DTC U1650 Invalid Data Received From Meter (UART)

DTC DETECTING CONDITION:

There is an abnormality in UART data from combination meter.

TROUBLE SYMPTOM:

LCD is not displayed.

WIRING DIAGRAM:

Clearance Light and Illumination Light System <Ref. to Clearance Light and Illumination Light System .>

Fig 1: Clearance Light And Illumination Light System Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK LAN SYSTEM. Read the DTC of body integrated unit and LAN system using Subaru Select Monitor. <Ref. to OPERATION , Read Diagnostic Trouble Code (DTC).> <Ref. to OPERATION , Read Diagnostic Trouble Code (DTC).>	Is any DTC other than DTC U1650 displayed?	Perform the diagnosis of DTCs other than U1650.	Go to step 2.
2 CHECK FUSE. Check the fuse No. 31 in the fuse & relay box.	Is the check result OK?	Go to step 3.	Replace the fuse. When the fuse is blown easily, check the wiring.
3 CHECK HARNESS. Disconnect the body integrated unit connector. Turn the ignition switch OFF → ACC. Measure the voltage between body integrated unit connector and chassis ground using tester. Connector & terminal (B280) No. 32 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 4.	Repair the ACC power supply circuit of the body integrated unit.
4 CHECK CURRENT DATA OF INTEGRATED UNIT. Connect the Subaru Select Monitor. Turn the ignition switch to ON. Check the current data «ACC voltage» of the body integrated unit. <Ref. to Read Current Data .>	Is the voltage 10 V or more?	Go to step 5.	Inspect and correct the body integrated unit connector. If there is no abnormality, replace the body integrated unit. <Ref. to Body Integrated Unit .> (There may be a poor contact in the body integrated unit connector ((B280) terminal No. 32), or an internal malfunction of the integrated unit.) (If the current data indicates ACC voltage value ≈ Battery voltage, there will be no malfunction up to inside of the integrated unit. If U1650 is still detected in this condition as current malfunction, perform step 5 and subsequent procedures.)
5 CHECK CONNECTOR. Disconnect the MFD connector and the 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 U1650 displayed? (Current malfunction)	Go to step 6.	There was poor contact of connector. Repair the poor contact of connector. (Poor contact in combination connector (i10) terminal No. 20 or MFD connector (i122) terminal No. 9)
6 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 U1650 displayed? (Current malfunction)	Replace the MFD. <Ref. to Multi-function Display (MFD) .>	There was something wrong with the combination meter.