Operating Light Control Rheostat does not Change Light Brightness: Procedure

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

   OK

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

   COMBINATION METER:
   
   

   Item	Measurement Item/Range (Display)	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	-

NG → See step   2 

OK → See step   4 

Fig 1: Identifying L8 Rheostat Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the rheostat. Refer to REMOVAL .
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 1 Ω
   	UP switch is not pushed	10 kΩ or higher
   7 (DOWN) - 5 (E)	DOWN switch pushed	Below 1 Ω
   	DOWN switch is not pushed	10 kΩ or higher

NG → See step   5 

OK: Go to next step 

Fig 2: Identifying L10 ECU Connector & L8 Rheostat Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the L10 ECU connector.
2. Disconnect the L8 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) - L8-3 (UP)	Always	Below 1 Ω
   L10-7 (RHDW) - L8-7 (DOWN)
   L8-5 (E) - Body ground
   L10-8 (RHUP) or L8-3 (UP) - Body ground	Always	10 kΩ or higher
   L10-7 (RHDW) or L8-7 (DOWN) - Body ground

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4