Low Beam Headlight Circuit [07/2014 - ]: Procedure

1. Confirm vehicle type.
   RESULT
   
   

   Result	Proceed to
   for DRL Bulb Type	A
   for DRL LED Type	B

B → See step   8 

A: Go to next step 

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. According to the display on the Techstream, perform the Active Test.
   MAIN BODY
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Headlight Relay	Running light relay	OFF or ON	-

   OK

   Running light relay operates. (Low beam headlights illuminate.)

NG → See step   3 

OK → See step   14 

1. Check the operation of the high beam headlights.

   OK

   High beam headlights operate normally.

NG → See step   16 

OK: Go to next step 

1. Remove the running light relay from the No. 2 engine room relay block.
2. Connect the positive (+) lead from the battery to terminal 6 (+B).

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

3. Connect the negative (-) lead from the battery to terminal 4 (H) and 3 (E).
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   1 (HLOR) - Battery negative terminal	Always	11 to 14 V
   5 (HLOL) - Battery negative terminal	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Running Light Relay)

NG → See step   13 

OK: Go to next step 

1. Remove the running light relay from the No. 2 engine room relay block.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   DRL-6 (+B) - Body ground	Always	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   DRL-3 (E) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	No. 2 Engine Room Relay Block
   *2	Running Light Relay Terminal

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the running light relay from the No. 2 engine room relay block assembly.
2. Disconnect the 3C instrument panel junction block assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   DRL-4 (H) - 3C-18	Always	Below 1 Ω
   DRL-4 (H) or 3C-18 - 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 [07/2014 - ] .
2. Remove the main body ECU from the instrument panel junction block assembly. Refer to REMOVAL [07/2014 - ] .
3. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   TEXT IN ILLUSTRATION
   
   

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

   Standard Resistance

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

NG → REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

OK → See step   15 

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. According to the display on the Techstream, perform the Active Test.
   MAIN BODY
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Headlight Relay	Headlight relay	OFF or ON	-

   OK

   Headlight relay operates (Low beam headlights illuminate).

NG → See step   9 

OK → PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 

1. Inspect the headlight relay (H-LP/US-DRL relay). Refer to ON-VEHICLE INSPECTION [07/2014 - ] .

NG → REPLACE HEADLIGHT RELAY (H-LP RELAY) 

OK: Go to next step 

1. Remove the headlight relay (H-LP/US-DRL relay) from the No. 2 engine room relay block.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   H-LP/US-DRL-1 - Body ground	Always	11 to 14 V
   H-LP/US-DRL-3 - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *1	No. 2 Engine Room Relay Block
   *2	Headlight Relay (H-LP/US-DRL Relay) Holder

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the headlight relay (H-LP/US-DRL relay) from the No. 2 engine room relay block.
2. Disconnect the 3C instrument panel junction block assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H-LP/US-DRL- 2 - 3C-18	Always	Below 1 Ω
   H-LP/US-DRL- 2 or 3C-18 - 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.
2. Remove the main body ECU from the instrument panel junction block assembly.
3. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   TEXT IN ILLUSTRATION
   
   

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

   Standard Resistance

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

NG → REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

OK → REPLACE MAIN BODY ECU