Network, generic

U0255 Lost Communication With Front Display Interface Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The front display interface module is the central screen in the dashboard. Ford calls it FDIM; in the U-code table of the 2011 Saab 9-5, a GM design, the same node is the info display module with U0255. GM also shows the code inside a wider network failure: on 2017 Silverado, Sierra, Tahoe, Suburban, Yukon and Escalade, the serial data gateway (SDGM) could lock up while still powered, or its X1/X2 terminals lost tension, and U0255 then appeared among many U codes together with dead gauges, a blank radio display or even no crank. The first step was pulling the gateway fuse for one minute, with gateway software to follow (PIT5586G). So when U0255 shows up with a dozen siblings, the gateway or a shared branch is the suspect, not the screen. A dead display alone points to its own supply. Combined units use U0257.

Likely causes

Gateway module locked up or its connector terminals loose, many U codes at once (GM SDGM)
Display without power or ground (fuse, connector behind the screen)
Damaged bus wiring to the display after dashboard work
Internal failure of the display module

Symptoms

  • Central screen black or frozen
  • Audio, climate or vehicle settings cannot be shown or changed
  • With gateway faults also dead gauges, warning messages or no crank

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–1,100
Time0.3–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

front display interface modulevehicle bus wiring

Related codes

U0556U0257U0256U0146

References: static.nhtsa.gov, saabwisonline.com, static.nhtsa.gov.