Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Front Camera Feedback Malfunction (C1681)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Audio & Visual & Telematics / Park Assist / Monitoring / Panoramic View Monitor System / Front Camera Feedback Malfunction (C1681)

DESCRIPTION

DTC C1681 is stored if the parking assist ECU judges as a result of its self check that a synchronization problem is occurring in the image signal sent from the front television camera assembly to the parking assist ECU.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1681

Front Camera Feedback Malfunction

Front television camera power supply failure
  • Harness or connector
  • Front television camera assembly
  • Parking assist ECU

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When "!" is displayed on the multi-display assembly after the cable is disconnected from the negative (-) battery terminal, correct the steering angle neutral point.

    Click here

  • Depending on the parts that are replaced or operations that are performed during vehicle inspection or maintenance, calibration of other systems as well as panoramic view monitor system may be needed.

    Click here

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (PARKING ASSIST ECU - FRONT TELEVISION CAMERA ASSEMBLY)

(a) Disconnect the J158 parking assist ECU connector.

(b) Disconnect the p1 front television camera assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J158-15 (BCB+) - p1-6 (BCB+)

Always

Below 1 Ω

J158-36 (BCV+) - p1-3 (BCV+)

Always

Below 1 Ω

J158-13 (BCV-) - p1-2 (BCV-)

Always

Below 1 Ω

J158-37 (BGND) - p1-5 (BGND)

Always

Below 1 Ω

J158-14 (SGND) - Body ground

Always

Below 1 Ω

J158-15 (BCB+) or p1-6 (BCB+) - Body ground

Always

10 kΩ or higher

J158-36 (BCV+) or p1-3 (BCV+) - Body ground

Always

10 kΩ or higher

J158-13 (BCV-) or p1-2 (BCV-) - Body ground

Always

10 kΩ or higher

J158-37 (BGND) or p1-5 (BGND) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

CHECK PARKING ASSIST ECU (BCV-, BGND)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J158-37 (BGND) - Body ground

Always

Below 1 Ω

J158-13 (BCV-) - Body ground

Always

Below 1 Ω

*a

Component without harness connected

(Parking Assist ECU)
NG

REPLACE PARKING ASSIST ECU

OK

3.

CHECK PARKING ASSIST ECU (BCB+, BGND)

(a) Connect the J158 parking assist ECU connector.

*a

Component with harness connected

(Parking Assist ECU)

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

J158-15 (BCB+) - J158-37 (BGND)

Engine switch on (IG)

5.5 to 7.05 V
NG

REPLACE PARKING ASSIST ECU

OK

4.

CHECK FRONT TELEVISION CAMERA ASSEMBLY (BCV+, BGND)

(a) Connect the p1 front television camera assembly connector.

(b) Using an oscilloscope, check the waveform of the front television camera assembly.

HINT:

A waterproof connector is used for the front television camera assembly. Therefore, inspect the waveform at the parking assist ECU with the connector connected.

*a

Component with harness connected

(Parking Assist ECU)

*b

Waveform 1

*c

Waveform 2

*d

Synchronization Signal

*e

Video Waveform

-

-
Measurement Condition

Item

Content

Terminal No. (Symbol)

J158-36 (BCV+) - J158-37 (BGND)

Tool Setting

200 mV/DIV., 50 μs./DIV.

Condition
  • Waveform 1: Engine switch on (IG), panoramic view monitor main switch (integration control and panel assembly) on, camera lens not covered, displaying image
  • Waveform 2: Engine switch on (IG), panoramic view monitor main switch (integration control and panel assembly) on, camera lens covered, blacking out screen

HINT:

  • The video waveform changes according to the image sent by the front television camera assembly.
  • The video waveform is constantly output when the engine switch is on (ACC).

OK:

Waveform is similar to that shown in the illustration.

OK

REPLACE PARKING ASSIST ECU

NG

REPLACE FRONT TELEVISION CAMERA ASSEMBLY

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