LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2017 >> RAV4 LE, AWD >> Repair and Diagnosis (Single Page) >> Steering >> Steering Control Systems >> Lane Departure Alert System (W/ Steering Control) - Diagnostic Codes & Circuit Tests - (Except Hybrid) >> LANE DEPARTURE ALERT SYSTEM (W/ Steering Control) >> DTC C1A72: Communication Error from FCM to Driving Support ECU [10/2015 - ] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC C1A72: Communication Error from FCM to Driving Support ECU [10/2015 - ]: Procedure

  1. CHECK DTC OUTPUT 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Enter the following menus: Chassis / LKA/LDA / Trouble Codes.
    5. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2015 - ]

      Chassis > LKA/LDA > Clear DTCs 

    6. Make sure that the DTC detection conditions are met.

      HINT: 

      If the following procedure is not performed, the previously output DTC cannot be detected.

      1. Turn the ignition switch is turned ON and wait 7 seconds or more.
    7. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2015 - ]

      Chassis > LKA/LDA > Trouble Codes 

      Result

      Result Proceed to
      DTC C1A72 is output A
      DTC C1A72 is not output B

    Result: 

    USE SIMULATION METHOD TO CHECK:  HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - 08/2016]  ,  HOW TO PROCEED WITH TROUBLESHOOTING [08/2016 - 08/2017]  ,  HOW TO PROCEED WITH TROUBLESHOOTING [08/2017 - ] 

    Result: 

    See step  2

  2. REPLACE FORWARD RECOGNITION CAMERA 
    1. Replace the forward recognition camera.

      Refer to REMOVAL [10/2015 - ]

    2. Adjust the forward recognition camera.

      Refer to ADJUSTMENT [10/2015 - ]

    Result: 

    NEXT 

    See step  3

  3. CHECK DTC OUTPUT 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Enter the following menus: Chassis / LKA/LDA / Trouble Codes.
    5. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2015 - ]

      Chassis > LKA/LDA > Clear DTCs 

    6. Make sure that the DTC detection conditions are met.

      HINT: 

      If the following procedure is not performed, the previously output DTC cannot be detected.

      1. Turn the ignition switch is turned ON and wait 7 seconds or more.
    7. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2015 - ]

      Chassis > LKA/LDA > Trouble Codes 

      Result

      Result Proceed to
      DTC C1A72 is output A
      DTC C1A72 is not output B

    Result: 

    REPLACE DRIVING SUPPORT ECU ASSEMBLY:  REMOVAL [10/2015 - ] 

    Result: 

    END (FORWARD RECOGNITION CAMERA WAS DEFECTIVE)