Operating Light Control Rheostat does not Change Light Brightness: Procedure

1. Confirm the symptoms.
   RESULT
   
   

   Result	Proceed to
   Meter illumination does not change when operating light control switch	A
   Dimmer function cannot be canceled	B

B → See step   5 

A: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the engine 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   3 

OK → See step   7 

1. Remove the light control rheostat. Refer to REMOVAL [06/2012 - ] .

   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
   
   

   *a	Component without harness connected (Light Control Rheostat)
   *b	Light control rheostat up switch
   *c	Light control rheostat down switch

NG → See step   8 

OK: Go to next step 

1. Disconnect the G3 meter connector.
2. Disconnect the G8 light control rheostat connector.
3. Measure the resistance according to the value(s) in the table below.
   STANDARD RESISTANCE
   
   

   Tester Connection	Condition	Specified Condition
   G3-6 (RHUP) - G8-2 (UP)	Always	Below 1 Ω
   G3-6 (RHUP) - Body ground	Always	10 kΩ or higher
   G3-7 (RHDW) - G8-1 (DOWN)	Always	Below 1 Ω
   G3-7 (RHDW) - Body ground	Always	10 kΩ or higher
   G8-8 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   7 

1. Remove the light control rheostat. Refer to REMOVAL [06/2012 - ] .

   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

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Light Control Rheostat)
   *b	Light control rheostat up switch
   *c	Light control rheostat down switch

NG → See step   8 

OK: Go to next step 

1. Disconnect the G3 meter connector.
2. Disconnect the G8 light control rheostat connector.
3. Measure the resistance according to the value(s) in the table below.
   STANDARD RESISTANCE
   
   

   Tester Connection	Condition	Specified Condition
   G3-6 (RHUP) - G8-2 (UP)	Always	Below 1 Ω
   G3-6 (RHUP) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   7