Inspection Procedure

1. Select the ACTIVE TEST, use the intelligent tester to generate a control command, and then check that the headlight assembly (low) illuminates.

   Multiplex network body ECU 

   ACTIVE TEST DETAIL - MULTIPLEX NETWORK BODY ECU
   
   

   Item	Test Details	Diagnostic Note
   HEAD LIGHT	Headlight relay ON / OFF	-

   OK: 

   Headlight assembly (low) illuminates. 

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

NG: Go to next step 

1. Remove the H-LP L LWR fuse from the engine room No. 2 relay block.
2. Remove the H-LP R LWR fuse from the engine room No. 2 relay block.
3. Measure the resistance of the fuses.

   Standard resistance: 

   Below 1 Ω 

NG: REPLACE FUSE 

OK: Go to next step 

1. Remove the HEAD LP relay from the engine room No. 1 relay block.
2. Measure the resistance of the HEAD LP relay.

   Standard resistance 

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (When battery voltage is applied to terminals 1 and 2)

Fig 1: Inspecting Head LP Relay

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE HEAD LP RELAY 

OK: Go to next step 

1. Disconnect the DL junction block connector.
2. Measure the voltage of the wire harness side connector.

   Standard voltage 

   VOLTAGE SPECIFICATION
   
   

   Tester Connection	Specified Condition
   SYSTEM DESCRIPTION	10 to 14 V

Fig 2: Checking Wire Harness (Cowl Side Junction Block RH - Battery)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

1. Check the wire harness between the headlight (Low LH) and battery, and the headlight (Low LH) and body ground.
   1. Disconnect the B11 light connector.
   2. Turn the light control switch to the ON (HEAD) position.
   3. Measure the voltage and resistance of the wire harness side connector.

      Standard voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Specified Condition
      B11-17 (LO) - Body ground	10 to 14 V

      Standard resistance 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Specified Condition
      B11-16 (E) - Body ground	Below 1 Ω

   Fig 3: Checking Wire Harness Between Headlight (Low LH) And Battery, And Headlight (Low LH) And Body Ground

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the wire harness between the headlight (Low RH) and battery, and the headlight (Low RH) and body ground.
   1. Disconnect the B2 light connector.
   2. Turn the light control switch to the ON (HEAD) position.
   3. Measure the voltage and resistance of the wire harness side connector.

      Standard voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      B2-17 (LO) - Body ground	Engine switch on (IG)	10 to 14 V

      Standard resistance 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Specified Condition
      B2-16 (E) - Body ground	Below 1 Ω

Fig 4: Checking Wire Harness Between Headlight (Low RH) And Battery, And Headlight (Low RH) And Body Ground

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: REPLACE HEADLIGHT ASSEMBLY (LOW LH OR LOW RH) 

NG: Go to next step 

1. Check the harness and the connectors between the headlight (Low LH or Low RH) and the HEAD LP relay.
   1. Disconnect the B11 light connector.
   2. Remove the HEAD LP relay from the engine room No. 1 relay block.
   3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open) 

      RESISTANCE SPECIFICATION
      
      

      Headlight Assembly	Tester Connection	Specified Condition
      LH	B11-17 (LO) - HEAD LP relay terminal (5)	Below 1 Ω
      RH	B2-17 (LO) - HEAD LP relay terminal (5)	Below 1 Ω

      Standard resistance (Check for short) 

      RESISTANCE SPECIFICATION
      
      

      Headlight Assembly	Tester Connection	Specified Condition
      LH	B11-17 (LO) or HEAD LP relay terminal (5) - Body ground	10 kΩ or higher
      RH	B2-17 (LO) or HEAD LP relay terminal (5) - Body ground	10 kΩ or higher

Fig 5: Checking Wire Harness (Headlight (Low LH Or Low RH) - Head LP Relay)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

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