U0181

Lost Communication With Headlamp Leveling Control Module A

Q: Is it safe to drive with U0181?

Yes for normal driving. The main concern is at night — without auto-leveling the beams may sit too high and dazzle oncoming drivers or too low and under-light the road. Have it corrected.

Q: Can I just clear U0181?

It returns while the module stays offline. The wiring, power, or module fault needs to be repaired to restore leveling.

Communication network (lighting) Generic OBD-II Low

What it means

U0181 means the network has lost communication with the headlamp leveling control module, which automatically adjusts headlight aim for load and road angle. The headlights still work, but without leveling the beams may sit too high or too low. That mainly matters at night, where poor aim can dazzle oncoming traffic or under-light the road, so it's a low-severity but worth-fixing fault.

Low

Can I keep driving? Yes — the headlights still work but may not auto-level. Aim can be off at night, so have it checked, but it's safe for normal driving.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Headlight or lighting warning message on the dash
Headlamps not auto-leveling; beam aim high, low, or fixed
Possible glare to oncoming traffic or poorly lit road ahead at night
Headlamp leveling module unreachable when scanned

Common causes

Most likely first

Open, shorted, or chafed wiring to the headlamp leveling moduleLikely
Corroded or loose connector at the moduleCommon
Blown fuse or lost power/ground to the moduleCommon
Failed headlamp leveling control module or a faulty leveling sensor on its networkLess often
Bus fault preventing the module from reportingLess often

How to diagnose & fix

Work through it in order

Scan all modules and confirm the leveling module is offline.
Check its power, ground, and fuse feeds.
Inspect the wiring and connector at the module for damage or corrosion.
Test the CAN bus lines to the module for open or short.
If wiring and power are good, replace the module, clear the code, and confirm the headlights level correctly.

FAQ

Quick answers

Is it safe to drive with U0181?+

Yes for normal driving. The main concern is at night — without auto-leveling the beams may sit too high and dazzle oncoming drivers or too low and under-light the road. Have it corrected.

Can I just clear U0181?+

It returns while the module stays offline. The wiring, power, or module fault needs to be repaired to restore leveling.

Read & clear U0181 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX