U0274Lost Communication With Lighting Driver Control Module B
- Generic OBD-II code · Network
- How the car detects it
- U0274 is stored when the second lighting driver control module stops answering on its network. Lincoln documents a B unit on the 2025 Navigator, listed as LDCMB and updated with the same release 25.10.08 as its three siblings, but gives no position for it. What a silent driver does on its own is shown by TI's TPS92520-Q1 LED driver: a communication watchdog, set to about 1.67 s by default, switches the chip to limp-home current from preset registers when commands stop arriving. The lamp therefore often stays lit at a fixed level although the controller has lost the module. No manufacturer documents U0274 publicly. U0575 covers implausible data from the same unit.
- What you may notice
- Lamp stays at one fixed brightness and ignores dimming
- Lighting fault message
- Adaptive light functions switched off
- Likely causes
- LikelyBus wire or connector to driver module B open or corroded
- PossibleSupply or ground of driver module B missing
- PossibleDriver module B software not current after an update
- RareDriver module B internally faulty
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.