Ok. I've seen countless posts across multiple forums about 2018/2019 GTIs limited to 40 MPH, but have never read a consistent root cause and solution. I'm going to build on my earlier post to lay out what I've done based on professional support, not yet from a dealer tech.
I'm hoping someone has concrete knowledge of the issue, root cause, and most likely solution. I do have the CandooPro tool to provide me with system diagnostic insights. To recap my vehicle and issue:
- 2018 GTI SE 155, 14 hours on clock at purchase, which was late April 2023.
- Runs great; tons of power up to a speed limit of 41.7 - 41.9 MPH as verified by independent GPS, and duplicated by the cluster GPS speedo. RPM is a steady 6040 when in the water at that speed.
- Plugs pulled and changed, but were perfect. Compression tested, and were 168 PSI on the button for each cylinder with my gauge. Impeller has extremely minor imperfections, but nothing that could cause a 13 MPH reduction is the typical 55 MPH top end reported for smooth water.
- Removed the cluster, sent into a professional to reflash to the correct Non-Rental file (99HP limit) calibration using BUDS2. No change.
- Hired a service to remotely diagnose the systems via BUDS2. Cluster had yellow status and could not be accessed to read configuration. Some modules were flagged for 130 model. vice 155. All modules were set to 155 model.
- Service reflashed/overwrote the ignition/fuel mapping to a light performance tune. Between changes made in BUDS and performance tune, no change in speed.
- When the ski it jumps out of the water in ocean conditions, the engine revs up to the new 8000+ limit. Once it lands it's again limited to the water speed for conditions, not exceeding 42 MPH. My speed tests were all conducted in a large harbor, outside of the no-wake zone, with smooth conditions.
- I was told by one of the professionals that BRP has a known issue whereby on some 2018/2019 GTIs they cannot convert the system out of Rental mode. They're working on a fix.
- I was told by another Seadoo master mechanic (not at the dealer) that the 99HP calibration feature must be revised in both the cluster and the ECU. Of course, if it can't be accessed when in the system with BUDS2, one cannot confirm that it has been updated. In fact, I question the yellow icon status.
I one hundred percent believe that the consistency of the speed limitation eliminates any mechanical issue as a root cause. Plus none of my other findings support anything less than a perfect condition power train.
Does anyone know exactly how the Rental mode calibration files limit craft speed? It could be throttle response limit or GPS. I don't believe anything changes the mapping. For instance ECO and Touring modes are throttle response changes implemented in conjunction with a single mapping profile, based on information provided by one of the professionals.
Barring any new information, or going to a dealer, which I may do at this point, my inclination is to purchase a new BRP, not Chinese, cluster, have it flashed and married to my ECU (which I can also do with CandooPro).
What do you all think?
