Code result
U0259
Lost Communication With Special Purpose Vehicle Control Module A
Moderate severity
What it means
The vehicle bus reports loss of communication with special-purpose vehicle (SPV) control module A. Upfit functions like emergency lighting, sirens, fleet relays or PTO/auxiliary systems controlled by this node stop responding.
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
Bus wiring open or shorted
highOne of the most commonly reported causes for this code — check this first.
Module without power or ground
mediumA plausible cause — test and verify before replacing parts.
Module failed
mediumA plausible cause — test and verify before replacing parts.
Related help
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