Network, generic

U0094 Vehicle Communication Bus H (+) Open

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0094 reports that the (+) wire of Bus H is interrupted, CAN-High where Bus H is a CAN. No manufacturer documents U0094 publicly. How much the break matters depends on the kind of CAN. A fault-tolerant low-speed CAN up to 125 kBd, built with transceivers such as NXP's TJA1055, keeps receiving differentially with a broken CANH wire, and the chip's error output toggles only if the gap separates the sending node from the listening one, so the module may see the fault only now and then. A high-speed CAN loses the far nodes. For locating it, Nissan's chart separates a break in the main line from one in a branch to a single module, judged by the resistance and voltages measured at the diagnostic socket.

Likely causes

Broken (+) wire, e.g. at a hinge or flexing harness section
Terminal pushed out of a connector
Corroded splice with high resistance

Symptoms

  • Single modules on Bus H not reachable
  • Fault appears intermittently or with 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 h wiringcan high wire

Related codes

U008BU0092U0095U0097

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