Network, generic

U0095 Vehicle Communication Bus H (+) Low

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modePossible

U0095 indicates that the (+) wire of Vehicle Communication Bus H is held too low, usually through a ground short (CAN-High on a CAN). No public manufacturer document uses U0095. The effect depends heavily on the bus type. On a high-speed CAN, onsemi found that no frame can be sent with CAN-High grounded; the stuck node kept retrying in short bursts, its transmit line active only about 2 % of the time, and the supply current fell to about 50 mA. Repeated failures end in bus off, which would add U007A. NXP's fault-tolerant TJA1055, by contrast, copes with a grounded CANH without even leaving differential reception. The same code can therefore mean a dead network on one car and an unnoticed defect on another.

Likely causes

(+) wire chafed against the body

Harness pinched during a repair or installation

Faulty transceiver holding the (+) line low

Symptoms

On high-speed CAN: all Bus H modules fail together
On fault-tolerant CAN: little or no noticeable effect

Repair estimate

DifficultyHardWorkshop job

Parts and labour€60–800

Time1–5 h

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

Parts involved

bus h wiringcan high wire

Related codes

U007A U008C U0094 U0096 U0098

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