SUBARU Rear Vehicle Detection On/Off Display Cannot Be Switched In The Advanced Equipment Screen

WARNING: This page is about a different car, the 2021 Subaru Ascent. However, it is still accessible from the selected car via links, so may be relevant.

Detecting condition:

Communication circuit, radar sensor or MFD is abnormal.

Wiring diagram:

Multi-function display (MFD) system Ref. to WIRING SYSTEM>Multi-function Display (MFD) System>WIRING DIAGRAM .
CAN communication system Ref. to WIRING SYSTEM>CAN Communication System>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to MULTI-FUNCTION DISPLAY (DIAGNOSTICS)>General Description>CAUTION .

CHECK IGNITION POWER SUPPLY CIRCUIT .
1. Turn the ignition switch to OFF.
2. Disconnect the MFD connector.
3. Turn the ignition switch to ON.
4. Using a tester, measure the voltage between the MFD connector and chassis ground.
Connector & terminal

(i122) No. 23 (+) - Chassis ground (-):

Is the voltage 10 V or more?

Yes : Repair or replace the open circuit of harness. (Check battery as well as fuse.)

No : Go to 2.
CHECK LAN SYSTEM .
Perform the diagnosis for LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>Basic Diagnostic Procedure>PROCEDURE .

Is the check result OK?

Yes : Go to 3.

No : Perform the inspection according to the diagnosis for LAN system.
CHECK SUBARU REAR VEHICLE DETECTION .
Using the Subaru Select Monitor, read the DTCs of [Blind Spot Detection/Rear Cross Traffic Alert (RH)] or [Blind Spot Detection/Rear Cross Traffic Alert (LH)]. Ref. to Blind Spot Detection/Rear Cross Traffic Alert (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Are any DTCs displayed? (Current malfunction)

Yes : Perform the diagnosis according to displayed DTC. Ref. to Blind Spot Detection/Rear Cross Traffic Alert (DIAGNOSTICS)>Diagnostic Trouble Code (DTC)>LIST .

No : Replace the MFD. Ref. to INSTRUMENTATION/DRIVER INFO>MULTI-FUNCTION DISPLAY (MFD) .