Marine diesels (Volvo Penta, Cummins marine, CAT marine, Mercury) are variants of on-highway engines, which means the diagnostic tooling overlaps heavily with truck equipment — plus marine-specific connectors and a few dedicated platforms.
Coverage and tool options
| Segment | Systems covered | Recommended tools |
|---|---|---|
| Volvo Penta | Full diagnostics | PTT (marine mode) / Vodia + cables |
| CAT marine | Full diagnostics + programming | Cat ET + CA3 (same as on-highway!) |
| Cummins marine | Diagnostics + calibrations | INSITE + INLINE 8 |
| Mercury/MerCruiser diesel | Diagnostics | Jaltest marine coverage / OEM |
Getting set up
If you already own truck diagnostic tools, marine work is closer than you think: Cat ET covers CAT marine with the same license; INSITE covers Cummins marine; PTT covers Volvo Penta. The cable catalog includes marine-specific connectors — often the only missing piece.
Tools for this job
Marine cable set
Marine-specific connectors for Volvo Penta, CAT and Cummins marine.
View details →Frequently Asked Questions
Does Cat ET really cover marine engines?
Yes — Cat marine engines are in the same ET license as trucks and equipment. This makes Cat tooling uniquely valuable for operations spanning land and water.
Is marine diagnostics a viable service niche?
Underserved in most markets — marinas sublet diagnostics to truck shops with the right tools. If you're coastal and already own OEM truck software, marine is a low-investment expansion.