Page 1529 of 2572

E74263
Multiplex Network Body ECU
Connector Front View:
B10
B10-10
B10-14
B10-15
B10-16 B10-17 B10-18
- DIAGNOSTICSLIGHTING SYSTEM
05-1587
1777 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
1 INSPECT MULTIPLEX NETWORK BODY ECU
(a) Disconnect the B10 connector from the multiplex network body ECU.
(b) Measure the voltage according to the value(s) in the table below.
Standard:
Tester connectionConditionSpecified condition
B10-10 - Body groundFront fog light switch OFF " ON10 kW or higher " Below 1 W
B10-14 - Body groundHeadlamp Dimmer switch LOW " HIGH10 kW or higher " Below 1 W
B10-15 - Body groundHeadlamp Dimmer switch LOW " FLASH10 kW or higher " Below 1 W
B10-16 - Body groundLight control switch OFF " AUTO10 kW or higher " Below 1 W
B10-17 - Body groundLight control switch OFF " HEAD10 kW or higher " Below 1 W
B10-18 - Body groundLight control switch OFF " TAIL10 kW or higher " Below 1 W
NG Go to step 2
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
(SEE PAGE 05-1538)
Page 1530 of 2572

E11948
Connector Front View:
C13
05-1588
- DIAGNOSTICSLIGHTING SYSTEM
1778 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
2 INSPECT HEADLAMP DIMMER SWITCH ASSY
(a) Inspect light control switch (when headlamp is malfunc-
tioning).
(1) Measure the resistance according to the value(s) in
the table below.
Standard:
Tester connectionConditionSpecified condition
12 - 16
13 - 16
14 - 16
OFF10 kW or higher
14 - 16TAILBelow 1 W
13 - 16
14 - 16HEADBelow 1 W
12 - 16AUTOBelow 1 W
(b) Inspect headlamp dimmer switch (when headlamp is mal-
functioning).
(1) Measure the resistance according to the value(s) in
the table below.
Standard:
Tester connectionConditionSpecified condition
16 - 17LOWBelow 1 W
7 - 16HIGHBelow 1 W
7 - 16
8 - 16FLASHBelow 1 W
(c) Inspect front fog light switch (when fog lamp is malfunc-
tioning).
(1) Measure the resistance according to the value(s) in
the table below.
Standard:
Tester connectionConditionSpecified condition
10 - 11OFF10 kW or higher
10 - 11ONBelow 1 W
NG REPLACE HEADLAMP DIMMER SWITCH ASSY
(SEE PAGE 65-25)
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR
Page 1531 of 2572
E74076
Engine Room J/B
Body ECU
HEAD LAMP Relay
Engine Room R/B
H-LP RH LWR
H-LP LH LWR
H4
Headlamp RH (Low)H2
Headlamp LH (Low)
F7
FL Block
Battery FL MAINHRLY MAIN
L-R
R-B
W-B R-W
W-B R-Y
J3
J/C
EA3
B11 R 1
2B
1
2G 3
2 4
1 2 1 1
2I4
IK3
2
2
221
21
21
21
31W W
A
A 05-1556
- DIAGNOSTICSLIGHTING SYSTEM
1746 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
HEADLIGHT RELAY CIRCUIT
CIRCUIT DESCRIPTION
The multiplex network body ECU controls the HEAD relay when a signal is received from the headlamp dim-
mer switch assy.
WIRING DIAGRAM
05IQ9-01
Page 1532 of 2572

E74263
B11
B11-3 Multiplex Network Body ECU
Connector Front View:
- DIAGNOSTICSLIGHTING SYSTEM
05-1557
1747 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
1 PERFORM ACTIVE TEST USING HAND-HELD TESTER
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the hand-held tester main switch on.
(c) Select the item below in the ACTIVE TEST and then check the relay operation.
BODY NO.1 (MULTIPLEX NETWORK BODY ECU):
ItemTest DetailsDiagnostic Note
HEAD LIGHTHeadlamp relay ON/OFF-
OK: Headlamp comes on.
NG Go to step 2
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
(SEE PAGE 05-1538)
2 INSPECT MULTIPLEX NETWORK BODY ECU
(a) Disconnect the B11 connector from the multiplex network body ECU.
(b) Using a service wire, connect B11-3 of the wire harness side and body ground.
OK: Headlamp comes on.
NG Go to step 3
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
(SEE PAGE 05-1538)
Page 1533 of 2572
E72974
2B
2B-1 Engine Room J/B
Connector Front View:
05-1558
- DIAGNOSTICSLIGHTING SYSTEM
1748 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
3 INSPECT ENGINE ROOM J/B
(a) Disconnect the 2B connector from the engine room J/B.
(b) Using a service wire, connect 2B-1 of the engine room J/B side and body ground.
OK: Headlamp comes on.
NG Go to step 4
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM J/B - MULTIPLEX NETWORK
BODY ECU)
Page 1534 of 2572
E72974
2G
2G-1 Engine Room J/B
Connector Front View:
- DIAGNOSTICSLIGHTING SYSTEM
05-1559
1749 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
4 INSPECT ENGINE ROOM J/B
(a) Measure the voltage according to the value(s) in the table below.
Standard:
Tester connectionConditionSpecified condition
2G-1 - Body groundConnect 2B-1 and body ground10 to 14 V
NG Go to step 5
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR (EACH OF HEADLAMP CIRCUIT)
Page 1535 of 2572
E72974
2B
2B-1 Engine Room J/B
Connector Front View:
05-1560
- DIAGNOSTICSLIGHTING SYSTEM
1750 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
5 INSPECT ENGINE ROOM J/B
(a) Measure the voltage according to the value(s) in the table below.
Standard:
Tester connectionConditionSpecified condition
2B-1 - Body groundAlways10 to 14 V
NG Go to step 6
OK
REPLACE ENGINE ROOM J/B
Page 1536 of 2572
E72974
2I
2I-1 Engine Room J/B
Connector Front View:
- DIAGNOSTICSLIGHTING SYSTEM
05-1561
1751 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
6 CHECK HARNESS AND CONNECTOR(POWER SOURCE CIRCUIT)
(a) Disconnect the 2I connector from the engine room J/B.
(b) Measure the voltage according to the value(s) in the table below.
Standard:
Tester connectionConditionSpecified condition
2I-1 - Body groundAlways10 to 14 V
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
REPLACE ENGINE ROOM J/B