Network, generic

U043B Invalid Data Received From Front Distance Range Sensor - Left

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U043B covers the left front distance sensor, usually a short-range corner radar that widens the view of adaptive cruise and collision assistance beyond the central long-range unit; that one has U0433, the right corner U043C. A receiver sets U043B when the left sensor's object or status frames arrive but fail plausibility or protection checks. No manufacturer documents U043B publicly. GM's 2025 EOCM3 tables list only the lost-contact partner U023D for the left front short-range radar: frames absent longer than 0.2 s end adaptive cruise (special Type C), which indicates how the assistance controller is likely to react to corrupted data as well. Expect assistance features reduced or switched off and a prompt to clean or check the sensor area.

Likely causes

Left corner radar misaligned or damaged after a bumper impact
Corner radar software not matching the assistance controller
Moisture or corrosion in the left sensor connector

Symptoms

  • Adaptive cruise or lane change assistance unavailable
  • Message to clean or check front sensors

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–900
Time0.4–2.5 h

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

Parts involved

front distance sensor left

Related codes

U023DU043CU0433

References: gsi.ext.gm.com, en.wikipedia.org.