U1524 on 2013-2019 Cadillac XTS (Luxury, Premium, Platinum, V-Sport, Vsport) — Lost Communication With Right Headlamp on LIN Bus
1 vehicles · 1 makes · $200-$900 repair
Most Reported On
U1524 is an OBD-II diagnostic trouble code meaning “Lost Communication With Right Headlamp on LIN Bus.” A General Motors-specific network code. The headlamp control module (or headlamp leveling control module) stopped receiving the expected periodic message from the right headlamp over the LIN (Local Interconnect Network) bus — a single-wire, low-speed serial link between a master module and its subsystem devices. In practice the right headlamp, its leveling function, or its adaptive/DRL features may stop responding to commands. The lamp itself may still illuminate on a basic circuit even though the module can no longer talk to it. This code is most commonly reported on 2013-2019 Cadillac XTS (Luxury, Premium, Platinum, V-Sport, Vsport), with repair costs ranging from $200 to $900.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
U1524 does not use the standard P/B/C/U prefix. It may be a manufacturer-specific code, so verify that a scanner supports your exact year, model and module before buying.
FAQ
What does U1524 mean?
U1524 stands for "Lost Communication With Right Headlamp on LIN Bus." A General Motors-specific network code. The headlamp control module (or headlamp leveling control module) stopped receiving the expected periodic message from the right headlamp over the LIN (Local Interconnect Network) bus — a single-wire, low-speed serial link between a master module and its subsystem devices. In practice the right headlamp, its leveling function, or its adaptive/DRL features may stop responding to commands. The lamp itself may still illuminate on a basic circuit even though the module can no longer talk to it.
What are the most common causes of U1524?
The most common causes of U1524 are: Failed LED headlamp assembly or its integrated driver/ballast module (the LIN node itself), Open, shorted, or corroded LIN serial data wire between the headlamp and the control module, Poor connection, water intrusion, or pushed-out pins at the headlamp connector, Loss of ignition power or ground to the right headlamp assembly, Faulty headlamp control module / headlamp leveling control module, Aftermarket headlamp or HID/LED retrofit that does not support LIN communication. The specific cause varies by vehicle.
How much does it cost to fix U1524?
Repair costs for U1524 range from $200 to $900, depending on the vehicle and root cause.
Which vehicles are affected by U1524?
Au7o has documented U1524 across 1 vehicle models from 1 manufacturers: Cadillac.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.