Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Automatic High Beam System (B124B)
DESCRIPTION
The main body ECU (multiplex network body ECU) determines the status of the automatic high beam system based on the automatic high beam system signal from the forward recognition camera.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | DTC Output from |
|---|---|---|---|---|
| B124B | Automatic High Beam System | Malfunction in automatic high beam system |
| Main Body |
- *: w/ Road Sign Assist System
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
-
The lighting system uses the CAN communication system. Inspect the communication functions by following How to Proceed with Troubleshooting. Troubleshoot the automatic high beam system after confirming that the communication systems are functioning properly.
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-
Before replacing the main body ECU (multiplex network body ECU), refer to Registration.
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HINT:
If the forward recognition camera stores a DTC for a malfunction of any of the following, this DTC will be stored simultaneously.- Speed sensor
- Yaw rate sensor
- Millimeter wave radar sensor
- CAN communication system
PROCEDURE
| 1. | CHECK FOR DTC (HEALTH CHECK) |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: System Select / Health Check.
(e) Check for DTCs.
| Result | Proceed to |
|---|---|
| Only DTC B124B is output | A |
| DTC B124B and other DTCs are output | B |
| B | .gif) | GO TO OTHER DTC CHART |
|
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| 2. | CHECK FRONT CAMERA SYSTEM |
(a) Check if a dynamic radar cruise control system, lane control system, road sign assist system* or pre-collision system warning message is displayed on the multi-information display.
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OK:
No dynamic radar cruise control system, lane control system, road sign assist system* or pre-collision system warning messages are displayed.
- *: w/ Road Sign Assist System
| OK | | REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) |
| NG | | GO TO FRONT CAMERA SYSTEM |
Vehicle Control History
VEHICLE CONTROL HISTORY CHECK VEHICLE CONTROL HISTORY HINT:
The vehicle control history data stores the history of the reject function and system protection operations.
The number of occurrences, ...
Light Sensor Circuit (B1244)
DESCRIPTION The automatic light control sensor detects ambient light. The sensor creates an electrical signal based on the amount of light detected, and sends the signal to the main body ECU (multiple ...
Other materials:
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Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Lighting System (w/ Automatic Headlight Beam Level Control System): Headlight LH Circuit (B2439,B243A)
DESCRIPTION The No. 1 headlight ECU sub-assembly LH and No. 1 headlight ECU sub-assembly RH internally boost the power supply voltage to ensure a constant supplied current for the lo/hi beam LED of their respective headlight. By monitoring the LED power supply voltage, abnormal current and malfuncti ...
Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual
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Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual
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