Code result
U0003
High Speed CAN Communication Bus Open
High severity
What it means
The CAN-High line of the high-speed bus is open. Without the differential pair, the controller cannot decode any traffic and reports loss of all participating modules at once. Often follows a wiring repair, accident damage, or a corroded connector pin.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
CAN-High wire broken or pin pushed back
highOne of the most commonly reported causes for this code — check this first.
Corroded module connector
mediumA plausible cause — test and verify before replacing parts.
Harness damage after repair or accident
mediumA plausible cause — test and verify before replacing parts.
Related help
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