Thread: Diagnostic Tools (2025)

Hi All,

Apologies for asking this question again - but searches only find old info and i want to make sure i have the right answer.

I'm upgrading (or downgrading some may say) from a D4 to a 2019 SD6 D5. I always wish I bought a GapIID when I first bought the D4 - it would have paid for itself.
I want to buy a good diagnostic tool for D5.
Some searches suggest the GapIID is not as functional on the D5 as it was on the D3/D4 - not sure if this is old news or still the case.

Questions:
1) Whats the best tool for D5 - i assume it's still the GapIID G4?
2) If the functionality is limited, am i better off going a cheaper tool instead (eg iCarSoft)?
Wishlist:

• Review and reset ALL codes.
• BMS reset, service interval reset, etc.
• Disable stop-start
• TTS on suspension and other adjustments.
• Ideally the ability in future to map out EGR, Adblue and DPF if they give me trouble later on (if this is even possible).

Thanks all.

I believe the D5 Australia Facebook group would be a good source of information as would the GAP website: https://www.gap-diagnostic.com/products/iidtool/

Seems to indicate a significant amount of functionality for your intended vehicle.