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DTC U1233: Lost Communication With RAB Control Module

WARNING: This page is about a different variant/trim than selected.

DTC detecting condition: 

No data is received from RAB control module.

Trouble symptom: 

Coordination control of RAB control module does not operate normally.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Refer to LAN SYSTEM (DIAGNOSTICS) (HEV)>GENERAL DESCRIPTION>CAUTION .
  1. CHECK CAN COMMUNICATION HARNESS. 

    Perform the basic diagnostic procedure to check for fault in CAN communication harness. Refer to LAN SYSTEM (DIAGNOSTICS) (HEV)>BASIC DIAGNOSTIC PROCEDURE .

    Was the basic diagnostic procedure performed up to step 7?

    Yes:  Go to  2.

    No:  Perform the basic diagnostic procedure. Refer to LAN SYSTEM (DIAGNOSTICS) (HEV)>BASIC DIAGNOSTIC PROCEDURE .

  2. CHECK DTC (OTHER THAN U-CODE). 

    Check the displayed DTC.

    Is DTC other than U*** displayed? (Current malfunction)

    Yes:  Perform the diagnosis for DTCs other than the displayed U-code.

    No:  Go to  3.

  3. CHECK DTC. 

    Check the displayed DTC.

    Is DTC U1233 displayed? (Current malfunction)

    Yes:  Go to  4.

    No:  Go to  6.

  4. CHECK DTC. 
    1. Check CAN communication circuit. Refer to LAN SYSTEM (DIAGNOSTICS) (HEV)>CAN COMMUNICATION CIRCUIT CHECK .
    2. Using the Subaru Select Monitor, read all DTCs. Refer to LAN SYSTEM (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC)>OPERATION .

    Is DTC U1233 displayed? (Current malfunction)

    Yes:  Go to  5.

    No:  Go to  6.

  5. CHECK DTC. 

    Using the Subaru Select Monitor, read all DTCs. Refer to LAN SYSTEM (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC)>OPERATION .

    Is DTC U1233 detected in several modules? (Current malfunction)

    Yes:  Replace the RAB control module. Refer to REVERSE AUTOMATIC BRAKING>REVERSE AUTOMATIC BRAKING control module .

    No:  Replace the stereo camera. Refer to EYESIGHT>STEREO CAMERA .

  6. CHECK HARNESS. 
    1. Shake the harness, and check for poor contact.
    2. Using the Subaru Select Monitor, read all DTCs. Refer to LAN SYSTEM (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC)>OPERATION .

    Is DTC U1233 displayed? (Current malfunction)

    Yes:  Repair the poor contact of harness, or replace the harness.

    No:  Go to  7.

  7. CHECK CONNECTOR. 

    Check the connector used for high speed CAN for poor contact.

    Is there poor contact of connector?

    Yes:  Repair the connector that has poor contact, or replace harness.

    No:  It is possible that temporary poor communication occurs. Delete the DTC.

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