How can I confirm a change in my ECU data tables? where do I go for to have my ECU data tables reversed back to when they used to make snaps/pops? As a reminder, I have not had my ECU updated at any point.

Do you see a scenario where my ECU data tables could have been changed due to detailing the car? I came across a post from the AMG forums where snaps/bangs disappeared after an engine bay detail. With the AMG though, there was a check engine light after the detail. In my case, I did not have the engine bay detailed nor I had a check engine light. However, I recall reading about an issue with water ingress in the engine bay from the hood vents that makes wonder about this as an explanation for whey my car lost snaps/bangs after a detail.

 

I thought the hood vent problem only affected the older RWD F-Types…I believe, perhaps someone else could confirm. Pretty sure that is the case. I believe your car has the vents closer to the front of the car, making the issues a non-issue.

 

I agree that it's sad dealers are not as helpful as you'd expect them to be.
This is a bit off topic but I've owned my 2022 for three years now and every time I go in for service or warranty work I ask the dealer's representatives if they can explain how to adjust the volume on the NGPTSQ, which is adjustable according to Jaguar literature. I have yet to even encounter a dealer employee who has ever heard of NGPTSQ, nor has anyone at the dealer offered to attempt to find an answer.

 

Ugh… this is a feature I wish manufacturers would never have incorporated. I’m thankful I don’t notice this in the FType, but my wife’s previous 370z had this and the sound was ridiculously artificial; actually removing from what was a decent sounding V6.

 

Yeah, same, sounds like a feature I’d like to know as little about as possible ;-0

In fact, I think I’ll go back to my regularly scheduled programming of not even knowing this was a thing before now. I certainly haven’t noticed anything, but more often than not I’m driving with my windows open.

 

Had a lengthy discussion with the dealer technician. Basically he thinks there is nothing wrong with the car and he can't come up with an explanation for loosing snaps/pops on deceleration. Also said dealer does NOT have the tools/tech to access ECU/engine mapping...

@Dionysus @DMeister @Wraptor Baby and others who chimed:

1. Could a stock engine tune change on "its own"!? Other than detailing the car, I can't think of anything I did that could have changed for my car. Dealer says NO software upgrade was applied to my car.
2. How can I verify if my stock engine tune changed at any point? And if so, how can I reverse the tune to the state I had in early June before this issue?

 

Hi @alaahnx

Short answer - no - a tune cannot change on its own. Certain conditions can exist where the ECU chooses different fueling and timing tables based on user selections, and sometimes, rarely environment (such as ambient air temps, altitude, pressure, etc.), but temp conditions as these wouldn't cause a permanent change in data tables.

And to your discussion with the dealer tech, NO field personnel on any model car has access to the data tables in an engine management system. At least not with factory tools. As I said in my other post, these data tables are considered intellectual property of the parent company and other than a factory engineer, only hack software can do it. And yes, the hack SW I use I know some dealer techs hold themselves out as "tuners" as well, but they're not doing this under the auspices of the factory.

Back to your situation, when the tech says there have been no SW update to your car, I assume he is looking at the data record for your VIN? This was a big deal in the MB world as MB decided, without notice, of adjusting the tune via SW update when owners brought cars in for simple things like oil changes. MB as a company was "complying" with EPA demands to turn the noise down. Owners left the dealership thinking they were in for an oil change and the dealer wasn't going out of their way bragging about a free SW upgrade. Euro companies in particular, all seemed to take a turn in exhaust sounds around 2019/2020 so thinking the US EPA was/is pressuring them to tone it down.

Now back to the sound changing, the only other way the sounds can change on their own w/o any SW interventions is if some change occurred in the exhaust system, such as a CAT disintegrating causing a change in the exhaust passage way, electronic exhaust valve(s) frozen shut, changes in the fuel type. Just some thoughts.

BTW - I believe one of the SW upgrades MB used when owners brought cars in for simple stuff was labeled a NAV system update. The company wasn't bragging about changing exhaust sounds they just did it and, to my knowledge, the dealers weren't aware any other SW changes were made, just a NAV update so they couldn't explain it.

I'm not trying to suggest a conspiracy here, just sharing some campfire stories. I just don't have the same hard connections with Jaguar as I do with other brands.

 

Sorry, I should have expanded on this above, but it was getting long anyway.

On fuel - Are you experimenting with fuel or fuel additives of any kind? Octane boosts? Ethanol? Might be a longshot, but if fuel stoichiometry has changed and depending how the EMS is programmed (or lack of it) to handle changes I could see a possibility for a change in deceleration.

 

I had the same issue with my 2019. But mine was after a PCU update from the dealer. Oddly enough My tune says it is still on the ECU but something is not the same.

 

did you try anything to solve? Or living with it, as a safe option?

 

Tried a different station with Octane additive once: did not notice a change, but that was the extent of me chasing fuel as the suspect.

 

Man such rich knowledge and experience; thank you sir for sharing it @Dionysus

Since I have not visited the dealer prior to the sound change, and ECU mapping won’t change on its own permanently, I think I should chase the exhaust/CAT for next step troubleshooting. My dealer claims valves are working and my exhaust/CAT is patent or “I would have power loss and/or lights in the dash”. Now I am thinking, based on your feedback, issue is most likely a CAT problem that is big enough to mute my deceleration snaps/bangs but also small enough to not manifest as power loss or lights in the dash. Do you agree?

 

Outside of trying to load my ECU tune back onto the car and getting the message that the same file was on the car already I did not.

 

This and another recent thread titled Evap Recall is the kind of SW upgrade where the factory could make changes to the DFCO under the guise of this recall and not needing to explain it. Every car that comes in for service gets it free, and/or gets a letter notifying a free recall is available for their car.

https://www.jaguarforums.com/forum/f...-purge-281378/

For those where the exhaust sound is suddenly different than it was at one time, it would be interesting if anyone can recall a nexus to having this flash done. This is similar to what MB was doing - flashing the ECM under the title of something that was innocuous...and free.

Not trying to create a conspiracy here, but this could explain why, for no reason, it just doesn't sound like it did.

 

Sounds completely feasible to me. I hate shady dealership practices though. I specifically asked if they were going ot mess with the ECU and was told no.

 

Unfortunately they can tend to tell people one thing and do another. I don’t trust many dealerships based on my experiences over the years.

 

Keep in mind, the dealer network has no access (or detail knowledge) as to the content of a SW flash or SW rev roll. They only know what the factory describes the flash is for. The factory can say - a mandatory flash of all the following cars upgrades the NAV (for instance), but also includes some data mods to another function that is conveniently missed in the field description.

After a certain year with most performance cars that use exhaust flaps, the technology moved from a simple vacuum system to a much more complex electric (step motor) system. With Jaguar I believe that was MY 2021. So any MY 21 and newer will have this newer system. With it, the ECU controls much more and in a much wider range how the flaps work and when.

I'll give a couple of examples of what the data tables look like. Again, this came using hack SW. A dealer/dealer tech wouldn't have a clue about these details (unless the tech is also a tuner on the side)

This is an example of the hierarchy data tables controlling the movement of the exhaust flaps, In the lower right, this is the SECOND level access. Each of the greyish bubbles is a data table, once clicked on produces the data in the background tables. In the lower left, is the THIRD level table and showing there is the capability to offer three separate MODES where another FOURTH data level blows out data tables that can be manipulated to change options when and under what conditions the flaps are opened and by how much (as a % of open). With the third level table and as an example, My Aston DB11 V12 has 3 modes - GT, S, S+. When I select any of these modes the ECU switches mode tables which changes the selections of valve opens as a %.




There is a page above all of this at the top level of the tune tables. Again, as a last comment, the dealer tech is not going to have a clue what is shown here. They only push the button that downloads this via the factory instructions in a SW flash. If this is in there, they can't validate is, only what the flash description is.



All of this is just exhaust flap controls. It is a completely different section of the tune files (fuel) that changes the pops crackles, etc. The flaps only contribute a lesser amount to noise level control.