Code result
U0070
Communication Bus \"B\" Performance
Moderate severity
What it means
The secondary communication bus (Bus B, often a chassis or comfort sub-bus) shows reduced performance — high error rate, intermittent dropouts, or framing errors. Bus is still alive but unreliable.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Marginal wiring or corroded connector
highOne of the most commonly reported causes for this code — check this first.
EMI interference (aftermarket equipment)
mediumA plausible cause — test and verify before replacing parts.
Gateway module routing CAN messages incorrectly
lowLess common, but worth ruling out after the more likely causes.
Related help
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