Network, generic

U0125 Lost Communication With Multi-axis Acceleration Sensor Module A

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0125 concerns the inertial measurement unit that bundles yaw rate plus lateral and longitudinal acceleration on one bus node. GM uses the code widely: the 2019 XT4 brake controller (EBCM) flags a missing IMU frame after 0.1 s, the 2025 object-detection module after 0.05 s and then disables adaptive cruise; both are Type C without MIL. Saab's 9-5 list adds symptom bytes 71, 72 and 74 for invalid data, wrong message counter and checksum. Field cases: a broken wire at connector X411 under the left rear (Equinox/Terrain, PIT5171B) and an EBCM reflash for 2020 Equinox (N192285670). Stellantis calls the part Dynamics Sensor. U0123/U0124 name single-axis modules instead.

Likely causes

Wire broken inside the insulation or rubbed through near a chassis connector (GM X411)
Loose or corroded plug at the inertial sensor
Brake controller software that drops the sensor (reflash released)
Multi-axis sensor internally faulty

Symptoms

  • Service ESC / StabiliTrak message, traction and ABS lamps
  • Adaptive cruise control or all-wheel drive unavailable
  • Electric parking brake warning on some models

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–900
Time0.5–3 h

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

Parts involved

inertial sensor clustercan bus wiring

Related codes

U0123U0124U0122U0074U0126

References: gsi.ext.gm.com, gsi.ext.gm.com, saabwisonline.com, static.nhtsa.gov.