Headlight Beam Level Control ECU Communication Circuit: Procedure

1. Disconnect the A43 headlight beam level control ECU connector.
   Fig 1: Identifying A43 Headlight Beam Level Control & A30 Cowl Side Junction Block ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the A30 cowl side junction block ECU connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance

   Tester Connection	Specified Condition
   A43-8 (CHG-) - A30-13 (ALTL)	Below 1 Ω
   A43-26 (WNG) - A30-14 (WNG)	Below 1 Ω
   A43-8 (CHG-) or A30-13 (ALTL) - Body ground	10 kΩ or higher
   A43-26 (WNG) or A30-14 (WNG) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

1. Check the wire harness between the headlight beam level control ECU and skid control ECU (2GR-FSE).
   Fig 2: Identifying A43 Headlight Beam Level Control ECU Connector And A58 Skid Control ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Disconnect the A43 headlight beam level control ECU connector.
   2. Disconnect the A58 skid control ECU connector.
   3. Measure the resistance of the wire harness side connectors.

      Standard resistance

      Tester Connection	Specified Condition
      A43-6 (SPDR) - A58-5 (FRO)	Below 1 Ω
      A43-5 (SPDL) - A58-4 (FLO)	Below 1 Ω
      A43-6 (SPDR) or A58-5 (FRO) - Body ground	10 kΩ or higher
      A43-5 (SPDL) or A58-4 (FLO) - Body ground	10 kΩ or higher

2. Check the wire harness between the headlight beam level control ECU and skid control ECU (1UR-FSE).
   Fig 3: Identifying A43 Headlight Beam Level And A13 And A15 Skid Control ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Disconnect the A43 headlight beam level control ECU connector.
   2. Disconnect the A13 and A15 skid control ECU connectors.
   3. Measure the resistance of the wire harness side connectors.

      Standard resistance

      Tester Connection	Specified Condition
      A43-6 (SPDR) - A13-10 (FRO)	Below 1 Ω
      A43-5 (SPDL) - A15-10 (FLO)	Below 1 Ω
      A43-6 (SPDR) or A13-10 (FRO) - Body ground	10 kΩ or higher
      A43-5 (SPDL) or A15-10 (FLO) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS AND CONNECTOR 

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