Operating Light Control Rheostat does not Change Light Brightness [09/2015 - ]: Procedure

1. Operate the Techstream according to the display and select "Data List".
   COMBINATION METER
   
   

   Item	Measurement Item/Range	Normal Condition	Diagnostic Note
   Light Control Up Switch	Light control rheostat (UP) switch / ON or OFF	ON: Light control rheostat (UP) switch pushed OFF: Light control rheostat (UP) switch not pushed	-
   Light Control Down Switch	Light control rheostat (DOWN) switch / ON or OFF	ON: Light control rheostat (DOWN) switch pushed OFF: Light control rheostat (DOWN) switch not pushed	-

   OK

   Switch condition (ON/OFF) can be switched by actual operation.

Result:  OK

OK 

REPLACE NO. 1 METER ECU 

(Refer to DISASSEMBLY [09/2015 - ] )

Result:  NG

NG 

See step  2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the rheostat (Refer to REMOVAL [09/2015 - ] ).
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Switch Condition	Specified Condition
   3 (UP) - 5 (E)	UP switch is pushed	Below 200 Ω
   	UP switch is not pushed	1 MΩ or higher
   7 (DOWN) - 5 (E)	DOWN switch is pushed	Below 200 Ω
   	DOWN switch is not pushed	1 MΩ or higher

Result:  NG

NG 

REPLACE LIGHT CONTROL RHEOSTAT 

(Refer to REMOVAL [09/2015 - ] )

Result:  OK

OK 

See step  3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the L10 meter connector.
2. Disconnect the L163 rheostat connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   L10-8 (RHUP) - L163-3 (UP)	Always	Below 1 Ω
   L10-7 (RHDW) - L163-7 (DOWN)
   L163-5 (E) - Body ground
   L10-8 (RHUP) or L163-3 (UP) - Body ground	Always	10 kΩ or higher
   L10-7 (RHDW) or L163-7 (DOWN) - Body ground

Result:  OK

OK 

REPLACE NO. 1 METER ECU 

(Refer to DISASSEMBLY [09/2015 - ] )

Result:  NG

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR