Inspection Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch on (IG) and the tester on.
3. Operate the Techstream according to the display and select "DATA LIST" (See DATA LIST / ACTIVE TEST  ).

   Body Electrical / Combination Meter / Data List: 

   BODY ELECTRICAL / COMBINATION METER / DATA LIST
   
   

   Item	Measurement Item / Range	Normal Condition	Diagnostic Note
   Tail Cancel SW	Tail cancel switch ON or OFF	ON: Headlight dimmer switch (Light control switch) → TAIL or HEAD OFF: Headlight dimmer switch (Light control switch) → OFF	-
   Rheostat value	Rheostat volume Min.: 0 Max.: 100	Light control rheostat switch is dark → bright	Unit: %

   OK: 

   Light brightness can be changed within the specified range by actual operation. 

NG: Go to step 2 

OK : REPLACE COMBINATION METER ASSEMBLY  (See REMOVAL  ).

1. Remove the PANEL fuse from the main body ECU.
2. Measure the resistance according to the value in the table below.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Condition	Specified Condition
   PANEL fuse	Always	Below 1 Ω

   Fig 1: Identifying PANEL Fuse

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Reinstall the PANEL fuse.

NG : REPLACE FUSE 

OK: Go to next step 

1. Disconnect the C30 light control rheostat connector.
2. Measure the voltage according to the value in the table below.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Switch Condition	Specified Condition
   C30-5 (T) - Body ground	Ignition switch on (IG), light control switch on (TAIL)	11 to 14 V

   Fig 2: Identifying C30 Light Control Rheostat Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Reconnect the light control rheostat connector.

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the C37 combination meter assembly connector.
2. Disconnect the C30 light control rheostat connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Condition	Specified Condition
   C30-5 (T) - C37-13 (ILL+)	Always	Below 1 Ω
   C30-2 (RV) - C37-6 (ILL-)	Always	Below 1 Ω
   C30-8 (TC) - C37-14 (TC)	Always	Below 1 Ω
   C30-3 (E) - Body ground	Always	Below 1 Ω
   C30-5 (T) or C37-13 (ILL+) - Body ground	Always	10 kΩ or higher
   30-2(RV) or C37-6(ILL-) - Body ground	Always	10 kΩ or higher
   C30-3 (E) or C37-14 (TC) - Body ground	Always	10 kΩ or higher

   Fig 3: Checking Harness And Connector (Combination Meter - Light Control Rheostat)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Reconnect the combination meter assembly connector.
5. Reconnect the light control rheostat connector.

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the light control rheostat but without disconnecting the connector.
2. Turn the ignition switch on (IG).
3. Using an oscilloscope, check the signal waveform of the light control rheostat.
   SIGNAL WAVEFORM REFERENCE
   
   

   Item	Contents
   Terminal connection	C30-2 (RV) - Body ground
   Tool setting	5V/DIV, 50 ms /DIV
   Vehicle condition	Ignition switch on (IG)

   Fig 4: Identifying C30 Light Control Rheostat Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: 

   Waveform is as shown in  Fig 4 . 

   HINT:

   Duty ratio changes as the illumination dims. (A becomes longer)

4. Reinstall the light control rheostat.

NG : REPLACE LIGHT CONTROL RHEOSTAT  (See REMOVAL  ).

OK : REPLACE COMBINATION METER ASSEMBLY  (See REMOVAL  ).