2021 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE

Inspection Mode 9

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.
DTC Description & trouble part Note
B2680 HIGH BEAM ASSIST SENSOR BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
B2681 HIGH BEAM ASSIST CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
B2682 HIGH BEAM ASSIST UNIT FIELD OF VIEW BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
B2683 VEHICLE SPECIFICATION INFORMATION REGISTRATION BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U0101 LOST COMMUNICATION WITH TCM BIU detects DTC only when [MT/AT Setting] is [AT].
U0128 LOST COMMUNICATION WITH PARK BRAKE CONTROL MODULE BIU detects DTC only when [EPB setting] is [Support].
U0164 LOST COMMUNICATION WITH HVAC CONTROL MODULE BIU detects DTC only when [Auto A/C ECU Setting] is [Support].
U0169 LOST COMMUNICATION WITH SUNROOF CONTROL MODULE BIU detects DTC only when [Sunroof setting] is [Support].
U0222 LOST COMMUNICATION WITH DRIVER'S DOOR POWER WINDOW BIU detects DTC only when [P/W ECU Setting] is [Driver Seat], [Driver/Passenger Seat] or [Four Seat].
U0223 LOST COMMUNICATION WITH PASSENGER'S DOOR POWER WINDOW BIU detects DTC only when [P/W ECU Setting] is [Driver/Passenger Seat] or [Four Seat].
U0224 LOST COMMUNICATION WITH RR DOOR POWER WINDOW BIU detects DTC only when [P/W ECU Setting] is [Four Seat].
U0225 LOST COMMUNICATION WITH RL DOOR POWER WINDOW BIU detects DTC only when [P/W ECU Setting] is [Four Seat].
U0402 INVALID DATA RECEIVED FROM TCM BIU detects DTC only when [MT/AT Setting] is [AT].
U0417 INVALID DATA RECEIVED FROM PARK BRAKE CONTROL MODULE BIU detects DTC only when [EPB setting] is [Support].
U0424 INVALID DATA RECEIVED FROM HVAC CONTROL MODULE BIU detects DTC only when [Auto A/C ECU Setting] is [Support].
U111F <HBA>LOST COMMUNICATION WITH VEHICLE DYNAMICS CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U1145 <HBA>LOST COMMUNICATION WITH BODY CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U115A <HBA>LOST COMMUNICATION WITH INSTRUMENT PANEL CLUSTER (IPC) CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U123C LOST COMMUNICATION WITH HIGH BEAM ASSIST CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U141A <HBA>INVALID DATA RECEIVED FROM VEHICLE DYNAMICS CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U142A <HBA>INVALID DATA RECEIVED FROM INSTRUMENT PANEL CLUSTER (IPC) CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U1446 <HBA>INVALID DATA RECEIVED FROM BODY CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U153D INVALID DATA RECEIVED FROM HIGH BEAM ASSIST CONTROL MODULE BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [mirror HBA].
U1283 LOST COMMUNICATION WITH EYESIGHT SA-BUS BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [EyeSight HBA] or the vehicle is equipped with EyeSight.
U1584 INVALID DATA RECEIVED FROM EYESIGHT SA-BUS BIU detects DTC only when [High Beam Assist Function Setting (mirror/EyeSight)] is [EyeSight HBA] or the vehicle is equipped with EyeSight.
U1673 LIN COMMUNICATION BUS ERROR BODY CONTROL MODULE BIU detects DTC only when [Sunroof setting] is [Support].
U1674 LIN COMMUNICATION BUS 2 ERROR BODY CONTROL MODULE BIU detects DTC only when [P/W ECU Setting] is [Driver Seat], [Driver/Passenger Seat] or [Four Seat].
U1822 LOST COMMUNICATION WITH MASTER MAIN SWITCH BIU detects DTC only when [P/W ECU Setting] is [Driver Seat], [Driver/Passenger Seat] or [Four Seat].

Diagnostic procedure: 

  1. Using the Subaru Select Monitor, perform the clear memory of [Body Control]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY
  2. Using the Subaru Select Monitor, read the DTC of [Body Control] to check that there is no DTC displayed. Ref. to BODY CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) 
    NOTE:

    If the DTC is displayed on the screen, the trouble is still present. Perform the diagnosis for the displayed DTCs. After solving the DTC, repeat from step   1 . 

  3. Confirm that [Customize] items of [Body Control] correspond to the vehicle. Ref. to BODY CONTROL (DIAGNOSTICS)>CUSTOMIZE 
  4. Turn the ignition switch OFF → ON, and wait for 10 seconds or more.
  5. Using the Subaru Select Monitor, read the DTC of [Body Control] to check that there is no DTC displayed. Ref. to BODY CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) 
    NOTE:

    If the DTC is displayed on the screen, the trouble is still present. Perform the diagnosis for the displayed DTCs. 

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.