSpecified Condition
M7±5 (+B) ± Body groundAlways10 to 14 V
M6±8 (SYSB) ± Body groundAlways10 to 14 V
M6±4 (IG) ± Body groundIgnition switch OFF " ONBelow 1 V " 10 to 14 V
(b) Measure the resistance between the M7 ECU wire harness side connector and body ground.
OK:
Tester Connection (Symbol)Specified Condition
M7±1 (GND) ± Body groundBelow 1 W
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown in
problem symptoms table (See page
DI±1508).

I28447
D24
Seat Memory SwitchBody ECU
SET
4 3 2 1
W±BL
L±Y
G23
22 24
B6
AM1
M2 MM
B6
B6 1
2
EJ8 J/C
IE M1
M2 MRY DI±1518
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
1712 Author: Date:
2005 SEQUOIA (RM1146U)
Memory switch circuit
CIRCUIT DESCRIPTION
The seat memory switch sends signals to the position control ECU & switch assy via multiplex communica-
tion to memorize a given seat position. This memory system does not use a position sensor. The seat posi-
tion 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 seat memory switch is later used to send signals to the position
control ECU to return to one of the memorized positions.
The power seat memory operation is performed only when the ignition switch is in the ON position and the
park/neutral position switch is in the P (park) position.
WIRING DIAGRAM
DIDE8±01

I27700
B6
Body ECU Wire Harness View:
MM
M1M2
DI±1520± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
1714 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check harness and connector (Body ECU & seat memory switch ± body ground).
PREPARATION:
(a) Reconnect the seat memory switch connector.
(b) Disconnect the B6 body ECU connector.
CHECK:
Measure the resistance of each terminal, as shown in the il-
lustration and table.
OK:
Tester Connection
(Symbol)Switch PositionSpecified Condition
B6±23 (M1) ±
Body groundMemory switch 1 OFF "
ON10 kW or higher"
Below 1 W
B6±24 (MM) ±
Body groundSET switch OFF " ON10 kW or higher"
Below 1 W
B6±22 (M2) ±
Body groundMemory switch 2 OFF "
ON10 kW or higher"
Below 1 W
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown in
problem symptoms table (See page
DI±1508).

I28448
PWR SEAT Instrument Panel J/B
ALT 161
1 2L±O L±O
BI29L4
Lumbar Support Control
Switch (Driver's Seat)
3 1 2
4
5 Rear Front
W
W±B W±B
BH BatteryLR1 L A
A
BI2 1G
1L
F10
FL BlockJ24 J/C
L3
Lumbar Support
Control Motor L±O
J24 J/C J/C
L±O
J31 J323
R B
H
B58C
G
BBB 2
W±B W±BE2E
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI±1521
1715 Author: Date:
2005 SEQUOIA (RM1146U)
Lumbar support control switch circuit
CIRCUIT DESCRIPTION
The lumbar support control switch that controls lumbar support is connected to the lumbar support control
motor via a wire harness. This circuit can freely operate regardless of the condition of the ECU.
WIRING DIAGRAM
DIDE9±01

I28449
Position Control
ECU & Switch
SLD± SLD+ FRV± FRV+
LFT± LFT+RCL± RCL+ 2 1
21
21
2 13 M7
M7
M7
M7
M7
M7
M7
M724 6
9 7 108
BR P14
Power Seat Motor
(Driver's Seat Front Vertical Control)
P16
Power Seat Motor
(Driver's Seat Reclining Control)P
V W B G
Y L P15
Power Seat Motor
(Driver 's Seat Rear Vertical Control)
P17
Power Seat Motor
(Driver's Seat Slide Control)
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI±1525
1719 Author: Date:
2005 SEQUOIA (RM1146U)
Power seat motor circuit
CIRCUIT DESCRIPTION
When the power seat control switch is operated, a command signal is sent to the position control ECU. The
position control ECU then controls 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 mal-
function of the seat memory system will not interfere with manual seat control.
When the position control ECU switch assy detects the low motor speed or abnormal activity, the system
stops the motor. When the motor continuously operates for 120 seconds or more, the system will stop the
motor until the switch is turned off.
WIRING DIAGRAM
DIDEB±01

I28704
Wire Harness Side:
Position Control ECU & Switch Assy
Power Seat Motor Assy P14
P16P15P17
M7
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)DI±1527
1721 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check harness and connector (Position control ECU & switch assy ± power seat
motor assy).
PREPARATION:
Disconnect the M7 ECU and P14, P15, P16 and P17 motor con-
nectors.
CHECK:
Measure the resistance of the wire harness side connectors.
OK:
Tester ConnectionSpecified Condition
M7±2 ± P17±1Below 1 W
M7±3 ± P17±2Below 1 W
M7±4 ± P14±2Below 1 W
M7±6 ± P14±1Below 1 W
M7±7 ± P15±2Below 1 W
M7±9 ± P15±1Below 1 W
M7±8 ± P16±2Below 1 W
M7±10 ± P16±1Below 1 W
M7±2 ± Body ground10 kW or higher
M7±3 ± Body ground10 kW or higher
M7±4 ± Body ground10 kW or higher
M7±6 ± Body ground10 kW or higher
M7±7 ± Body ground10 kW or higher
M7±8 ± Body ground10 kW or higher
M7±9 ± Body ground10 kW or higher
M7±10 ± Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown in
problem symptoms table
(See page DI±1508
).

I28451
BatteryJ/C
I18
Ignition SW
1
2
AM1IG1
5W BF10
FL Block
ALT
81L 1CInstrument Panel J/B
7 J52 J51
21AM1
6
1C4
1 78 L±Y1
MPX1 M6 WW
C5 C53430 Combination MeterPosition Control
ECU & Switch
P
L±Y
L±R
L±R CCPL RB 62 P1
Park/Neutral
Position Switch
B±Y
W±LGAUGEIPOIG49 BEAN
1D DI±1528
± DIAGNOSTICSPOWER SEAT CONTROL SYSTEM (w/ Driving Position
Memory)
1722 Author: Date:
2005 SEQUOIA (RM1146U)
Park/neutral position switch circuit
CIRCUIT DESCRIPTION
The power seat memory system operates only when the ignition switch is in the ON position and the park/
neutral position is in the P (park) position.
The position control ECU & switch assy detects the P position, via multiplex communication, through the
park/neutral position switch.
WIRING DIAGRAM
DIDEC±01