U1540 on 2013-2019 Cadillac XTS (Luxury, Premium, Platinum, V-Sport, Vsport) — Body Control Module Lost Communication With Right Rear Window Motor on LIN Bus
1 vehicles · 1 makes · $200-$900 repair
Most Reported On
U1540 is an OBD-II diagnostic trouble code meaning “Body Control Module Lost Communication With Right Rear Window Motor on LIN Bus.” Manufacturer-specific (General Motors — Buick, Cadillac, Chevrolet, GMC). The body control module stopped receiving the supervised periodic messages it expects from the right rear power window motor module over the single-wire LIN serial data bus. The usual symptom is the right rear window not responding to the switch, working intermittently, or losing its express-up/anti-pinch function. It is a comfort-system fault, not a drivability or safety fault. 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
U1540 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 U1540 mean?
U1540 stands for "Body Control Module Lost Communication With Right Rear Window Motor on LIN Bus." Manufacturer-specific (General Motors — Buick, Cadillac, Chevrolet, GMC). The body control module stopped receiving the supervised periodic messages it expects from the right rear power window motor module over the single-wire LIN serial data bus. The usual symptom is the right rear window not responding to the switch, working intermittently, or losing its express-up/anti-pinch function. It is a comfort-system fault, not a drivability or safety fault.
What are the most common causes of U1540?
The most common causes of U1540 are: Failed right rear window motor / regulator module, Open, short, or high resistance in the LIN circuit to the door, Damaged wiring in the door-jamb harness boot from repeated door movement, Corroded or backed-out connector terminals at the motor or door module, Loss of battery power or ground to the window motor module, Faulty body control module. The specific cause varies by vehicle.
How much does it cost to fix U1540?
Repair costs for U1540 range from $200 to $900, depending on the vehicle and root cause.
Which vehicles are affected by U1540?
Au7o has documented U1540 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.