U0259Lost Communication With Special Purpose Vehicle Control Module A
- Generic OBD-II code · Network
- How the car detects it
- A special purpose vehicle control module is extra electronics for converted vehicles such as police cars, ambulances or work trucks. GM sells one from 2024 as Universal Vehicle Module (option KGU) and calls it special purpose vehicle control module for Silverado and Sierra pickups and the Tahoe and Blazer EV police vehicles. It reads switches and serial data, drives configurable outputs, offers a subset of J1939 data to upfitter equipment, and retrofitting it requires BCM and ELM reprogramming (PIT6315, Upfitter bulletin 203-b). Deutz's EMR engine controller for off-highway machines lists U0259-00 as a timeout of its tractor-trailer bridge. When slot A stops sending, the conversion functions it controls drop out, while the base vehicle normally drives on. Slots B to D are U025A to U025C, invalid data U055A.
- What you may notice
- Light bar, siren or other conversion functions inoperative or stuck
- Upfitter switches or configurable inputs without effect
- Likely causes
- LikelyAdd-on controller without power or ground from the body builder's circuits
- PossibleDamaged or wrongly spliced bus wiring from the conversion
- PossibleRetrofit without the required vehicle configuration and module programming
- RareInternal failure of the special purpose controller
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.