CIRCUIT INSPECTION Power Source Circuit

DI−723
DIAGNOSTICS
−
POWER SEAT CONTROL SYSTEM
CIRCUIT INSPECTION
Power Source Circuit
CIRCUIT DESCRIPTION
This circuit provides power to operate the Power Seat ECU.
The power seat switch is built into the Power Seat ECU.
However, the lumber support switch and the seat cushion switch are separated.
LEXUS LS430 (RM792E)
DI8KW−01
DI−724
−
DIAGNOSTICS
POWER SEAT CONTROL SYSTEM
WIRING DIAGRAM
7
7
BF1 BG1
(*1) (*2)
17 17
BF1 BG1
(*1) (*2)
13 13
BF1 BG1
(*1) (*2)
8
8
BF1 BG1
(*1) (*2)
W−B
W−B
(*2)
J22 *1
J27 *2
W−B (*1)
BR
A
J/C
R−L
B−R
Driver Side J/B
10 *1
5 *2
6 *1
1 *2
D27
1 *1
8 *2
D28
10 *1
15 *2
D28
14 *1
7 *2
D27
W−B
BR
R−L
B−R
Power Seat
ECU
GND
SGND
IG
+B
30A D P/SEAT
DJ
17
DI
7.5A MPX−IG
8 *1
7 *2
W−B
D−IG1 RELAY
3
5
17 *1
13 *2
DA
1
2
DG
1
DF
4 *1
6 *2
7.5A AM1
DE
I17 Ignition SW
W−L 1
AM1
IG1
R−W
2
A J/C E
J13
J14
R−W
FL Block
80A D−J/B
1
2
140A ALT
1
2
1
4A
B−L
20A D/C CUT
2
1
G
J11
V−Y
IR
*1: LHD Models
*2: RHD Models
LEXUS LS430 (RM792E)
J/C
G
J11
5
17
IC3 IG2
(*1) (*2)
V−Y
4 *1
8 *2
PE
V−Y
1
4C
B−W
4
Passenger
Side J/B
1 *1
7.5A MPX−B1
2 *2
PB
14 14
BF1 BG1
(*1) (*2)
R−L
9 *1
16 *2
D28 SYSB
V−Y
Battery
BL *1
BN *2
IG *1
IK *2
I17156
DI−725
DIAGNOSTICS
−
POWER SEAT CONTROL SYSTEM
INSPECTION PROCEDURE
1
Check D SEAT and MPX−B1 fuse.
CHECK:
Check continuity of D SEAT and MPX−B1 fuse.
OK:
Continuity
NG
Replace the failure fuse.
OK
2
Check voltage between terminals SYSB, +B, IG and GND of power seat ECU connector.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure voltage between terminals IG and GND.
OK:
Voltage: 10 − 14 V
PREPARATION:
(a) Turn the ignition switch OFF
(b) Disconnect the Power seat ECU connector.
CHECK:
Measure voltage between terminals SYSB, +B and GND.
OK
NG
LEXUS LS430 (RM792E)
Proceed to next circuit inspection shown on
problem symptoms table (See page DI−722).
DI−726
DIAGNOSTICS
3
−
POWER SEAT CONTROL SYSTEM
Check harness and connector between Power Seat ECU and body ground (See
page IN−35).
OK
NG
Proceed to next circuit inspection shown on
problem symptom table (See page DI−722).
LEXUS LS430 (RM792E)
Repair or replace harness or connector.

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