DTC U1651: Lost Communication With Meter (UART)

DTC detecting condition:

UART data from combination meter is not received.

Trouble symptom:

LCD is not displayed.

Wiring diagram:

Multi-function display (MFD) system Ref. to WIRING DIAGRAM , Multi-function Display (MFD) System.

Fig 1: Combination Meter To MFD- Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK LAN SYSTEM . Read the DTC of the LAN system using the Subaru Select Monitor. Ref. to OPERATION , Read Diagnostic Trouble Code (DTC).	Are any DTCs displayed?	Perform the diagnosis according to DTC.	Go to step 2 .
2 CHECK CONNECTOR . Disconnect the MFD connector and combination meter connector. Connect the disconnected connectors. Read the DTC of the MFD using the Subaru Select Monitor. Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .	Is DTC U1651 a current malfunction?	Go to step 3 .	There was poor contact of connector.
3 CHECK HARNESS (OPEN CIRCUIT) . Disconnect the MFD connector and combination meter connector. Using the tester, measure the resistance between terminals. Connector & terminal (i10) No. 28 - (i122) No. 9:	Is the resistance 10 Ω or less?	Go to step 4 .	Repair the open circuit of harness or replace harness.
4 CHECK HARNESS (GROUND SHORT CIRCUIT) . Using the tester, measure the resistance between terminals. Connector & terminal (i122) No. 9 - Chassis ground:	Is the resistance 10 Ω or less?	Repair the short circuit of harness or replace harness.	Go to step 5 .
5 CHECK COMBINATION METER . Replace the combination meter. Ref. to Combination Meter . Read the DTC of the MFD using the Subaru Select Monitor. Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .	Is DTC U1651 a current malfunction?	Go to step 6 .	There was something wrong with the combination meter.
6 CHECK COMBINATION METER . Replace the current combination meter with the original combination meter. Replace the MFD. Ref. to Multi-function Display (MFD) . Read the DTC of the MFD using the Subaru Select Monitor. Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .	Is DTC U1651 a current malfunction?	Replace the combination meter. Ref. to Combination Meter .	There was an abnormality in MFD.