Direct answer
On the covered Kohler standby generator, Advanced Diagnostic means shutdown during the reduced-speed portion of an exercise. The engine then restarts, runs at full speed for two minutes and stops; the controller returns to AUTO and the exercise schedule is unchanged. First, open the event history and confirm it shows Advanced Diagnostic Active.
Definition versus diagnosis
The display names a detected condition—not an automatically failed part.
What this covers
- Kohler standby generator covered by the cited source
- Displayed code or documented alias: Advanced Diagnostic
- The exact operating state described by the manufacturer
What it does not cover
- ×Another product type or original-manufacturer platform
- ×A visually similar but different code
- ×Internal live electrical, sealed-system, gas, battery-cell or control-board repair
Match every character and the exact product
ReversiblePhotograph the complete display and product label. This record covers Advanced Diagnostic on Kohler residential standby generator sets using the RDC2/DC2 controller; the displayed fault text, warning/shutdown behaviour and available customer checks vary by model and controller firmware. Confirm against the operation manual for the exact model.
Preserve the failure state
ReversibleOpen the event history and confirm it shows Advanced Diagnostic Active. Record the operating stage, recent change and what still works before clearing the message.
Correct only the documented fault domain
ReversibleIf the set does not restart and return to AUTO, Kohler directs checking for other faults that prevent operation. Do not borrow a reset or meaning from a similar code, product or model year.
Verify once, then respect the service boundary
ReversibleRepeat only the shortest safe action that reaches the original stage. If Advanced Diagnostic returns, stop repeated resets and use model-specific manufacturer support.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Exact questions
Common follow-ups
What does Advanced Diagnostic mean on a Kohler standby generator?+
Shutdown during the reduced-speed portion of an exercise. The engine then restarts, runs at full speed for two minutes and stops; the controller returns to AUTO and the exercise schedule is unchanged.
Can I reset Advanced Diagnostic without fixing the cause?+
A reset may hide the display temporarily but does not correct the documented fault. Record the code and complete only the safe checks first.
Why is the complete model number required?+
Manufacturers reuse characters across platforms. The model number determines which official table, controls and service boundary apply.
When should I stop?+
Stop for smoke, arcing, burning odor, uncontrolled water, gas odor, battery swelling, extreme heat or any condition the manufacturer directs to professional service.
Answer for the exact device and software version shown above.