Network, generic

U0096 Vehicle Communication Bus H (+) High

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modeNo

U0096 is set once excessive voltage appears on the Bus H (+) wire, as from a short to battery or to the module supply; on a CAN this is CAN-High. U0096 is not documented by any manufacturer in public. On a high-speed CAN such a short often leaves traffic running; NXP lists CAN-High to battery and to the 5 V supply among hidden failures. A fault-tolerant low-speed CAN reacts in steps. NXP's TJA1055 first switches to single-wire reception over CANH after a time-out and, if the line stays high, moves on to CANL and shuts off its CANH driver; the delays keep radio interference from triggering it. When the short is gone, the chip returns to normal by itself. Look for chafing against a supply wire or water in a connector.

Likely causes

(+) wire touching a supply wire

Water in a connector bridging the (+) pin to a supply pin

Faulty transceiver driving the (+) line high

Symptoms

Often no symptom, code found during a scan
Sporadic dropouts on Bus H

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

U008D U0095 U0099

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