Inspection Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch on (IG).
3. Turn Techstream on.
4. Select the following menu items: Body Electrical / Main Body / Data List.
5. Read the display on Techstream.

   Main Body: 

   DATA LIST REFERENCE
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Dimmer Hi SW	Dimmer switch HIGH signal / ON or OFF	ON: Dimmer switch in HIGH or HIGH FLASH OFF: Dimmer switch in LOW	-
   Passing Light SW	Dimmer switch HIGH FLASH signal / ON or OFF	ON: Dimmer switch in HIGH FLASH OFF: Dimmer switch not in HIGH FLASH	-
   Front Fog Light SW	Front fog light switch signal / ON or OFF	ON: Fog light switch ON OFF: Fog light switch OFF	-
   Light Auto SW	Light control switch AUTO signal / ON or OFF	ON: Light control switch in AUTO OFF: Light control switch not in AUTO	-
   Headlight SW	Light control switch HEAD signal / ON or OFF	ON: Light control switch in HEAD OFF: Light control switch not in HEAD	-
   Taillight SW	Light control switch TAIL signal / ON or OFF	ON: Light control switch in TAIL or HEAD OFF: Light control switch in neither TAIL nor HEAD	-

   OK: 

   Normal conditions listed above are displayed. 

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  

NG: Go to next step 

1. Inspect the headlight dimmer switch assembly (See INSPECTION  ).

   OK: 

   Headlight dimmer switch assembly is normal. 

NG: REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY 

OK: Go to next step 

1. Disconnect the E21 headlight dimmer switch assembly connector.
2. Disconnect the E6 and E7 main body ECU connectors.
3. Disconnect the IG instrument panel J/B connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   RESISTANCE REFERENCE
   
   

   Tester Connection	Condition	Specified Condition
   E21-3 (LFG) - E21-16 (HL)	Always	Below 1 Ω
   E21-4 (BFG) - E6-28 (FFOG)	Always	Below 1 Ω
   E21-11 (HU) - IG-5 (HU)	Always	Below 1 Ω
   E21-17 (HF) - E7-13 (HF)	Always	Below 1 Ω
   E21-18 (T) - E7-23 (TAIL)	Always	Below 1 Ω
   E21-19 (A) - E7-21 (A)	Always	Below 1 Ω
   E21-20 (H) - E6-17 (HEAD)	Always	Below 1 Ω
   E21-3 (LFG) - Body ground	Always	10 kΩ or higher
   E21-4 (BFG) - Body ground	Always	10 kΩ or higher
   E21-11 (HU) - Body ground	Always	10 kΩ or higher
   E21-17 (HF) - Body ground	Always	10 kΩ or higher
   E21-18 (T) - Body ground	Always	10 kΩ or higher
   E21-19 (A) - Body ground	Always	10 kΩ or higher
   E21-20 (H) - Body ground	Always	10 kΩ or higher
   E21-12 (EL) - Body ground	Always	Below 1 Ω

Fig 1: Checking Harness And Connector (Instrument Panel J/B Assembly - Switch Assembly)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY