DESCRIPTION
The main body ECU (multiplex network body ECU) controls the low beam headlights.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Click here
PROCEDURE
1. | PERFORM ACTIVE TEST USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Main Body / Active Test.
(e) Perform the Active Test according to the display on the Techstream.
Body Electrical > Main Body > Active Test Tester Display | Measurement Item | Control Range | Diagnostic Note |
---|---|---|---|
Headlight Relay | Low beam headlights | OFF/ON | - |
Tester Display |
---|
Headlight Relay |
OK:
Low beam headlights illuminate.
OK | ![]() | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
2. | INSPECT SEMICONDUCTOR POWER INTEGRATION ECU |
(a) Remove the semiconductor power integration ECU from the engine room relay block and junction block assembly.
Click here
(b) Inspect the semiconductor power integration ECU.
Click here
OK:
Semiconductor power integration ECU is normal.
NG | ![]() | REPLACE SEMICONDUCTOR POWER INTEGRATION ECU |
|
3. | CHECK HARNESS AND CONNECTOR (POWER SOURCE - SEMICONDUCTOR POWER INTEGRATION ECU) |
(a) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection | Condition | Specified Condition |
---|---|---|
B-1 (BATT) - Body ground | Always | 11 to 14 V |
NG | ![]() | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
4. | CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR POWER INTEGRATION ECU - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) |
(a) Disconnect the 2C instrument panel junction block assembly connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
---|---|---|
1D-8 - 2C-31 | Always | Below 1 Ω |
1D-8 or 2C-31 - Body ground | Always | 10 kΩ or higher |
NG | ![]() | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
5. | INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY |
*a | Component without harness connected (Instrument Panel Junction Block Assembly) | - | - |
(a) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
Click here
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
---|---|---|
2C-31 - MB-15 (HRLY) | Always | Below 1 Ω |
OK | ![]() | REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) |
NG | ![]() | REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY |
Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Telematics System: Lost Communication with Body Control Module Missing Message (U014087,U015587,U016387)
DESCRIPTION These DTCs are stored when a malfunction occurs in the CAN communication circuit. DTC No. Detection Item DTC Detection Condition Trouble Area U014087 Lost Communication with Body Control Module Missing Message CAN reception error CAN communication system U015587 ...
Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Airbag System: Curtain Shield Airbag Sensor (RH) (B1630,B1632)
DESCRIPTION The side collision sensor RH circuit (bus 1) consists of the airbag sensor assembly, door side airbag sensor RH and rear airbag sensor RH. The door side airbag sensor RH and rear airbag sensor RH detect impacts to the vehicle and send signals to the airbag sensor assembly to determine if ...