Toyota Venza: Lost Communication with AFS LIN (B124D)

Toyota Venza Service Manual / Lighting (ext) / Lighting System / Lost Communication with AFS LIN (B124D)

DESCRIPTION

The DTC is stored when the main body ECU (driver side junction block assembly) detects malfunctions in the LIN communication system.

DTC No.	DTC Detection Condition	Trouble Area
B124D	Malfunction in LIN communication system	Inner rear view mirror assembly Harness or connector AFS ECU (headlight swivel ECU assembly)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

First perform the communication function inspections in How to Proceed with Troubleshooting to confirm that there are no CAN communication malfunctions before troubleshooting this symptom.

PROCEDURE

1.	CHECK FOR DTC

(a) Clear the DTCs (See page ).

(b) Check for DTCs (See page ).

OK:

DTC B124D is not output.

USE SIMULATION METHOD TO CHECK

2.	CHECK HARNESS AND CONNECTOR (AFS ECU - INNER REAR VIEW MIRROR ASSEMBLY)

(a) Disconnect the D44 AFS ECU (headlight swivel ECU assembly) connector.

(b) Disconnect the P12 inner rear view mirror assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
D44-10 (SMR) - P12-3 (LIN)	Always	Below 1 Ω
P12-3 (LIN) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	INSPECT AFS ECU (HEADLIGHT SWIVEL ECU ASSEMBLY)

(a) Reconnect the D44 AFS ECU (headlight swivel ECU assembly) connector.

(b) Connect an oscilloscope to the P12 inner rear view mirror assembly connector.

OK:

Tester Connection	Tool Setting	Condition	Specified Condition
P12-3 (LIN) - P12-2 (E)	2 V/DIV., 20 ms./DIV.	Ignition switch ON	Correct waveform is as shown

Text in Illustration

*1	Front view of wire harness connector (to Inner Rear View Mirror Assembly)

REPLACE INNER REAR VIEW MIRROR ASSEMBLY

REPLACE AFS ECU (HEADLIGHT SWIVEL ECU ASSEMBLY)

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