Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001CUSZ
Model Year Start: 2019 Model: GR Corolla Prod Date Range: [06/2018 - 01/2019]
Title: PRE-COLLISION: PRE-COLLISION SYSTEM (for Gasoline Model): U023587; Lost Communication with Cruise Control Front Distance Range Sensor Missing Message; 2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019]

DTC

U023587

Lost Communication with Cruise Control Front Distance Range Sensor Missing Message

DESCRIPTION

The forward recognition camera and millimeter wave radar sensor assembly communicate via CAN communication. If a signal is not received from the millimeter wave radar sensor assembly, the forward recognition camera stores a DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

U023587

Lost Communication with Cruise Control Front Distance Range Sensor Missing Message

3 seconds or more after the engine switch is turned on (IG), a communication malfunction with the millimeter wave radar sensor assembly is detected for 2 seconds or more.

  • CAN bus line
  • Forward recognition camera
  • Millimeter wave radar sensor assembly

Pattern

DTC Location Name

(Techstream Displayed Name)

Suspected Area (Malfunction Status)

Forward recognition camera

(Pre-Collision System)

Millimeter wave radar sensor assembly

(Front Radar Sensor)

U023587

U010487

○: DTC is stored

-: DTC is not stored

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

-

  • Millimeter wave radar sensor assembly connector disconnected
  • Millimeter wave radar sensor assembly power supply circuit malfunction
  • Millimeter wave radar sensor assembly internal malfunction
  • Forward recognition camera 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 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION

  • 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 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; CRUISE CONTROL: MILLIMETER WAVE RADAR SENSOR: ADJUSTMENT

  • 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.
  • When the forward recognition camera has been replaced with a new one or the windshield glass has been removed and installed, it is necessary to perform forward recognition camera adjustment and to clear the vehicle control history.

    HINT:

    Forward recognition camera adjustment can be performed by using either One Time Recognition or Sequential Recognition. When clearing vehicle control history, refer to the following links:

    One Time Recognition: Click here 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; CRUISE CONTROL: FRONT CAMERA: ADJUSTMENT (ONE TIME RECOGNITION)

    Sequential Recognition: Click here 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; CRUISE CONTROL: FRONT CAMERA: ADJUSTMENT (SEQUENTIAL RECOGNITION)

PROCEDURE

1.

CHECK FOR DTCs

(a) Using the Techstream, check for front radar sensor system DTCs.

Body Electrical > Front Radar Sensor > Trouble Codes

Result

Proceed to

DTC U010487 is output

A

DTC U010487 is not output

B

B

GO TO STEP 5

A

2.

CHECK CAN BUS LINES (NO. 2 CAN JUNCTION CONNECTOR)

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

(b) Disconnect the I108 No. 2 CAN junction connector.

*1

DLC3

-

-

*a

Front view of wire harness connector

(to No. 2 CAN Junction Connector)

*b

to Forward Recognition Camera

*c

to Millimeter Wave Radar Sensor Assembly

-

-

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Connected to

I108-6 - I108-17

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

Forward Recognition Camera

I108-4 - I108-15

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

Millimeter Wave Radar Sensor Assembly

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Connected to

I108-6 - I26-4(CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

Forward Recognition Camera

I108-17 - I26-4(CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

I108-6 - I26-16(BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

I108-17 - I26-16(BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

I108-4 - I26-4(CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

Millimeter Wave Radar Sensor Assembly

I108-15 - I26-4(CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

I108-4 - I26-16(BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

I108-15 - I26-16(BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

(e) Connect the I108 No. 2 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. 2 CAN JUNCTION CONNECTOR

C

GO TO STEP 4

B

3.

CHECK CAN BUS LINES (FORWARD RECOGNITION CAMERA - NO. 2 CAN JUNCTION CONNECTOR)

(a) Disconnect the T9 forward recognition camera connector.

*1

DLC3

-

-

*a

Front view of wire harness connector

(to Forward Recognition Camera)

-

-

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

T9-6 (CANH) - T9-12 (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

T9-6 (CANH) - I26-4 (CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

T9-12 (CANL) - I26-4 (CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

T9-6 (CANH) - I26-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

T9-12 (CANL) - I26-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

(d) Connect the T9 forward recognition camera connector.

OK

REPLACE FORWARD RECOGNITION CAMERA

NG

REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (FORWARD RECOGNITION CAMERA - NO. 2 CAN JUNCTION CONNECTOR)

4.

CHECK CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 2 CAN JUNCTION CONNECTOR)

(a) Disconnect the A1 millimeter wave radar sensor assembly connector.

*1

DLC3

-

-

*a

Front view of wire harness connector

(to Millimeter Wave Radar Sensor Assembly)

-

-

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A1-5 (CA1P) - A1-6 (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

A1-5 (CA1P) - I26-4 (CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

A1-6 (CA1N) - I26-4 (CG)

Cable disconnected from negative (-) battery terminal

200 Ω or higher

A1-5 (CA1P) - I26-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

A1-6 (CA1N) - I26-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

(d) Connect the A1 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. 2 CAN JUNCTION CONNECTOR)

5.

CHECK CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

(a) Check the locking part and terminals of the millimeter wave radar sensor assembly connector.

NOTICE:

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

OK:

The connector and terminals are normal.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

OK

6.

CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

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

(b) Disconnect the A1 millimeter wave radar sensor assembly connector.

*a

Front view of wire harness connector

(to Millimeter Wave Radar Sensor Assembly)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A1-1 (SGND) - 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

A1-8 (IGB) - Body ground

Engine switch ON

11 to 14 V

(f) Connect the A1 millimeter wave radar sensor assembly connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY POWER SOURCE CIRCUIT)

OK

7.

INSPECT MILLIMETER WAVE RADAR SENSOR ASSEMBLY (WAVEFORM)

(a) Turn the engine switch off.

(b) Disconnect the I108 No. 2 CAN junction connector.

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

(d) Using an oscilloscope, measure the waveform at I108 No. 2 CAN junction connector.

*a

Front view of wire harness connector

(to No. 2 CAN Junction Connector)

*b

Waveform

*c

to Millimeter Wave Radar Sensor Assembly

-

-

Measurement Condition:

Tester Connection

Condition

Tool Setting

I108-4 - 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 I108 No. 2 CAN junction connector.

OK

REPLACE FORWARD RECOGNITION CAMERA

NG

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY