Keyless Access Lock/Unlock Cannot Be Performed From Any Of The Doors

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.

Trouble causes:

Malfunction of exterior antenna, touch sensor, lock/unlock button
Malfunction of access key, access key battery
Malfunction of door lock control system
Malfunction of keyless access control module power supply circuit
Keyless access control module malfunction

Wiring diagram:

Keyless access with push button start system Ref. to WIRING SYSTEM>KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

CAUTION:

Check that there are no other registered access keys inside the vehicle.
Inspect LAN system according to the basic diagnostic procedure, and make sure that there is no fault.
Check that the keyless access function is not stopped.
When the access key or keyless access control module is replaced, registration of the immobilizer is required. For the relevant procedures, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.
Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION

CHECK OPERATION OF KEYLESS DOOR LOCK .
Using the keyless function of the access key, check the operation of the door lock.

Does it lock/unlock normally?

Yes : Check the exterior antenna, touch sensor, lock/unlock button. Ref. to SECURITY AND LOCKS>KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM>INSPECTION

No : Go to 2.
CHECK ACCESS KEY .
Check for whether lock and unlock is possible with the registered access key.

Is there any access key which can lock/unlock when the touch sensor is operated?

Yes : Check the access key that does not operate. Go to 3.

No : Go to 4.
CHECK ACCESS KEY .
Check the battery of the access key. Ref. to SECURITY AND LOCKS>ACCESS KEY>INSPECTION

Is the check result OK?

Yes : Replace the access key. Ref. to SECURITY AND LOCKS>ACCESS KEY>REPLACEMENT

No : Replace the battery. Ref. to SECURITY AND LOCKS>ACCESS KEY>REMOVAL
CHECK DOOR LOCK .
Operate the driver's center door lock switch.

Does the door lock operate?

Yes : Go to 5.

No : Check the door lock control system. Ref. to SECURITY AND LOCKS>DOOR LOCK CONTROL SYSTEM>INSPECTION
CHECK HARNESS .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from the keyless access control module.
3. Using a tester, measure the voltage between the keyless access control module connector and chassis ground.
  Connector & terminal
  
  (i91) No. 1 (+) - Chassis ground (-):
  
  (i91) No. 4 (+) - Chassis ground (-):
Is the voltage 10 V or more when the ignition switch is turned to ON?

Yes : Go to 6.

No : Check the keyless access control module power supply circuit.
CHECK HARNESS (OPEN CIRCUIT) .
Using a tester, measure the resistance between the keyless access control module connector and chassis ground.

Connector & terminal

(i91) No. 20 - Chassis ground:

(i92) No. 17 - Chassis ground:

Is the resistance less than 10 Ω?

Yes : Replace the keyless access control module. Ref. to SECURITY AND LOCKS>KEYLESS ACCESS CONTROL MODULE>REMOVAL

No : Repair or replace the open circuit of harness.