Low Beam Headlight Circuit [12/2014 - ]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Main Body / Active Test.
5. Perform the Active Test according to the display on the Techstream.
   MAIN BODY
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Headlight Relay	Headlight relay (low beam headlights)	ON/OFF	-

   OK

   Headlight relay operates. (Low beam headlights illuminate.)

NG → See step   2 

OK → See step   7 

1. Remove the H-LP relay from the No. 2 engine room relay block and No. 2 junction block assembly.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	Voltage not applied between terminals 1 and 2	10 kΩ or higher
   3 - 5	Voltage applied between terminals 1 and 2	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (H-LP Relay)

NG → REPLACE H-LP RELAY 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Relay terminal 1 - Body ground	Ignition switch off	11 to 14 V
   Relay terminal 5 - Body ground	Ignition switch off	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the A67 headlight assembly LH connector.
2. Disconnect the A66 headlight assembly RH connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Relay terminal 3 - A67-4 (LO)	Always	Below 1 Ω
   Relay terminal 3 - A66-4 (LO)	Always	Below 1 Ω
   Relay terminal 3 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the 3C instrument panel junction block assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Relay terminal 2 - 3C-18	Always	Below 1 Ω
   Relay terminal 2 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the instrument panel junction block assembly. Refer to REMOVAL [12/2014 - ] .

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3C-18 - MB-15 (HRLY)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Instrument Panel Junction Block Assembly)

NG → See step   9 

OK → See step   8