Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Lost Communication with Cruise Control Module Missing Message (U010487)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Engine & Hybrid System / Cruise Control / Front Radar Sensor System / Lost Communication with Cruise Control Module Missing Message (U010487)

DESCRIPTION

The millimeter wave radar sensor assembly communicates with the forward recognition camera via CAN communication.

If a communication error is detected between the forward recognition camera and millimeter wave radar sensor assembly, the millimeter wave radar sensor assembly stores this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

U010487

Lost Communication with Cruise Control Module Missing Message
  • Engine switch on (IG)
  • Communication malfunction with the forward recognition camera is detected
  • 10 seconds or more
  • CAN bus line
  • Forward recognition camera
  • Millimeter wave radar sensor assembly

Pattern

DTC output part name

(Display on Techstream)

Suspected Area (Malfunction Status)

Millimeter Wave Radar Sensor Assembly

(Front Radar Sensor)

Forward Recognition Camera

(Pre-Collision System)

U010487

U023587
○: DTC is output

-: DTC is not output

Pattern 1

○

○
  • Open in CAN communication line (forward recognition camera - CAN junction connector)
  • Open in CAN communication line (millimeter wave radar sensor assembly - CAN junction connector)
  • CAN junction connector disconnected
  • CAN junction connector
  • Short in CAN communication line
  • Open or short in forward recognition camera internal circuit
  • Open or short in millimeter wave radar sensor assembly internal circuit

Pattern 2

○

-
  • Forward recognition camera connector disconnected
  • Forward recognition camera power supply circuit malfunction
  • Forward recognition camera internal malfunction
  • Millimeter wave radar sensor assembly internal malfunction

HINT:

If the DTCs are output simultaneously, the inspection area can be narrowed down.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

    Click here

  • When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle and a DTC may be stored.
  • When the millimeter wave radar sensor assembly has been replaced with a new one, it is necessary to perform millimeter wave radar sensor assembly adjustment and front radar acceleration sensor calibration, and to clear the vehicle control history.

    Click here

  • When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle and a DTC may be stored.
  • If the forward recognition camera has been replaced with a new one, forward recognition camera adjustment must be performed.

    HINT:

    Forward recognition camera adjustment can be performed by using either One Time Recognition or Sequential Recognition.

    One Time Recognition: Click here

    Sequential Recognition: Click here

PROCEDURE

1.

CHECK FOR DTCs

(a) Check for pre-collision system DTCs.

Body Electrical > Pre-Collision System > Trouble Codes

Result

Proceed to

DTC U023587 is output

A

DTC U023587 is not output

B
B

GO TO STEP 5

A

2.

CHECK CAN BUS LINES (NO. 1 CAN JUNCTION CONNECTOR)

*1

DLC3

-

-

*a

Front view of wire harness connector

(to No. 1 CAN Junction Connector)

*b

to Millimeter Wave Radar Sensor Assembly

*c

to Forward Recognition Camera

-

-

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the A86 No. 1 CAN junction connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A86-1 - A86-12

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

A86-5 - A86-16

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A86-1 - J141-4(CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

A86-12 - J141-4(CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

A86-1 - J141-16(BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

A86-12 - J141-16(BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

A86-5 - J141-4(CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

A86-16 - J141-4(CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

A86-5 - J141-16(BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

A86-16 - J141-16(BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

(e) Connect the A86 No. 1 CAN junction connector.

Result

Proceed to

OK

A

NG (Connected to: Forward Recognition Camera)

B

NG (Connected to: Millimeter Wave Radar Sensor Assembly)

C
A

REPLACE NO. 1 CAN JUNCTION CONNECTOR
C

GO TO STEP 4

B

3.

CHECK CAN BUS LINES (FORWARD RECOGNITION CAMERA - NO. 1 CAN JUNCTION CONNECTOR)

*1

DLC3

-

-

*a

Front view of wire harness connector

(to Forward Recognition Camera)

-

-

(a) Disconnect the U14 forward recognition camera connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

U14-6 (CANH) - U14-12 (CANL)

Cable disconnected from negative (-) battery terminal

108 to 132Ω

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

U14-6 (CANH) - J141-4 (CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

U14-12 (CANL) - J141-4 (CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

U14-6 (CANH) - J141-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

U14-12 (CANL) - J141-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

(d) Connect the U14 forward recognition camera connector.

OK

REPLACE FORWARD RECOGNITION CAMERA

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (FORWARD RECOGNITION CAMERA - NO. 1 CAN JUNCTION CONNECTOR)

4.

CHECK CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 1 CAN JUNCTION CONNECTOR)

*1

DLC3

-

-

*a

Front view of wire harness connector

(to Millimeter Wave Radar Sensor Assembly)

-

-

(a) Disconnect the A70 millimeter wave radar sensor assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A70-5 (CA1P) - A70-6 (CA1N)

Cable disconnected from negative (-) battery terminal

108 to 132Ω

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A70-5 (CA1P) - J141-4 (CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

A70-6 (CA1N) - J141-4 (CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

A70-5 (CA1P) - J141-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

A70-6 (CA1N) - J141-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

(d) Connect the A70 millimeter wave radar sensor assembly connector.

OK

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 1 CAN JUNCTION CONNECTOR)

5.

CHECK CONNECTOR (FORWARD RECOGNITION CAMERA)

(a) Check the locking part and terminals of the forward recognition camera connector.

NOTICE:

  • Make sure the connector is not loose or disconnected.
  • Make sure that the connector and terminals are not deformed or corroded.

OK:

The connector and terminals are normal.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (FORWARD RECOGNITION CAMERA)
OK

6.

CHECK HARNESS AND CONNECTOR (FORWARD RECOGNITION CAMERA POWER SOURCE CIRCUIT)

*a

Front view of wire harness connector

(to Forward Recognition Camera)

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the U14 forward recognition camera connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

U14-10 (GND) - Body ground

Always

Below 1 Ω

(d) Connect the cable to the negative (-) battery terminal.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

U14-7 (IGB) - Body ground

Engine switch on (IG)

11 to 14 V

(f) Connect the U14 forward recognition camera connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

7.

INSPECT FORWARD RECOGNITION CAMERA (WAVEFORM)

*a

Front view of wire harness connector

(to No. 1 CAN Junction Connector)

*b

Waveform

*c

to Forward Recognition Camera

-

-

(a) Turn the engine switch off.

(b) Disconnect the A86 No. 1 CAN junction connector.

(c) Turn the engine switch on (IG).

(d) Using an oscilloscope, measure the waveform at the A86 No. 1 CAN junction connector.

Measurement Condition:

Tester Connection

Condition

Tool Setting

A86-1 - Body ground

Engine switch on (IG)

1 V/DIV., 100 μs/DIV.

NOTICE:

The oscilloscope waveform is for reference only and does not include noise, fluctuations, etc.

OK:

A waveform similar to that in the illustration can be observed.

(e) Connect the A86 No. 1 CAN junction connector.

OK

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

NG

REPLACE FORWARD RECOGNITION CAMERA

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