Toyota Venza: Front Sensor Communication Malfunction (C1AEC)

Toyota Venza Service Manual / Park Assist / Monitoring / Intuitive Parking Assist System / Front Sensor Communication Malfunction (C1AEC)

DESCRIPTION

This DTC is stored when there is an open or short circuit in the communication line between the front sensors and the ECU, or when there is a malfunction in a front sensor.

DTC No.	DTC Detection Condition	Trouble Area
C1AEC	An open or short circuit in the communication line between the front sensors and ECU or a malfunction in a front sensor during initialization mode after the engine switch is turned on (IG).	Front ultrasonic sensor circuit Clearance warning ECU assembly

WIRING DIAGRAM

PROCEDURE

1.	CHECK DTC OUTPUT (C1AEC)

(a) Check for DTCs (See page ).

(b) Clear the DTCs (See page ).

Result	Proceed to
DTC C1AEC is output	A
No DTCs are output	B

USE SIMULATION METHOD TO CHECK

2.	CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - FRONT LEFT SENSOR)

(a) Disconnect the D79 clearance warning ECU assembly connector.

(b) Disconnect the A54 No. 1 ultrasonic sensor connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
D79-4 (BOF) - A54-1 (BI)	Always	Below 1 Ω
D79-8 (SOF) - A54-3 (SI)	Always	Below 1 Ω
D79-6 (E5) - A54-5 (EI)	Always	Below 1 Ω
D79-4 (BOF) - Body ground	Always	10 kΩ or higher
D79-8 (SOF) - Body ground	Always	10 kΩ or higher
D79-6 (E5) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK HARNESS AND CONNECTOR (FRONT LEFT SENSOR - FRONT RIGHT SENSOR)

(a) Disconnect the A55 No. 1 ultrasonic sensor connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A54-2 (BO) - A55-1 (BI)	Always	Below 1 Ω
A54-4 (SO) - A55-3 (SI)	Always	Below 1 Ω
A54-6 (EO) - A55-5 (EI)	Always	Below 1 Ω
A54-2 (BO) - Body ground	Always	10 kΩ or higher
A54-4 (SO) - Body ground	Always	10 kΩ or higher
A54-6 (EO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	INSPECT NO. 1 ULTRASONIC SENSOR (FRONT LEFT SENSOR)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 (BI) - 5 (EI)	Always	10 kΩ or higher
1 (BI) - 2 (BO)	Always	10 kΩ or higher
3 (SI) - 4 (SO)	Always	Below 1 Ω
5 (EI) - 6 (EO)	Always	Below 1 Ω

Text in Illustration

*a	Component without harness connected (No. 1 Ultrasonic Sensor (Front Left Sensor))

REPLACE NO. 1 ULTRASONIC SENSOR (FRONT LEFT SENSOR)

5.	REPLACE NO. 1 ULTRASONIC SENSOR (FRONT LEFT SENSOR)

6.	CHECK DTC OUTPUT (C1AEC)

(a) Clear the DTCs (See page ).

(b) Check for DTCs (See page ).

Result	Proceed to
DTC C1AEC is output	A
No DTCs are output	B

END

7.	REPLACE NO. 1 ULTRASONIC SENSOR (FRONT RIGHT SENSOR)

8.	CHECK DTC OUTPUT (C1AEC)

(a) Clear the DTCs (See page ).

(b) Check for DTCs (See page ).

Result	Proceed to
DTC C1AEC is output	A
No DTCs are output	B

REPLACE CLEARANCE WARNING ECU ASSEMBLY

END

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