Body, generic

B0226 Headlamp Auto-Leveling Front Sensor

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The publicly available J2012 lists have no B0226, and no maker documents it for headlamp levelling. Saab uses the number in its 9-3 climate control: B0226 01 is a short to B+ in the recirculation motor circuit, possibly causing stale air or misted windows. Automatic levelling, as HELLA explains, keeps the beam cut-off steady as the load changes. A control unit compares front and rear axle sensors with stored values and drives small motors in the headlamps; dynamic systems, found on almost all xenon cars, also correct for braking and acceleration. Compact cars often omit the front sensor. Each axle sensor is an angle sensor whose lever is clipped to a suspension arm; older ones use a potentiometer, newer ones inductive measurement. With the front sensor failed, the beam stays where it was.

Likely causes

Lever or coupling rod of the front axle sensor bent, broken or detached
Connector or wire at the sensor corroded or damaged by road splash
Sensor worn out internally or not calibrated after replacement or suspension work

Symptoms

  • Headlamp levelling warning shown and beam height no longer adjusts
  • Oncoming drivers flash because the beam is set too high under load

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–450
Time0.5–2 h

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

Parts involved

front ride height sensorheadlamp leveling modulebody control module

Related codes

U0181U0482

References: hella.com, hella.com, saabwisonline.com.