TOYOTA 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 Code 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).

  • No. 1 ultrasonic sensor (front side)

  • Harness or connector

  • Parking assist ECU*1

  • Clearance warning ECU assembly*2

WIRING DIAGRAM

A0157FSE01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC C1AEC is output (w/ Side Monitor System) A
      DTC C1AEC is output (w/o Side Monitor System) B
      DTC C1AEC is not output C

    B

    CHECK HARNESS AND CONNECTOR (NO. 1 ULTRASONIC SENSOR [FL SENSOR] - CLEARANCE WARNING ECU ASSEMBLY) Click here

    C

    USE SIMULATION METHOD TO CHECK Click here

    A

  2. CHECK HARNESS AND CONNECTOR (NO. 1 ULTRASONIC SENSOR [FL SENSOR] - PARKING ASSIST ECU)


    1. Disconnect the B8 No. 1 ultrasonic sensor (FL sensor) connector.

    2. Disconnect the F76 parking assist ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B8-1 (BI) - F76-5 (CSB1) Always Below 1 Ω
      B8-3 (SI) - F76-23 (LIN1) Always Below 1 Ω
      B8-5 (EI) - F76-6 (CSG1) Always Below 1 Ω
      B8-1 (BI) - Body ground Always 10 kΩ or higher
      B8-3 (SI) - Body ground Always 10 kΩ or higher
      B8-5 (EI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 1 ULTRASONIC SENSOR [FL SENSOR] - NO. 1 ULTRASONIC SENSOR [FR SENSOR])


    1. Disconnect the B8 No. 1 ultrasonic sensor (FL sensor) connector.

    2. Disconnect the B7 No. 1 ultrasonic sensor (FR sensor) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B8-2 (BO) - B7-1 (BI) Always Below 1 Ω
      B8-4 (SO) - B7-3 (SI) Always Below 1 Ω
      B8-6 (EO) - B7-5 (EI) Always Below 1 Ω
      B8-2 (BO) - Body ground Always 10 kΩ or higher
      B8-4 (SO) - Body ground Always 10 kΩ or higher
      B8-6 (EO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK PARKING ASSIST ECU


    1. A015E7BE15
      Text in Illustration
      *a

      Component with harness connected

      (Parking Assist ECU)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F76-5 (CSB1) - Body ground Engine switch on (IG) 7.2 to 8.8 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F76-6 (CSG1) - Body ground Always Below 1 Ω

    NG

    REPLACE PARKING ASSIST ECU Click here

    OK

  5. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC C1AEC is not output.

    NG

    REPLACE NO. 1 ULTRASONIC SENSOR (FL SENSOR) Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  6. REPLACE NO. 1 ULTRASONIC SENSOR (FL SENSOR)


    1. Replace the No. 1 ultrasonic sensor (FL sensor) with a normally functioning one Click here.


    NEXT

  7. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC C1AEC is not output.

    NG

    REPLACE NO. 1 ULTRASONIC SENSOR (FR SENSOR) Click here

    OK

    END (NO. 1 ULTRASONIC SENSOR [FL SENSOR] IS DEFECTIVE)

  8. REPLACE NO. 1 ULTRASONIC SENSOR (FR SENSOR)


    1. Replace the No. 1 ultrasonic sensor (FR sensor) with a normally functioning one Click here


    NEXT

  9. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC C1AEC is not output.

    NG

    REPLACE PARKING ASSIST ECU Click here

    OK

    END (NO. 1 ULTRASONIC SENSOR [FR SENSOR] IS DEFECTIVE)

  10. CHECK HARNESS AND CONNECTOR (NO. 1 ULTRASONIC SENSOR [FL SENSOR] - CLEARANCE WARNING ECU ASSEMBLY)


    1. Disconnect the B8 No. 1 ultrasonic sensor [FL sensor] connector.

    2. Disconnect the F12 clearance warning ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B8-1 (BI) - F12-21 (CSB1) Always Below 1 Ω
      B8-3 (SI) - F12-9 (LIN1) Always Below 1 Ω
      B8-5 (EI) - F12-19 (CSG1) Always Below 1 Ω
      B8-1 (BI) - Body ground Always 10 kΩ or higher
      B8-3 (SI) - Body ground Always 10 kΩ or higher
      B8-5 (EI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK HARNESS AND CONNECTOR (NO. 1 ULTRASONIC SENSOR [FL SENSOR] - NO. 1 ULTRASONIC SENSOR [FR SENSOR])


    1. Disconnect the B8 No. 1 ultrasonic sensor (FL sensor) connector.

    2. Disconnect the B7 No. 1 ultrasonic sensor (FR sensor) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B8-2 (BO) - B7-1 (BI) Always Below 1 Ω
      B8-4 (SO) - B7-3 (SI) Always Below 1 Ω
      B8-6 (EO) - B7-5 (EI) Always Below 1 Ω
      B8-2 (BO) - Body ground Always 10 kΩ or higher
      B8-4 (SO) - Body ground Always 10 kΩ or higher
      B8-6 (EO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK CLEARANCE WARNING ECU ASSEMBLY


    1. A015DQUE14
      Text in Illustration
      *a

      Component with harness connected

      (Clearance Warning ECU Assembly)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F12-21 (CSB1) - Body ground Engine switch on (IG) 7.2 to 8.8 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F12-19 (CSG1) - Body ground Always Below 1 Ω

    NG

    REPLACE CLEARANCE WARNING ECU ASSEMBLY Click here

    OK

  13. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC C1AEC is not output.

    NG

    CHECK PARKING ASSIST ECU Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  14. REPLACE NO. 1 ULTRASONIC SENSOR (FL SENSOR)


    1. Replace the No. 1 ultrasonic sensor (FL sensor) with a normally functioning one Click here.


    NEXT

  15. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC C1AEC is not output.

    NG

    REPLACE NO. 1 ULTRASONIC SENSOR (FR SENSOR) Click here

    OK

    END (NO. 1 ULTRASONIC SENSOR [FL SENSOR] IS DEFECTIVE)

  16. REPLACE NO. 1 ULTRASONIC SENSOR (FR SENSOR)


    1. Replace the No. 1 ultrasonic sensor (FR sensor) with a normally functioning one Click here.


    NEXT

  17. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC C1AEC is not output.

    NG

    REPLACE CLEARANCE WARNING ECU ASSEMBLY Click here

    OK

    END (NO. 1 ULTRASONIC SENSOR [FR SENSOR] IS DEFECTIVE)