LEXUS PARKING ASSIST-SENSOR SYSTEM, Diagnostic DTC:C1AEC

DTC Code DTC Name
C1AEC Front Sensor Communication Malfunction

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).

  • Front ultrasonic sensor circuit

  • Clearance warning ECU*1

  • Parking assist ECU*2

WIRING DIAGRAM

A01NHD0E02

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK DTC OUTPUT (C1AEC)


    1. Check for DTCs Click here.

    2. Clear the DTCs Click here.

    3. Recheck for DTCs Click here.

      Result
      Result Proceed to

      DTC C1AEC is output

      (w/o Parking Assist Monitor System)

      		 A

      DTC C1AEC is output

      (w/ Parking Assist Monitor System)

      		 B
      No DTC is output C

    B

    CHECK HARNESS AND CONNECTOR (PARKING ASSIST ECU - FRONT LEFT SENSOR) Click here

    C

    USE SIMULATION METHOD TO CHECK Click here

    A

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


    1. A01NF46E12
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Clearance Warning ECU)
      *2

      Front view of wire harness connector

      (to No. 1 Ultrasonic Sensor (Front Left Sensor))

      Disconnect the F52 connector from the clearance warning ECU.

    2. Disconnect the A12 connector from the No. 1 ultrasonic sensor.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F52-21 (BOF) - A12-1 (BI) Always Below 1 Ω
      F52-9 (SOF) - A12-3 (SI)
      F52-19 (E1) - A12-5 (EI)
      F52-21 (BOF) - Body ground 10 kΩ or higher
      F52-9 (SOF) - Body ground
      F52-19 (E1) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A01NGOLE16
      Text in Illustration
      *1

      Front view of wire harness connector

      (to No. 1 Ultrasonic Sensor (Front Left Sensor))
      *2

      Front view of wire harness connector

      (to No. 1 Ultrasonic Sensor (Front Right Sensor))

      Disconnect the A12 and A13 connectors from the No. 1 ultrasonic sensors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A12-2 (BO) - A13-1 (BI) Always Below 1 Ω
      A12-4 (SO) - A13-3 (SI)
      A12-6 (EO) - A13-5 (EI)
      A12-2 (BO) - Body ground 10 kΩ or higher
      A12-4 (SO) - Body ground
      A12-6 (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.

    2. A01NEYFE13
      Text in Illustration
      *1

      Component without harness connected

      (No. 1 Ultrasonic Sensor (Front Left Sensor))

      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

    NG

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

    OK

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


    1. A01NHV1E07
      Text in Illustration
      *1

      No. 1 Ultrasonic Sensor

      (Front Left Sensor)

      Replace the No. 1 ultrasonic sensor (front left sensor) with a normally functioning sensor Click here.

      Tech Tips

      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.

    2. 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. A01NHV1E07
      Text in Illustration
      *1

      No. 1 Ultrasonic Sensor

      (Front Right Sensor)

      Replace the No. 1 ultrasonic sensor (front right sensor) with a normally functioning sensor Click here.

      Tech Tips

      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.

    2. 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 Click here

  9. CHECK HARNESS AND CONNECTOR (PARKING ASSIST ECU - FRONT LEFT SENSOR)


    1. A01NDLYE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Parking Assist ECU)
      *2

      Front view of wire harness connector

      (to No. 1 Ultrasonic Sensor (Front Left Sensor))

      Disconnect the F55 connector from the parking assist ECU.

    2. Disconnect the A12 connector from the No. 1 ultrasonic sensor.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F55-1 (CSB1) - A12-1 (BI) Always Below 1 Ω
      F55-3 (LIN1) - A12-3 (SI)
      F55-2 (CSG1) - A12-5 (EI)
      F55-1 (CSB1) - Body ground 10 kΩ or higher
      F55-3 (LIN1) - Body ground
      F55-2 (CSG1) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A01NGOLE17
      Text in Illustration
      *1

      Front view of wire harness connector

      (to No. 1 Ultrasonic Sensor (Front Left Sensor))
      *2

      Front view of wire harness connector

      (to No. 1 Ultrasonic Sensor (Front Right Sensor))

      Disconnect the A12 and A13 connectors from the No. 1 ultrasonic sensors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A12-2 (BO) - A13-1 (BI) Always Below 1 Ω
      A12-4 (SO) - A13-3 (SI)
      A12-6 (EO) - A13-5 (EI)
      A12-2 (BO) - Body ground 10 kΩ or higher
      A12-4 (SO) - Body ground
      A12-6 (EO) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


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

    2. A01NEYFE14
      Text in Illustration
      *1

      Component without harness connected

      (No. 1 Ultrasonic Sensor (Front Left Sensor))

      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

    NG

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

    OK

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


    1. A01NHV1E07
      Text in Illustration
      *1

      No. 1 Ultrasonic Sensor

      (Front Left Sensor)

      Replace the No. 1 ultrasonic sensor (front left sensor) with a normally functioning sensor Click here.

      Tech Tips

      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

  13. CHECK DTC OUTPUT (C1AEC)


    1. Clear the DTCs Click here.

    2. 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

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


    1. A01NHV1E07
      Text in Illustration
      *1

      No. 1 Ultrasonic Sensor

      (Front Right Sensor)

      Replace the No. 1 ultrasonic sensor (front right sensor) with a normally functioning sensor Click here.

      Tech Tips

      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

  15. CHECK DTC OUTPUT (C1AEC)


    1. Clear the DTCs Click here.

    2. 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 PARKING ASSIST ECU Click here