
05-1 160
DIAGNOSTICS - LIGHTING SYSTEM 05BVV-01
IGNITION SWITCH CIRCUIT
CIRCUIT DESCRIPTION
This circuit detects the state of the ignition switch and send it to Multiplex network body ECU.
WIRING DIAGRAM
Multiplex Network
Body ECU
Driver Side Junction Block
ACC Relay
10 AM1 ECU ACC
W-L
1H 3 ACC
5 22
9
P
1H
2 1
I15 IG1 Relay
1 ECU-IG
Ignition Switch W
1A IG
ACC 3 5 3 15
29
B-Y B-Y
1H
1 AM1 IG1 2 2 1
16
1L
Fusible Link Block
1 ALT 1
W W W-B
F6 F7
W FL MAIN
Battery
IE
E68118
2005 SIENNA REPAIR MANUAL (RM1163U)
Author : Date : 1343
05-1 161
DIAGNOSTICS - LIGHTING SYSTEM
INSPECTION PROCEDURE
HINT:
Start the inspection from step 1 in the case of using the hand-held tester, and start from step 2 in the case
of not using the hand-held tester.
1 READ VALUE OF HAND-HELD TESTER
(a) Connect the hand-held tester to DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the items below in the DATA LIST, and read the displays on the hand-held tester.
BODY NO.1:
Measurement Item/
Item Normal Condition Diagnostic Note
Display (Range)
ACC SW signal/ ON: Ignition key is in ACC, ON or START position
ACC SW -
ON or OFF OFF: Ignition key is in OFF position
IG SW signal/ ON: Ignition key is in ON or START position
IG SW -
ON or OFF OFF: Ignition key is in OFF or ACC position
OK PROCEED TO NEXT CIRCUIT INSPECTION
SHOWN ON PROBLEM SYMPTOMS TABLE
(See page 05-1 131)
NG
2 INSPECT FUSE
(a) Inspect the ECU ACC fuse, ECU-IG fuse and AM1 fuse in instrument panel junction block assy.
NG REPLACE FUSE
OK
2005 SIENNA REPAIR MANUAL (RM1163U)
Author : Date : 1344
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DIAGNOSTICS - LIGHTING SYSTEM
3 INSPECT RELAY
(a) Inspect ACC relay continuity.
Standard:
Condition Tester connection Specified condition
Always 1-2 Continuity
Always 3-5 No continuity
Apply B+ between
3-5 Continuity
the terminal 1 and 2
E64835
(b) Inspect IG1 relay continuity.
Standard:
Condition Tester connection Specified condition
Always 1-2 Continuity
Always 3-5 No continuity
Apply B+ between
3-5 Continuity
the terminal 1 and 2
NG REPLACE RELAY
E64835
OK
2005 SIENNA REPAIR MANUAL (RM1163U)
Author : Date : 1345
05-1 163
DIAGNOSTICS - LIGHTING SYSTEM
4 INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSY(ACC, IG)
(a) Measure the voltage between the terminals as shown in the chart below.
Standard:
Tester connection Condition Specified condition
1H-9 - Body ground Ignition switch is OFF ACC, ON Below 1 V 10 to 14 V
1H-29 - Body ground Ignition switch is OFF ON Below 1 V 10 to 14 V
1H
E67349
OK PROCEED TO NEXT CIRCUIT INSPECTION
SHOWN ON PROBLEM SYMPTOMS TABLE
(See page 05-1 131)
NG
2005 SIENNA REPAIR MANUAL (RM1163U)
Author : Date : 1346
05-1 164
DIAGNOSTICS - LIGHTING SYSTEM
5 INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSY(+B)
(a) Measure voltage between the terminal 1A-1 of the instrument panel junction block assy and body
ground.
Standard:
Tester connection Specified voltage
1A-1 - Body ground 10 to 14 V
1A
E67348
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
2005 SIENNA REPAIR MANUAL (RM1163U)
Author : Date : 1347
05-1 165
DIAGNOSTICS - LIGHTING SYSTEM
6 INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSY
(a) Measure voltage between the terminal 1H-10 of the instrument panel junction block assy and body
ground.
Standard:
Tester connection Condition Specified voltage
1H-10 - Body ground Always 10 to 14 V
1H
E67349
NG REPLACE INSTRUMENT PANEL JUNCTION
BLOCK ASSY
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR
2005 SIENNA REPAIR MANUAL (RM1163U)
Author : Date : 1348