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U0209 Lost Communication With Seat Control Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0209 means seat control module B is no longer heard. On GM cars of 2010–2015 with heated front seats (LaCrosse, Regal, Verano, Camaro, Cruze, Equinox, Malibu, Sonic, Volt, Terrain) the HVAC module logs it when both seat heaters quit: preliminary information PIC5954 blames intermittent software in seat heating module K29, which is reset by pulling its fuse for five minutes, and PIC5954B adds a reprogramming; replacing the module is ruled out. The 2011 Saab 9-5 list also calls it the front seat heating module. Newer GM SUVs fill the slot differently: PIT5762F (2020–2023 Tahoe, Escalade, Corvette and others) names the driver seat bolster memory module and treats a history entry as ignorable. No MIL.

Likely causes

Seat heating module software hangs (GM K29, reset and reprogram)
Stored history entry from a software anomaly (GM 2020–2023 SUVs)
Fuse or supply of the seat module
Seat harness damaged under the seat

Symptoms

  • Both front seat heaters inoperative
  • Side bolster adjustment of the driver seat does not react

Repair estimate

DifficultyEasyDIY possible
Parts and labour€0–300
Time0.2–1.5 h

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

Parts involved

seat module bheated seat modulecan bus

Related codes

U0208U0210U050AU0164

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.