DTC    C1AEC    Front Sensor Communication Malfunction

for Preparation Click here


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 power switch is turned on (IG).
  1. Front ultrasonic sensor circuit
  2. Clearance warning ECU

WIRING DIAGRAM


E149953E24


INSPECTION PROCEDURE

1.CHECK DTC OUTPUT (C1AEC)

  1. Check for DTCs (Click here).

  1. Clear the DTCs (Click here).

  1. Recheck for DTCs (Click here).

    Result:
    Result
    		Proceed to
    DTC C1AEC is output
    		A
    No DTC is output
    		B



B
USE SIMULATION METHOD TO CHECK (Click here)
A


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

  1. Disconnect the A49 connector from the clearance warning ECU.

  1. Disconnect the C3 connector from the No. 1 ultrasonic sensor.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A49-9 (BOF) - C3-1 (BI)
    		Always
    		Below 1 Ω
    A49-8 (SOF) - C3-3 (SI)
    A49-24 (E5) - C3-5 (EI)
    A49-9 (BOF) - Body ground
    		10 kΩ or higher
    A49-8 (SOF) - Body ground
    A49-24 (E5) - Body ground



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

  1. Disconnect the C3 and C4 connectors from the No. 1 ultrasonic sensors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    C3-2 (BO) - C4-1 (BI)
    		Always
    		Below 1 Ω
    C3-4 (SO) - C4-3 (SI)
    C3-6 (EO) - C4-5 (EI)
    C3-2 (BO) - Body ground
    		10 kΩ or higher
    C3-4 (SO) - Body ground
    C3-6 (EO) - Body ground



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

  1. Remove the No. 1 ultrasonic sensor (front left sensor) (Click here).



    E221362E01

  1. 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)
    3 (SI) - 4 (SO)
    		Below 1 Ω
    5 (EI) - 6 (EO)

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



NG
REPLACE NO. 1 ULTRASONIC SENSOR (FRONT LEFT SENSOR) (Click here)
OK


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

  1. Replace the No. 1 ultrasonic sensor (front left sensor) with a known good one (Click here).

    HINT:
    All of the sensors are interchangeable. To confirm whether a sensor is functioning normally, switch it with a known good sensor from the other end of the vehicle.


NEXT


6.CHECK DTC OUTPUT (C1AEC)

  1. Clear the DTCs (Click here).

  1. Check for DTCs (Click here).

    Result:
    Result
    		Proceed to
    DTC C1AEC is output
    		A
    No DTC is output
    		B



B
END (FRONT LEFT SENSOR WAS DEFECTIVE)
A


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

  1. Replace the No. 1 ultrasonic sensor (front right sensor) with a known good one (Click here).

    HINT:
    All of the sensors are interchangeable. To confirm whether a sensor is functioning normally, switch it with a known good sensor from the other end of the vehicle.


NEXT


8.CHECK DTC OUTPUT (C1AEC)

  1. Clear the DTCs (Click here).

  1. Check for DTCs (Click here).

    Result:
    Result
    		Proceed to
    DTC C1AEC is output
    		A
    No DTC is output
    		B



B
END (FRONT RIGHT SENSOR WAS DEFECTIVE)
A

REPLACE CLEARANCE WARNING ECU ASSEMBLY (Click here)