Faulty front headlamp leveling sensor (height sensor) due to internal wear or water intrusion; Damaged or corroded electrical connector at the sensor; Broken, chafed, or shorted wiring in the sensor circuit; Failed sensor linkage or bracket, causing incorrect sensor reading; Water or road debris contamination affecting the sensor mechanism; Faulty headlamp leveling control module (less common)

DTC codes / B02xx · Airbags, seats, doors, lights and comfort systems / B0226

B0226Headlamp Auto-Leveling Front Sensor

Q: What does code B0226 mean?

Headlamp Auto-Leveling Front Sensor. B0226 indicates that the body control module (BCM) or headlamp leveling control module has detected a fault with the front height sensor used for automatic headlamp leveling. The sensor reports an out-of-range voltage or implausible signal, preventing the system from correctly adjusting the headlamp aim based on vehicle load.

B0226 indicates that the body control module (BCM) or headlamp leveling control module has detected a fault with the front height sensor used for automatic headlamp leveling. The sensor reports an out-of-range voltage or implausible signal, preventing the system from correctly adjusting the headlamp aim based on vehicle load.

SystemBody

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

Headlamp auto-leveling warning light illuminated on the dashboard
Headlamps may point too high or too low, causing poor visibility or glare to oncoming traffic
Headlamp aim may not adjust when the vehicle is loaded or unloaded
Often no symptoms besides the warning light, with headlamps appearing to function normally
Intermittent warning light that appears over bumps or in wet weather due to a loose connection

Common causes, most likely first

Faulty front headlamp leveling sensor (height sensor) due to internal wear or water intrusion
Damaged or corroded electrical connector at the sensor
Broken, chafed, or shorted wiring in the sensor circuit
Failed sensor linkage or bracket, causing incorrect sensor reading
Water or road debris contamination affecting the sensor mechanism
Faulty headlamp leveling control module (less common)

How to diagnose and fix it

Inspect the front height sensor and its linkage for physical damage, corrosion, or debris; clean or replace as needed
Check the sensor electrical connector for tightness, corrosion, and water intrusion; clean and reseat
Measure reference voltage and ground at the sensor connector to verify power and ground circuits
Test the sensor signal voltage while manually moving the suspension or sensor arm to check for smooth variation
Compare sensor signal with a known-good sensor or use a scan tool to view live data and confirm erratic or out-of-range readings
Replace the front height sensor if tests confirm it is faulty, then clear codes and perform headlamp aiming calibration if required
If the sensor and wiring are good, diagnose the headlamp leveling control module and its communication circuits

Height Sensor Diagnostics and Calibration Traps

A common oversight is replacing the sensor without checking the linkage; a bent bracket or worn ball joint can cause the sensor to read incorrectly even when new.
The sensor may test fine with a multimeter but still set the code intermittently due to a worn internal track that only fails at certain suspension positions.
After replacing the sensor, many vehicles require a headlamp leveling calibration using a scan tool; skipping this step can leave the headlamps misaimed and the code may return.
Water intrusion into the sensor connector is a frequent cause, especially in regions with road salt; dielectric grease can help prevent recurrence.
This code can be set by a weak battery or charging system issue causing low voltage to the leveling module, so check battery health before condemning the sensor.

Can I keep driving with B0226?

The vehicle remains safe to drive because the headlamps still function, but the automatic leveling feature is disabled. Avoid driving at night with heavy loads until repaired, as misaimed headlamps can reduce visibility or dazzle other drivers.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.