DTC U1446: <HBA>Invalid Data Received From Body Control Module

DTC detecting condition: 

Defective data was transmitted from body integrated unit.

Trouble symptom: 

HBA does not operate normally.

1. CHECK CAN COMMUNICATION HARNESS.

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

   Was the basic diagnostic procedure performed up to step 7?

   Yes: Go to  2.

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

2. CHECK DTC (OTHER THAN U-CODE).

   Check the displayed DTC.

   Are DTCs other than U*** displayed?

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

   No: Go to  3.

3. CHECK DTC (U-CODE).

   Check the displayed DTC.

   Is DTC for the bus off or the data no-receive displayed?

   Yes: Perform the diagnosis for DTCs for the displayed bus off or the data no-receive.

   No: Go to  4.

4. CHECK DTC (CURRENT MALFUNCTION).

   Check the displayed DTC.

   Is U1446 a current malfunction?

   Yes: Go to  5.

   No: Go to  7.

5. CHECK DTC (CURRENT MALFUNCTION).
   1. Turn the ignition switch to OFF.
   2. Disconnect the body integrated unit connector.
   3. Connect the disconnected connectors.
   4. Read the DTC using Subaru Select Monitor. Ref. to LAN SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Is U1446 a current malfunction?

   Yes: Go to  6.

   No: Go to  7.

6. CHECK DTC.

   Using the Subaru Select Monitor, read DTC of all the systems. Ref. to LAN SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Is U1446 detected in the body integrated unit?

   Yes: Replace the body integrated unit. Ref. to SECURITY AND LOCKS>BODY INTEGRATED UNIT .

   No: Replace the module that the DTC has been detected.

7. CHECK HARNESS.
   1. Shake the harness, and check for poor contact.
   2. Using the Subaru Select Monitor, read DTC of CAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Is U1446 a current malfunction?

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

   No: Go to  8.

8. 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.