PRE-COLLISION: PRE-COLLISION SYSTEM: C1A0A; Front Radar Sensor Region Code Mismatch; 2018 - 2020 MY Sienna [11/2017

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM1000000018YBF
Model Year Start: 2018	Model: Sienna	Prod Date Range: [11/2017 - ]
Title: PRE-COLLISION: PRE-COLLISION SYSTEM: C1A0A; Front Radar Sensor Region Code Mismatch; 2018 - 2020 MY Sienna [11/2017 - ]

DTC

C1A0A

Front Radar Sensor Region Code Mismatch

DESCRIPTION

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect objects in front of the vehicle.

Based on signals from the millimeter wave radar sensor assembly, the driving support ECU assembly calculates the possibility of a collision and operates the pre-collision system if it determines that the possibility is high.

When the millimeter wave radar sensor assembly is replaced with a new one, it acquires the country specification information from the driving support ECU assembly. Also, when the driving support ECU assembly is replaced with a new one, it receives country specification information from the main body ECU (multiplex network body ECU). If country specification information in the millimeter wave radar sensor assembly, driving support ECU assembly and/or main body ECU do not match, DTC C1A0A will be stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1A0A	Front Radar Sensor Region Code Mismatch	When the ignition switch is ON, the country specification information in the driving support ECU assembly and millimeter wave radar sensor assembly do not match for approximately 2 seconds.	Millimeter wave radar sensor assembly Driving support ECU assembly

CAUTION / NOTICE / HINT

NOTICE:

When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly 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. As a result, a DTC may be stored.
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. 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.
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The pre-collision system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.
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PROCEDURE

1.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

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(b) Perform the following procedure.

HINT:

If the following procedure is not performed, the previously output DTC cannot be detected.

Turn the ignition switch to ON and wait 2 seconds or more.

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Result	Proceed to
DTC C1A0A is not output	A
DTC C1A0A is output	B

USE SIMULATION METHOD TO CHECK

2.	REPLACE DRIVING SUPPORT ECU ASSEMBLY

(a) Replace the driving support ECU assembly.

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3.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

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(b) Perform the following procedure.

HINT:

If the following procedure is not performed, the previously output DTC cannot be detected.

Turn the ignition switch to ON and wait 2 seconds or more.

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Result	Proceed to
DTC C1A0A is not output	A
DTC C1A0A is output	B

END (DRIVING SUPPORT ECU ASSEMBLY WAS DEFECTIVE)

4.	REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

(a) Replace the millimeter wave radar sensor assembly.

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(b) Adjust the millimeter wave radar sensor assembly.

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END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)