OBD-II code · Network
U018A Lost Communication With Headlamp Leveling Control Module B
ECU lost communication with headlamp leveling control module B (auto-levelling for HID/LED headlamps).
Is it safe to drive with U018A?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyModule unpowered
- Less likelyGateway module routing CAN messages incorrectly
- Less likelyCAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Headlamp Leveling Module B, Can Bus
Related codes
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- U0188Lost Communication with Audio Rear Control Module
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- U0191Lost Communication with Television Tuner Module
- U0192Lost Communication with Personal Computer
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.