Headlight Beam Level Control ECU Communication Circuit: Procedure
WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (FRONT CONTROLLER - HEADLIGHT BEAM LEVEL CONTROL ECU)
- Disconnect connector 1H from the front controller.
- Disconnect the headlight beam level control ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Condition Specified Condition A21-7 - 1H-11 Always Below 1 Ω A21-7 - Body ground Always 10 kΩ or higher
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - HEADLIGHT BEAM LEVEL CONTROL ECU)
- Disconnect the headlight beam level control ECU connector and the skid control ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Condition Specified Condition A21-6 - A34-39 Always Below 1 Ω A21-5 - A34-40 Always Below 1 Ω A21-6 - Body ground Always 10 kΩ or higher A21-5 - Body ground Always 10 kΩ or higher
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (GENERATOR ASSEMBLY - HEADLIGHT BEAM LEVEL CONTROL ECU)
- Disconnect connector B6 of the generator and connector A21 of the headlight beam level control ECU.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Condition Specified Condition B6-4 (L) - A21-8 (CHG-) Always Below 1 Ω
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → PROCEED TO PROBLEM SYMPTOMS TABLE NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE