PRE-COLLISION: PRE-COLLISION SYSTEM: C1A46; Yaw Rate Sensor; 2018 - 2020 MY Sienna [11/2017

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM1000000018YBI
Model Year Start: 2018	Model: Sienna	Prod Date Range: [11/2017 - ]
Title: PRE-COLLISION: PRE-COLLISION SYSTEM: C1A46; Yaw Rate Sensor; 2018 - 2020 MY Sienna [11/2017 - ]

DTC

C1A46

Yaw Rate Sensor

DESCRIPTION

The driving support ECU assembly receives yaw rate sensor signals from the yaw rate sensor (airbag sensor assembly) and skid control ECU (brake actuator assembly) via CAN communication. If the driving support ECU assembly receives a yaw rate sensor malfunction signal from the yaw rate sensor (airbag sensor assembly) or skid control ECU (brake actuator assembly), DTC C1A46 will be stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1A46	Yaw Rate Sensor	While the vehicle is being driven at a speed of 5 km/h (4 mph) or more, the driving support ECU assembly receives a yaw rate sensor malfunction signal from yaw rate sensor for approximately 10 seconds. While the vehicle is being driven at a speed of 5 km/h (4 mph) or more, the driving support ECU assembly receives a yaw rate sensor zero point malfunction signal from skid control ECU (brake actuator assembly) for approximately 10 seconds.	Vehicle stability control system Yaw rate sensor (Airbag sensor assembly) Skid control ECU (Brake actuator 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.
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.
Click here

PROCEDURE

1.	CHECK FOR DTCs (VEHICLE STABILITY CONTROL SYSTEM)

HINT:

Pre-collision system DTC C1A46 may be stored due to a malfunction in the vehicle stability control system. Therefore, it is necessary to check for and troubleshoot vehicle stability control system DTCs first.

(a) Check for DTCs.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
Vehicle stability control system DTCs are not output	A
Vehicle stability control system DTCs are output	B

GO TO VEHICLE STABILITY CONTROL SYSTEM

2.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

Click here

(b) Perform the following procedure.

HINT:

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

Drive the vehicle at a speed of 5 km/h (4 mph) or more for 10 seconds or more.

Click here

Result	Proceed to
DTC C1A46 is not output	A
DTC C1A46 is output	B

USE SIMULATION METHOD TO CHECK

3.	REPLACE DRIVING SUPPORT ECU ASSEMBLY

(a) Replace the driving support ECU assembly.

Click here

4.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

Click here

(b) Perform the following procedure.

HINT:

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

Drive the vehicle at a speed of 5 km/h (4 mph) or more for 10 seconds or more.

Click here

Result	Proceed to
DTC C1A46 is not output	A
DTC C1A46 is output	B

END (DRIVING SUPPORT ECU ASSEMBLY WAS DEFECTIVE)

5.	REPLACE YAW RATE SENSOR (AIRBAG SENSOR ASSEMBLY)

(a) Replace the yaw rate sensor (airbag sensor assembly).

Click here

6.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

Click here

(b) Perform the following procedure.

HINT:

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

Drive the vehicle at a speed of 5 km/h (4 mph) or more for 10 seconds or more.

Click here

Result	Proceed to
DTC C1A46 is not output	A
DTC C1A46 is output	B

END (YAW RATE SENSOR WAS DEFECTIVE)

REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU)