Network, generic

U0260 Lost Communication With Seat Control Switch Module A

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Many power seat switches now contain electronics that scan the keys and report the result over a LIN or multiplex link rather than carrying motor current. A Lear patent describes a seat motor assembly with integrated electronics that talks to an external switch over a one- or two-wire multiplex link. Mercedes shows such a switch failing for series 206 to 297, for example C-, E- and S-Class, GLC and EQS: the door-mounted switch group for seat adjustment (front left: SSE-VL) could remain in sleep mode after a software error, so the seat did not move although the quick test stored no fault; unplugging the switch resets it, new switch software prevents a repeat (LI82.00-P-080029). No manufacturer documents U0260 publicly. When switch module A stops sending, its seat cannot be adjusted from it; switch B is U0261.

Likely causes

Switch module software stuck in sleep mode, reset by unplugging and fixed by update
Loose or corroded connector or broken wire at the switch in the door or seat trim
LIN line to the seat module shorted or open
Internal failure of the switch module

Symptoms

  • Seat cannot be adjusted with its switch
  • Memory, lumbar or massage keys on that switch without function

Repair estimate

DifficultyEasyDIY possible
Parts and labour€0–400
Time0.2–1.5 h

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

Parts involved

seat control switch module avehicle bus wiring

Related codes

U0561U0261U0271U0272

References: static.nhtsa.gov, patents.google.com.