Obdaryn

U0088Vehicle Communication Bus F (-) Shorted to Bus F (+)

  • Generic OBD-II code · Network
  • Can trigger limp mode
How the car detects it
With U0088 the two conductors of Vehicle Communication Bus F are bridged to each other. Signalling on both FlexRay and CAN rests on the difference between the wires, so with them joined there is none: a FlexRay receiver such as NXP's TJA1081B sees a difference below its activity threshold and treats the line as idle, while every sending node reads back something other than what it transmits and sets its bus error flag. On a single channel this ends all exchange on Bus F, which is why modules elsewhere then log the silent partners as lost. Volvo names a short between CAN-High and CAN-Low as one cause of U008088 on its truck datalink 7. For CAN, onsemi's bench tests likewise show a bridged pair stopping all traffic. Isolate sections by unplugging connectors while measuring between the wires.
What you may notice
  • Complete loss of the functions served by Bus F
  • Lost-communication codes for several modules
Likely causes
  • LikelyBus F pair crushed so both wires touch
  • PossibleWater or corrosion bridging both wires in a splice or connector
  • RareTransceiver with an internal short between its bus pins
Repair
Hard · Usually a job for a workshop.Typical cost: €80 – €1,000

Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.