Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018WSS
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: U0235,U1104; Lost Communication with Cruise Control Front Distance Range Sensor; 2018 - 2020 MY Sienna [11/2017 -        ]

DTC

U0235

Lost Communication with Cruise Control Front Distance Range Sensor

DTC

U1104

Lost Communication with Driving Support ECU

DESCRIPTION

The driving support ECU assembly sends vehicle speed and vehicle condition information to the millimeter wave radar sensor assembly. The millimeter wave radar sensor assembly then sends information on the presence, distance, and relative speed of objects in front of the vehicle to the driving support ECU assembly. The driving support ECU assembly sends this information to the ECM and the ECM operates the dynamic radar cruise control system.

DTC No.

DTC Detection Condition

Trouble Area

MIL

U0235

While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the millimeter wave radar sensor assembly and the driving support ECU assembly is detected for approximately 1 second.

  • Millimeter wave radar sensor assembly
  • Driving support ECU assembly
  • Harness or connector

Does not come on

U1104

While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the driving support ECU assembly and the millimeter wave radar sensor assembly is detected for approximately 1 second.

  • Millimeter wave radar sensor assembly
  • Driving support ECU assembly
  • Harness or connector

Does not come on

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • When replacing the driving support ECU assembly, make sure to replace it with a new one. If a device which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle, and as a result, a DTC may be stored.
  • When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

PROCEDURE

1.

CHECK CAN COMMUNICATION SYSTEM

(a) Using the Techstream, check if the CAN communication system is functioning normally.

Click here 2018 MY Sienna [11/2017 - 08/2018]; NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM 2019 - 2020 MY Sienna [08/2018 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM

Result

Proceed to

CAN communication system DTCs are not output

OK

CAN communication system DTCs are output

NG

NG

GO TO CAN COMMUNICATION SYSTEM

OK

2.

CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - BATTERY AND BODY GROUND)

(a) Disconnect the A80 driving support ECU assembly connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A80-7 (B) - Body ground

Ignition switch ON

11 to 14 V

A80-7 (B) - Body ground

Ignition switch off

Below 1 V

Standard Resistance:

Tester Connection

Condition

Specified Condition

A80-28 (GND) - Body ground

Always

Below 1 Ω

Proceed to

OK

NG

NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

3.

CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - BATTERY AND BODY GROUND)

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

*a

Front view of wire harness connector

(to Millimeter Wave Radar Sensor Assembly)

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A77-8 (IGB) - Body ground

Ignition switch ON

11 to 14 V

A77-8 (IGB) - Body ground

Ignition switch off

Below 1 V

Standard Resistance:

Tester Connection

Condition

Specified Condition

A77-1 (SGND) - Body ground

Always

Below 1 Ω

Proceed to

OK

NG

NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

4.

CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

(a) Disconnect the A80 driving support ECU assembly connector.

(b) Disconnect the A77 millimeter wave radar sensor assembly connector.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A80-8 (CA1P) - A77-5 (CA1P)

Always

Below 1 Ω

A80-9 (CA1N) - A77-6 (CA1N)

Always

Below 1 Ω

A80-8 (CA1P) or A77-5 (CA1P) - Body ground

Always

10 kΩ or higher

A80-9 (CA1N) or A77-6 (CA1N) - Body ground

Always

10 kΩ or higher

Proceed to

OK

NG

NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

5.

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

(a) Replace the millimeter wave radar sensor assembly with a new one.

Click here 2018 - 2020 MY Sienna [11/2017 -        ]; CRUISE CONTROL: MILLIMETER WAVE RADAR SENSOR: REMOVAL

(b) Perform millimeter wave radar sensor assembly adjustment.

Click here 2018 - 2020 MY Sienna [11/2017 -        ]; CRUISE CONTROL: MILLIMETER WAVE RADAR SENSOR: ADJUSTMENT

Proceed to

NEXT

NEXT

6.

CHECK FOR DTCs (RADAR CRUISE 2)

(a) Clear the DTCs.

Click here 2018 - 2020 MY Sienna [11/2017 -        ]; CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: DTC CHECK / CLEAR

(b) Perform the following to make sure that the DTC detection conditions are met.

HINT:

If the following conditions are not met, the system cannot detect the malfunction.

  1. Turn the ignition switch to ON.
  2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON-OFF button).
  3. Drive the vehicle at 36 km/h (22 mph) or more for 1 second or more.

(c) Check for DTCs.

Click here 2018 - 2020 MY Sienna [11/2017 -        ]; CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: DTC CHECK / CLEAR

Result

Proceed to

DTC U0235 and U1104 are not output

A

DTC U0235 or U1104 is output

B

A

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

B

REPLACE DRIVING SUPPORT ECU ASSEMBLY