Network, generic

U0223 Lost Communication With Door Window Motor B

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modeNo

U0223 points to door window motor B dropping out of communication; GM lists it in PIT5981B together with A, C and D for its 2021–2025 full-size SUVs. Smart motors keep learned data: Atmel's AVR480 reference stores blocking points and anti-pinch parameters in EEPROM and acquires them while the window is first operated. GM TechLink (April 2021, Equinox and Terrain 2018–2021) warns that after unplugging the motor or the door harness the motor must be normalised, otherwise express-up and the small upward index when the door shuts are lost. A lost learn is a different fault from U0223, though: a motor without its learned values still answers on the bus. Both often show up after work inside the door. No MIL.

Likely causes

Motor or door connector not fully reconnected after door trim work

Broken wire in the door harness

Electronics of window motor B failed

Blown fuse or missing ground for the motor

Symptoms

Window in the affected door does not move at all
Express-up unavailable
Fault appears right after door panel or glass work

Repair estimate

DifficultyMediumDIY possible

Parts and labour€0–600

Time0.3–2.5 h

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

Parts involved

door window motor blin bus

References: static.nhtsa.gov, ww1.microchip.com, gm-techlink.com.