Operating Light Control Rheostat does not Change Light Brightness: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical/Combination Meter/Data List.
5. Check the values by referring to the table below.
   COMBINATION METER
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Light Control Up SW	Light control rheostat up switch/OFF or ON	OFF: Light control rheostat up switch not pressed	-
   		ON: Light control rheostat up switch pressed
   Light Control Down SW	Light control rheostat down switch/OFF or ON	OFF: Light control rheostat down switch not pressed	-
   		ON: Light control rheostat down switch pressed

   OK

   The value displayed on the Techstream changes with the actual rheostat switch operation.

NG → See step   2 

OK → See step   4 

1. Remove the light control rheostat. Refer to REMOVAL .
   Fig 1: Identifying Light Control Rheostat

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   2 (UP) - 8 (E)	Light control rheostat up switch pressed	Below 1 Ω
   	Light control rheostat up switch not pressed	10 kΩ or higher
   1 (DOWN) - 8 (E)	Light control rheostat down switch pressed	Below 1 Ω
   	Light control rheostat down switch not pressed	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *1	Component without harness connected (Light Control Rheostat)

NG → See step   5 

OK: Go to next step 

1. Disconnect the F4 and F56 connectors.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F4-16 (RHUP) - F56-2 (UP)	Always	Below 1 Ω
   F4-16 (RHUP) - Body ground	Always	10 kΩ or higher
   F4-14 (RHDN) - F56-1 (DOWN)	Always	Below 1 Ω
   F4-14 (RHDN) - Body ground	Always	10 kΩ or higher
   F56-8 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4