Network, generic

U0082 Vehicle Communication Bus F (+) Open

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

U0082 reports an interrupted (+) wire on Vehicle Communication Bus F. Where Bus F is FlexRay, as Audi's A6/A7 bulletin suggests, this is bus plus (BP); in a CAN it would be CAN-High. FlexRay signals by the voltage difference between BP and BM, and NXP's TJA1081B only accepts activity once that difference exceeds a threshold of about 150 to 300 mV. Nodes beyond a broken BP therefore receive a reduced or missing signal, while the sender keeps seeing its own output intact on its side of the break, so its bus error flag stays quiet. The fault shows as partners that stop answering. No manufacturer documents U0082 publicly; Volvo and Mack trucks fold line breaks on their datalink 7 CAN into U008088. Check BP continuity connector by connector.

Likely causes

(+) wire of Bus F broken at a flex point or after chafing
Terminal of the (+) wire pushed back in a connector
Inline connector of Bus F not fully latched

Symptoms

  • Modules on the far side of the break no longer respond
  • Warnings that come and go with vehicle movement

Repair estimate

DifficultyHardWorkshop job
Parts and labour€60–700
Time0.5–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

bus f wiringmodule connector

Related codes

U0066U0080U0083U0085

References: nxp.com, en.wikipedia.org, static.nhtsa.gov, law.cornell.edu.