Operating Light Control Rheostat does not Change Light Brightness [08/2015 - 08/2017]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream ON.
4. Enter the following menus: Body Electrical / Combination Meter / Data List.
5. According to the display on the Techstream, read the Data List.
   COMBINATION METER
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   TAIL Cancel SW*1	TAIL cancel switch condition/ON or OFF	ON: TAIL cancel switch ON OFF: TAIL cancel switch OFF	-
   Rheostat value	Light control rheostat switch input/Min.: 0, Max.: 100	Light control rheostat switch is Dark (0) → Bright (100)	Unit: %

   1. *1: w/ TAIL Cancel Switch

   OK

   Light brightness can be changed within specified range by manual operation.

Result: 

OK 

REPLACE COMBINATION METER ASSEMBLY 

(Refer to REMOVAL [08/2015 - 08/2017] )

Result: 

NG 

See step  2

1. Remove the light control rheostat (Refer to REMOVAL [08/2015 - 08/2017] ).
2. Measure the resistance according to the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   W/O TAIL CANCEL SWITCH
   
   

   Tester Connection	Condition	Specified Condition
   3 (RV) - 1 (E)	Downward → Upward	See illustration
   7 (T) - 1 (E)	Always	8 to 12 kΩ

   W/ TAIL CANCEL SWITCH
   
   

   Tester Connection	Condition	Specified Condition
   3 (RV) - 1 (E)	Downward → Upward	See illustration
   5 (TC) - 7 (T)	Downward → Upward	10 kΩ or higher → Below 1 Ω
   7 (T) - 1 (E)	Always	8 to 12 kΩ

Result: 

NG 

REPLACE LIGHT CONTROL RHEOSTAT 

(Refer to REMOVAL [08/2015 - 08/2017] )

Result: 

OK 

See step  3

1. Disconnect the H37 meter connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Disconnect the J4 rheostat connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   W/O TAIL CANCEL SWITCH
   
   

   Tester Connection	Condition	Specified Condition
   H37-1 (RHIG) - J4-7 (T)	Always	Below 1 Ω
   H37-2 (TR) - J4-3 (RV)	Always	Below 1 Ω
   H37-3 (E2) - J4-1 (E)	Always	Below 1 Ω

   W/ TAIL CANCEL SWITCH
   
   

   Tester Connection	Condition	Specified Condition
   H37-1 (RHIG) - J4-7 (T)	Always	Below 1 Ω
   H37-2 (TR) - J4-3 (RV)	Always	Below 1 Ω
   H37-3 (E2) - J4-1 (E)	Always	Below 1 Ω
   H37-38 (TC) - J4-5 (TC)	Always	Below 1 Ω

Result: 

OK 

REPLACE COMBINATION METER ASSEMBLY 

(Refer to REMOVAL [08/2015 - 08/2017] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR