Lexus ES: Front Sensor Communication Malfunction (C1AEC)

Lexus ES (XZ10) Service Manual / Audio & Visual & Telematics / Park Assist / Monitoring / Parking Support Alert System (for Gasoline Model) / 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.	Detection Item	DTC Detection Condition	Trouble Area
C1AEC	Front Sensor Communication Malfunction	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 Harness or connector Clearance warning ECU assembly

WIRING DIAGRAM

PROCEDURE

1.	INITIALIZE FRONT CENTER ULTRASONIC SENSOR AND FRONT CORNER ULTRASONIC SENSOR

(a) Initialize the front center ultrasonic sensor and front corner ultrasonic sensor.

Click here

2.	CHECK DTC OUTPUT (C1AEC)

(a) Check for DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

(b) Clear the DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

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

USE SIMULATION METHOD TO CHECK

3.	CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - FRONT CORNER ULTRASONIC SENSOR RH)

(a) Disconnect the N41 clearance warning ECU assembly connector.

(b) Disconnect the B1 front corner ultrasonic sensor RH.

Standard Resistance:

Tester Connection	Condition	Specified Condition
N41-4 (BOF) - B1-4 (BI)	Always	Below 1 Ω
N41-8 (SOF) - B1-5 (SI)	Always	Below 1 Ω
N41-6 (E5) - B1-6 (EI)	Always	Below 1 Ω
N41-4 (BOF) or B1-4 (BI) - Body ground	Always	10 kΩ or higher
N41-8 (SOF) or B1-5 (SI) - Body ground	Always	10 kΩ or higher
N41-6 (E5) or B1-6 (EI) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	CHECK HARNESS AND CONNECTOR (FRONT CORNER ULTRASONIC SENSOR RH - FRONT CENTER ULTRASONIC SENSOR RH)

(a) Disconnect the B2 front center ultrasonic sensor RH.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
B1-1 (BO) - B2-4 (BI)	Always	Below 1 Ω
B1-2 (SO) - B2-5 (SI)	Always	Below 1 Ω
B1-3 (EO) - B2-6 (EI)	Always	Below 1 Ω
B1-1 (BO) or B2-4 (BI) - Body ground	Always	10 kΩ or higher
B1-2 (SO) or B2-5 (SI) - Body ground	Always	10 kΩ or higher
B1-3 (EO) or B2-6 (EI) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK HARNESS AND CONNECTOR (FRONT CENTER ULTRASONIC SENSOR RH - FRONT CENTER ULTRASONIC SENSOR LH)

(a) Disconnect the B3 front center ultrasonic sensor LH.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
B2-1 (BO) - B3-4 (BI)	Always	Below 1 Ω
B2-2 (SO) - B3-5 (SI)	Always	Below 1 Ω
B2-3 (EO) - B3-6 (EI)	Always	Below 1 Ω
B2-1 (BO) or B3-4 (BI) - Body ground	Always	10 kΩ or higher
B2-2 (SO) or B3-5 (SI) - Body ground	Always	10 kΩ or higher
B2-3 (EO) or B3-6 (EI) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (FRONT CENTER ULTRASONIC SENSOR LH - FRONT CORNER ULTRASONIC SENSOR LH)

(a) Disconnect the B4 front corner ultrasonic sensor LH.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
B3-1 (BO) - B4-4 (BI)	Always	Below 1 Ω
B3-2 (SO) - B4-5 (SI)	Always	Below 1 Ω
B3-3 (EO) - B4-6 (EI)	Always	Below 1 Ω
B3-1 (BO) or B4-4 (BI) - Body ground	Always	10 kΩ or higher
B3-2 (SO) or B4-5 (SI) - Body ground	Always	10 kΩ or higher
B3-3 (EO) or B4-6 (EI) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	INSPECT FRONT CORNER ULTRASONIC SENSOR RH

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
4 (BI) - 6 (EI)	Always	10 kΩ or higher
4 (BI) - 1 (BO)	Always	Below 1 Ω
5 (SI) - 2 (SO)	Always	Below 30 Ω
6 (EI) - 3 (EO)	Always	Below 1 Ω

*a	Component without harness connected (Front Corner Ultrasonic Sensor RH)

REPLACE FRONT CORNER ULTRASONIC SENSOR RH

8.	INSPECT FRONT CENTER ULTRASONIC SENSOR RH

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
4 (BI) - 6 (EI)	Always	10 kΩ or higher
4 (BI) - 1 (BO)	Always	Below 1 Ω
5 (SI) - 2 (SO)	Always	Below 30 Ω
6 (EI) - 3 (EO)	Always	Below 1 Ω

*a	Component without harness connected (Front Center Ultrasonic Sensor RH)

REPLACE FRONT CENTER ULTRASONIC SENSOR RH

9.	INSPECT FRONT CENTER ULTRASONIC SENSOR LH

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
4 (BI) - 6 (EI)	Always	10 kΩ or higher
4 (BI) - 1 (BO)	Always	Below 1 Ω
5 (SI) - 2 (SO)	Always	Below 30 Ω
6 (EI) - 3 (EO)	Always	Below 1 Ω

*a	Component without harness connected (Front Center Ultrasonic Sensor LH)

REPLACE FRONT CENTER ULTRASONIC SENSOR LH

10.	INSPECT FRONT CORNER ULTRASONIC SENSOR LH

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
4 (BI) - 6 (EI)	Always	10 kΩ or higher
4 (BI) - 1	Always	Below 1 Ω
5 (SI) - 2	Always	Below 30 Ω
6 (EI) - 3	Always	Below 1 Ω

*a	Component without harness connected (Front Corner Ultrasonic Sensor LH)

REPLACE FRONT CORNER ULTRASONIC SENSOR LH

11.	REPLACE FRONT CORNER ULTRASONIC SENSOR RH

Click here

12.	CHECK DTC OUTPUT (C1AEC)

(a) Clear the DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs

(b) Check for DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

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

END (FRONT CORNER ULTRASONIC SENSOR RH WAS DEFECTIVE)

13.	REPLACE FRONT CENTER ULTRASONIC SENSOR RH

Click here

14.	CHECK DTC OUTPUT (C1AEC)

(a) Clear the DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs

(b) Check for DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

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

END (FRONT CENTER ULTRASONIC SENSOR RH WAS DEFECTIVE)

15.	REPLACE FRONT CENTER ULTRASONIC SENSOR LH

Click here

16.	CHECK DTC OUTPUT (C1AEC)

(a) Clear the DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs

(b) Check for DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

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

END (FRONT CENTER ULTRASONIC SENSOR LH WAS DEFECTIVE)

17.	REPLACE FRONT CORNER ULTRASONIC SENSOR LH

Click here

18.	CHECK DTC OUTPUT (C1AEC)

(a) Clear the DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs

(b) Check for DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

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

REPLACE CLEARANCE WARNING ECU ASSEMBLY

END (FRONT CORNER ULTRASONIC SENSOR LH WAS DEFECTIVE)

SEE MORE:

A25a-fks Oil And Oil Filter

Components COMPONENTS ILLUSTRATION *1 CENTER NO. 4 ENGINE UNDER COVER - - ILLUSTRATION *1 OIL FILTER SUB-ASSEMBLY *2 OIL FILLER CAP SUB-ASSEMBLY *3 GASKET

INSTALLATION PROCEDURE 1. INSTALL FUEL MAIN VALVE ASSEMBLY (a) Apply gasoline to 2 new O-rings. Then install the O-rings to the fuel main valve assembly (for Low Pressure). (b) Apply gasoline to 2 new O-rings. Then install the O-rings to the fuel main valve assembly (for High Pressure). (c) Install

Lexus ES: Front Sensor Communication Malfunction (C1AEC)

READ NEXT:

Rear Sensor Communication Malfunction (C1AED)

Fr Sensor Initialization Incomplete (C1AF3)

Rr Sensor Initialization Incomplete (C1AF4)

SEE MORE:

A25a-fks Oil And Oil Filter

Installation