Operating Light Control Rheostat does not Change Light Brightness (08/2010 - 08/2011): Procedure

1. Operate the Techstream according to the display and select the Data List. Refer to DATA LIST / ACTIVE TEST .
   COMBINATION METER
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Tail Cancel SW	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 fully turned left (0) → fully turned right (100)	Unit: %

   OK

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

NG → See step   5 

OK: Go to next step 

1. Inspect the light control rheostat.
   Fig 1: Light Control Rheostat Function Chart

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Remove the light control rheostat. Refer to REMOVAL .
   2. Measure the resistance according to the table below.

      Standard Resistance

      Tester Connection	Switch Condition	Specified Condition
      6 (TC) - 5 (T)	TAIL cancel switch off → on	10 kΩ or higher → Below 1 Ω
      5 (T) - 1 (E)	Always	10 kΩ +/- 20%
      7 (TR) - 1 (E)	Light control rheostat fully turned left → fully turned right	10 kΩ +/- 20% → Below 100 Ω

2. Inspect the ODO/TRIP switch.
   1. Measure the resistance according to the table below.

      Standard Resistance

      Tester Connection	Switch Condition	Specified Condition
      4 (A/B) - 1 (E)	ODO/TRIP switch on (Pushed)	Below 100 Ω
      	ODO/TRIP switch off (Not pushed)	1 MΩ or higher

NG → See step   6 

OK: Go to next step 

Fig 2: Identifying E77 And E9 Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the E77 meter connector.
2. Disconnect the E9 rheostat connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E77-32 (ILL+) - E9-5 (T)	Always	Below 1 Ω
   E77-33 (TR) - E9-7 (TR)
   E77-34 (E2) - E9-1 (E)
   E7-31 (TC) - E9-6 (TC)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the combination meter assembly with a new or normally operating one. Perform an operation inspection.

   OK

   Combination meter assembly operates normally.

NG → See step   7 

OK → END (COMBINATION METER IS DEFECTIVE)