Network, generic

U0289 Lost Communication With DC/AC Converter Control Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0289 belongs to a second DC/AC converter, unit B, in vehicles that generate mains-voltage alternating current at two points, for example a small inverter for a console socket and a stronger one for the bed, or one converter per group of outlets. No manufacturer documents U0289 or describes a converter B in public material. Unit A shows how such a check behaves: GM's body control module on the 2026 Colorado and Canyon flags lost contact as U0288, falsely even on trucks without the outlet. GM's 2023 Silverado and Sierra programme, which later activated the inverter for dashboard and bed outlets by adding a power control module and reprogramming the BCM, shows that option coding decides which converters the network expects. Only the sockets fed by B should fail.

Likely causes

Network configured for a second converter that is missing or not activated
No supply or ground at converter B (fuse, connector)
Bus wiring or connector to converter B damaged
Converter B internally failed

Symptoms

  • Some outlets dead while others still work
  • Power outlet warning message

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–1,500
Time0.3–3 h

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

Parts involved

dc ac converter module bvehicle bus wiring

Related codes

U0288U058AU0589

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