Headlight Leveling ECU Power Source Circuit: Procedure
- READ VALUE USING TECHSTREAM
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Body Electrical / HL Auto Leveling / Data List.
- Read the display on the Techstream.HL AUTO LEVELING
Tester Display Measurement Item/Range Normal Condition Diagnostic Note +B IG power supply voltage value/0 to 20 V 11 to 14 V - OK
Normal condition listed above is displayed.
NG → See step 2
OK → See step 4
- CHECK HARNESS AND CONNECTOR (AUXILIARY BATTERY - HEADLIGHT LEVELING ECU ASSEMBLY)
- Disconnect the A48 headlight leveling ECU assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A48-1 (IG) - Body ground Power switch on (IG) 11 to 14 V A48-1 (IG) - Body ground Power switch off Below 1 V
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (HEADLIGHT LEVELING ECU ASSEMBLY - BODY GROUND)
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A48-9 (E1) - Body ground Always Below 1 Ω
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 5
- Measure the resistance according to the value(s) in the table below.
- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE
- REPLACE HEADLIGHT LEVELING ECU ASSEMBLY. Refer to REMOVAL