Network, generic

U008B Vehicle Communication Bus G (+) Open

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

On Vehicle Communication Bus G, U008B flags an open (+) conductor, which on a CAN means CAN-High. No manufacturer documents U008B publicly. A useful clue comes from the termination: Texas Instruments describes a high-speed CAN line ending in a 120-ohm resistor at each end, which a meter across CAN-High and CAN-Low sees as about 60 ohms. With CAN-High broken, only the resistor on the measuring side remains in the loop and the reading rises to roughly 120 ohms; on the other side of the break it is the same, which helps locate the gap. Meanwhile the far nodes miss part of the signal and fall silent or drop frames, and as NXP notes, transceivers do not report open lines themselves. Check the (+) wire through every connector of Bus G.

Likely causes

(+) wire of Bus G broken at a hinge, seat or door passage
Terminal of the (+) wire pushed out of its connector cavity
Corroded splice in the (+) wire

Symptoms

  • Some modules on Bus G not reachable with a scan tool
  • Intermittent faults that change with temperature or 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 g wiringmodule connector

Related codes

U0089U008CU008EU0094

References: ti.com, nxp.com, law.cornell.edu.