Low Beam Headlight Circuit [11/2016 - ]: 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. Perform the Active Test according to the display on the Techstream.

   Body Electrical > Main Body > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Headlight Relay	Headlight relay (Low beam headlights)	OFF or ON	-

   Body Electrical > Main Body > Active Test 

   Tester Display
   Headlight Relay

   OK

   Headlight relay operates. (Low beam headlights illuminate.)

   Result

   Proceed to
   OK
   NG

Result:  1

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [11/2016 - ] 

Result:  2

NG 

See step  2

1. Remove the semiconductor pwr integration ECU from the No. 1 engine room relay block and No. 1 junction block assembly.

   Refer to REMOVAL [12/2013 - ]

2. Inspect the semiconductor pwr integration ECU.

   Refer to INSPECTION [12/2013 - ]

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPLACE SEMICONDUCTOR PWR INTEGRATION ECU. Refer to  REMOVAL [12/2013 - ] 

Result:  1

OK 

See step  3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   2B-1 (BATT) - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result:  1

OK 

See step  4

1. Disconnect the 4F 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
   1D-8 (HLLS) - 4F-27	Always	Below 1 Ω
   1D-8 (HLLS) or 4F-27 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result:  1

OK 

See step  5

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the instrument panel junction block assembly.

   Refer to REMOVAL [12/2013 - ]

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
   4F-27 - MB-15 (HRLY)	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result:  1

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [12/2013 - ] 

Result:  2

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [12/2013 - ]