High Beam Headlight Circuit: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Main Body / Active Test.
5. Check that the high beam headlights illuminate.
   MAIN BODY
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Head Light Hi	High beam headlights	ON/OFF	-

   OK

   The high beam headlights illuminate.

NG → See step   2 

OK → See step   7 

1. Using a voltmeter, check the signal reading of the engine room junction block assembly. Refer to ON-VEHICLE INSPECTION .

   OK

   Output signal reading is normal

NG → See step   8 

OK: Go to next step 

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the 3D 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
   1F-5 - 3D-39	Always	Below 1 Ω
   3D-39 - 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 .
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
   3D-39 - MB-26 (DIM)	Always	Below 1 Ω

NG → See step   9 

OK: Go to next step 

1. Replace the engine room junction block assembly with a new or a known good one. Refer to REMOVAL .
2. Check that the high beam headlights operate normally.

   OK

   The high beam headlights operate normally.

NG → See step   10 

OK → END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)