Inspection Procedure

1. Connect a Techstream to the DLC3.
2. Turn the ignition switch on 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
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Tail Cancel SW	Tail cancel switch ON or OFF	ON: Headlight dimmer switch (Light control switch) → OFF OFF: Headlight dimmer switch (Light control switch) → TAIL or HEAD	-
   Rheostat value	Rheostat volume Min.: 0 Max.: 100	Light control rheostat switch is dark (0) → bright (100)	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 PANEL1 fuse from the main body ECU.
2. Measure the resistance according to the value in the table below.

   Standard resistance 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester Connection	Condition	Specified Condition
   PANEL1 fuse	Always	Below 1 Ω

3. Reinstall the PANEL1 fuse.

NG: REPLACE FUSE 

Fig 1: Identifying PANEL1 Fuse In Main Body ECU

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to Next Step 

1. Disconnect the F28 light control rheostat connector.
2. Measure the voltage according to the value in the table below.

   Standard voltage 

   STANDARD VOLTAGE SPECIFICATIONS
   
   

   Tester Connection	Switch Condition	Specified Condition
   F28-5 (T) - Body ground	Ignition switch on, light control switch on (TAIL or HEAD)	11 to 14 V

3. Reconnect the light control rheostat connector.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

Fig 2: Identifying F28 Light Control Rheostat Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to Next Step 

1. Disconnect the F2 combination meter assembly connector.
2. Disconnect the F28 light control rheostat connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester Connection	Condition	Specified Condition
   F28-5 (T) - F2-7 (ILL+)	Always	Below 1 Ω
   F28-2 (RV) - F2-6 (ILL-)	Always	Below 1 Ω
   F28-8 (TC) - F2-8 (TC)	Always	Below 1 Ω
   F28-3 (E) - Body ground	Always	Below 1 Ω
   F28-5 (T) or F2-7 (ILL+) - Body ground	Always	10 kΩ or higher
   30-2 (RV) or F2-6 (ILL-) - Body ground	Always	10 kΩ or higher
   F28-8 (TC) or F2-8 (TC) - Body ground	Always	10 kΩ or higher

4. Reconnect the combination meter assembly connector.
5. Reconnect the light control rheostat connector.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

Fig 3: Identifying F2 Combination Meter Assembly Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to Next Step 

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

   Item	Contents
   Terminal connection	F28-2 (RV) - Body ground
   Tool setting	5V/DIV, 50 ms /DIV
   Vehicle condition	Ignition switch on

   OK: Waveform is as shown in the illustration. 

   HINT:

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

4. Reinstall the light control rheostat.

NG: REPLACE LIGHT CONTROL RHEOSTAT  (See LIGHT CONTROL RHEOSTAT  )

Fig 4: Identifying F28 Connector Terminals And Waveform Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : REPLACE COMBINATION METER ASSEMBLY  (See REMOVAL  )